Storm Australian Severe Weather Forum
Severe Weather Discussion => Australian Severe Storms, Weather Events and Storm Chasing => Topic started by: John Allen on 10 February 2010, 08:05:30 PM
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Hi guys,
Just got back from a long chase with brad, heres the first day of the action summary. Pics will follow when I have time:
Brad and I met up at Mount Cooper, decided to get north of dividing range and sit of the northern flank of the cells that were forming....we ended up seeing some fantastic vertical structure as storms were splitting willy nilly...im guessing because of the relatively straightline hodograph conditions...unfortunately we quickly realised that the split was usually follow by cell death, first the right then the left. Anyway, shot up through Whittlesea to avoid peak hour (just before 3pm), saw a couple mushroom cloud type updrafts and some interesting base structure with frequency CGs. Following this we continued up the Hume north, spotting a mid-level funnel on the way...i commented to brad that the rapid updraft formation was probably indicative of landspout potential (how right I was). An on the road check of weather conditions and a bit of sky scanning quickly suggested that North and Northeast were pretty much out with solid convection towards bendigo.
Numerous Mid-level funnels were spotted as we move west past Heathcote, and possibly coincided with Rikki's landspout....probably to our south in the low contrast environ. We skirted the edge of Bendigo eyeing off the dying storm to the south, and decided to pursue a storm near Maryborough which appeared to be left moving and intensifying...ended up west of Bendigo, through Eddington to Dunally, where we observed another nice cell with mid-level funnel features, and a couple of other weird things, plus numerous inflow bandings particularly as the cells organised. These cells and the Maryborough cell collapsed but a new storm formed to our east...on the road again following what was the Bendigo cell, while we were following this we noticed what appeared to be an isolated large wall cloud to the south, which was obscured by rain as the parent collapsed, and more mid-level funnel activity. The amount of clear air and CGs from the Bendigo right split was amazing....as was the collapse of the left cell...unfortunately we got stuck going through town when this cell was at its best. However, on the other side we noticed another cell develop and feed off the right partner, and gave chase...spotting an amazing corkscrew wall cloud with strong persistant funnel....had we not been attuned by the number of mid-level funnels seen we might have missed it but this event was far lower and much more impressive that anything else. Anyway as it disapated we set up on the final storm (last storm before diurnal end killed everything), it underwent a similar lifecycle to most cells of the day, moving slowly and developing good features with tilt and inflow band, then a rapid collapse as the slow progression resulted in the outflow being ingested. However the lighting allowed us to catch some stunning CG action...many double intertwined CGs and even a paralleled tripple with intertwine that was just unreal...a few crawlers and this cell ended the day.
I would say its one of the more amazing chases i've had in Victoria in terms of providing a huge range of different chasing items...while the storms weren't the most intense and often died at frustrating moments the slow movement and atmospheric instability were superb...potential for alot of daytime CGs, organisation, funnels, and alot of interesting phenomena. I can only hope that the shear tomorrow is more favourable to ensure a greater longevity. I should also state that while we covered alot of distance we were constantly chasing one storm or another and had to adjust targets accordingly. Will post pics when I can ...damn pest control people coming in the morning...and Ill be out again tomorrow afternoon.
In terms of day two targets:
Shear environ is certainly going to be alot more interesting...probably more likely to get squall lines with a straight but strong hodograph...depends how it reacts to -4 LIs and CAPE to 1700. Chase time is probably going to be similar to today as there is reasonable CIN with the plays dying on dusk unless convection is sustained. I wouldn't play too far west either as it looks like that area will stabilise in the afternoon. So target area is west of Melbourne along the seabreeze/convergence line.
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Hi John,
Good luck this evening with another chase.
I went for a walk last night and took some photos of a beautiful cell between Wodonga and Rutherglen.
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A few more storms around this afternoon, very glad that this horrid humidity has given way to something. It seems that the moment these storms get organised and start to look impressive, they die!
We recieved 15mm of rain and small hail in a storm that came over at 4pm, very gusty.
Lots of CG's pumping down amongst it all.
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Hi,
Got a couple of excited calls from Brad who is again with John chasing near Kilmore and surrounds. They were excited to see corkscrew updrafts, several wall clouds and beavr tails or inflow bands. Can't wait to hear more and see the pictures!
Regards,
Jimmy Deguara
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Fantastic photo John, I love it. If only something would happen here.
Just for the record today we had lots of nice buildup to the west, to the point I was keeping an eye on it while working on a roof at Ryde in case it started throwing out bolts. But everything stayed west and southwest of Sydney, with the sea breezes killing anything as it came off the mountains.
We did have a nice big anvil shelf come over the top from a storm a long way west so suspect the shear must have been pretty good up high.
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Awesome to see such excellent activity! I will await even more images from today's chase - sounded exciting after a 1hour and 2 minute phone call!
Regards,
Jimmy Deguara
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Hi sorry guys had to change the topic.
We had a few thunderstorms again today like yesterday some went severe. The one I went on had some half decent shelf and base structure but nothing too exciting.
(http://www.australiasevereweather.com/photography/photos/2010/0211jd06.jpg)
(http://www.australiasevereweather.com/photography/photos/2010/0211jd17.jpg)
These photographs were taken at Bilpin
Regards,
Jimmy Deguara
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Heres a few videos from the last two days. I didnt encounter any organised or severe storms,however I did witness some nice lightning.
Video 1- I intercept a weak storm near Marulan. Some of the lightning is quite nice with some discharges containing 4-5cgs! Some nice thunder included as well,with some of the closer bolts getting to within a kilometre
nice staccato lightning (http://www.youtube.com/watch?v=xkiNnWjc_as#normal)
Video 2- a nice but distant cg near Moss Vale this evening. The colours behind this bolt were quite spectacular. As I shot this with my 5d mark II HD video, I was able to zoom in on the bolt without losing much quality.
sunset lightning near Moss Vale (http://www.youtube.com/watch?v=JwQUfPpqXFU#normal)
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Despite this ridiculous hour :o I thought i'd post that John and I have a Thursday supercell count that goes into the teens (yes I know it sounds crazy but we'll put up the pics), two confirmed tornadoes (with video and pics), several others yet to be confirmed and require further investigation and a few more that we are very confident on (some were huge cone circulations practically on the ground) but may not be able to verify due to obscured views (despite the MANY ominous photos that we'll post as soon as we can). Also note that this doesnt include the miriad of substantial wall clouds, vertical and horizontal funnels that tried over and over to touch down, laminar inflow bands, beaver tails, storm structure and greenage that was jaw dropping and a landspout. We have a massive task ahead of us to go through this. Oh, and we had a simply awesome chase on Wednesday too which was until today the best I had experienced in Aus by far! After today I can barely remember it! :d
Thanks to John for his excellent forcast and targeting and thanks also to Jimmy for the advice and contribution over the phone and also for his company on the phone for an hour in an otherwise lonely and uneventful drive through Central and Northern Victoria! ;D
Brad
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Terrific news about the tornado intercepts - very much looking forward to seeing some of the images.
Here's some data for the day
Melbourne morning sounding
(http://australiasevereweather.com/storm_news/2010/soundings/2010021100melbourne.png)
GFS 06z analysis run showing winds in knots is rather revealing
(http://australiasevereweather.com/storm_news/2010/maps/2010021106wind1000.png)
(http://australiasevereweather.com/storm_news/2010/maps/2010021106wind0925.png)
(http://australiasevereweather.com/storm_news/2010/maps/2010021106wind0850.png)
(http://australiasevereweather.com/storm_news/2010/maps/2010021106wind0700.png)
(http://australiasevereweather.com/storm_news/2010/maps/2010021106wind0500.png)
(http://australiasevereweather.com/storm_news/2010/maps/2010021106wind0300.png)
The Melbourne Doppler is still offline which is a real shame. Loops from Melbourne Airport and Yarrawonga radars are available.
128km Radar Loop for Melbourne AP, 00:00 11/02/2010 to 10:00 11/02/2010 UTC
(http://www.theweatherchaser.com/radar-thumb/IDR513/2010-02-11-00/2010-02-11-10/300.s.png) (http://www.theweatherchaser.com/radar-loop/IDR513-melbourne-ap/2010-02-11-00/2010-02-11-10)
256km Radar Loop for Yarrawonga, 00:00 11/02/2010 to 10:00 11/02/2010 UTC
(http://www.theweatherchaser.com/radar-thumb/IDR492/2010-02-11-00/2010-02-11-10/300.s.png) (http://www.theweatherchaser.com/radar-loop/IDR492-yarrawonga/2010-02-11-00/2010-02-11-10)
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Hi guys,
Looks like VIC was the place to be this week! Glad you got out in it John and Brad, cant wait to see the photos, particularly of the structure and funnels!
Looks to be building around us (the Upper Western) here today. Nice Cu field and a few towers pushing up here and there. 36˚c, very humid and a nice breeze to create a little shear.
I'll be ready for anything :D
Take care,
Shauno
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Terrific news about the tornado intercepts - very much looking forward to seeing some of the images.
Here's some data for the day
Are those radar loops correct? I'm struggling to see anything 'organised' in those loops?
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Hi John,
Based on the scans from the Yarrawonga radar, and using 3D rapic we have identified these cells to be low-topped supercells, with tops probably not extending above 5km.
Wow! Was that the very large HP supercell or the smaller LP looking storms you mentioned in our conversations?
Did Harald comment on the pictures of the tornadoes?
Where are the pictures guys - at least post one or two on here!
Regards,
Jimmy Deguara
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Hi all, this is the first of 3 posts with some samples of what we got each day:
Note - Just minor adjustments to exposure, curves and sharpening where required.
Tues 9th Feb
(http://img42.imageshack.us/img42/6646/100210a.jpg) (http://img42.imageshack.us/i/100210a.jpg/)
(http://img175.imageshack.us/img175/8117/100210b.jpg) (http://img175.imageshack.us/i/100210b.jpg/)
(http://img193.imageshack.us/img193/3898/100210c.jpg) (http://img193.imageshack.us/i/100210c.jpg/)
(http://img27.imageshack.us/img27/8079/100210d.jpg) (http://img27.imageshack.us/i/100210d.jpg/)
(http://img52.imageshack.us/img52/7870/100210e.jpg) (http://img52.imageshack.us/i/100210e.jpg/)
(http://img205.imageshack.us/img205/9329/100210f.jpg) (http://img205.imageshack.us/i/100210f.jpg/)
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Wed 10th Feb:
(http://img6.imageshack.us/img6/8302/wed1w.jpg) (http://img6.imageshack.us/i/wed1w.jpg/)
(http://img218.imageshack.us/img218/6241/wed2o.jpg) (http://img218.imageshack.us/i/wed2o.jpg/)
(http://img175.imageshack.us/img175/796/wed3.jpg) (http://img175.imageshack.us/i/wed3.jpg/)
(http://img59.imageshack.us/img59/5285/wed4q.jpg) (http://img59.imageshack.us/i/wed4q.jpg/)
(http://img42.imageshack.us/img42/9959/wed5.jpg) (http://img42.imageshack.us/i/wed5.jpg/)
(http://img214.imageshack.us/img214/8131/wed6.jpg) (http://img214.imageshack.us/i/wed6.jpg/)
(http://img211.imageshack.us/img211/5691/wed7.jpg) (http://img211.imageshack.us/i/wed7.jpg/)
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Here's some shots from Thurs 11th Feb including tornado:
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Some more images from Thursday 11th Feb:
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And a few more to tide you over.....:
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Hi Brad,
Nice storms! Some interesting structures there too! Well done.
Can you please annotate the images so visitors are reminded which reference are the tornadoes eg photograph 09 is the ...
I see nice gust front interaction here. Seems like a gustnado exists in the dust - need to see some video as it is not exactly clear here. There is another phoograph which shows precipitation like column - can you place a few more pictures showing this as a sequence - thanks.
I assume the wedge status pictures are still to come.
Regards,
Jimmy Deguara
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Brad and John,
We any damage photographs taken beyond the road? Here is a link to the damage survey from the Dunoon multivortex tornadic event we suggested high end EF-1 possibly low end EF-2.
http://australiasevereweather.com/photography/stormdamage13.html (http://australiasevereweather.com/photography/stormdamage13.html)
http://australiasevereweather.com/photography/stormdamage12.html (http://australiasevereweather.com/photography/stormdamage12.html)
http://australiasevereweather.com/photography/stormdamage11.html (http://australiasevereweather.com/photography/stormdamage11.html)
On this page just below the Greensburg tornadic damage, there is a few year old damage from a tornado that crossed the road from a confirmed tornado 20km or so E of Coonabarabran.
http://australiasevereweather.com/photography/stormdamage05.html (http://australiasevereweather.com/photography/stormdamage05.html)
The region south of Walcha got hit by a tornado in 2002 which we gave a rating in the F2 range due to structural damage to a house but the tree damage was quite significant
http://australiansevereweather.com/storm_news/2002/docs/200210-01.htm (http://australiansevereweather.com/storm_news/2002/docs/200210-01.htm) towards the bottom
Regards,
Jimmy Deguara
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Storms Albury Wodonga Region February 8 2010
February 8, 2010, I decided to head to Albury Wodonga region for 4 days for a break which included some minor storm chasing and storm photography.
Late Monday, some thunderstorm activity had developed over the Kiewa Valley near Mt Bogong (North East Victoria) that tracked north west towards the twin cities. However being convective in nature they collapsed soon after sunset. Despite this, the cloud towers provide a spectacle late afternoon. The region has suffered from drought and low rainfall of recent times and any storms or rainfall activity is welcome.
The photos below are taken not long after I had arrived and are taken from Ellis Street Thurgoona looking south east toward the Kiewa Valley. It was not worth chasing this cell as it weakened not long after I had taken them.
Harley Pearman
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Storms Albury Wodonga February 9 2010
A similar pattern occurred again on February 9. Late afternoon storms developed largely across the same areas that tracked north west toward the twin cities. Convective storms propagated and decayed across terrain to the east and south east.
I found out that the storms were producing little rainfall but lightning was more of a concern and a few small fires were reported due to lightning strikes. Fortunately they were contained early. The first two photos show the cells propagating east of the twin cities or Lake Hume. I am taking these at Lavington looking east.
Late afternoon or evening, a storm propagated close to Albury Wodonga (third photo). It was elevated and produced minimal rainfall. Lightning was more of a concern due to the dry vegetation. This cell quickly decayed after I took some photos. The third photo is looking south west from Springdale Heights.
Harley Pearman
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Storms Albury Wodonga Region February 10 2010
There was more thunderstorm activity during the afternoon which increased in nature for a few hours. I managed to chase a storm around Huon Hill toward Bandiana which produced a substantial rain shower. That storm decayed soon after. Interesting the weather stations for the region did not indicate any rainfall falling anywhere. Hence it appears that the storm passed over a region that did not include a weather station to record it.
There was more afternoon thunderstorm activity but the problem was that too many storms developed. Cells were small and short sharp showers were occurring but decaying quickly. Eventually too much cloud cover inhibited any further storms late afternoon. Rainfall was short, sharp but highly localised. Again, given the nature of the vegetation, grass fires started by lightning strikes was more of an issue.
The 2 photos attached show the typical nature of the storms south of Wodonga taken on the Murray Valley Highway. This is one of many small but brief cells that developed. Similar cells developed around and near Mt Baranduda, toward Beechworth and even into the Kiewa Valley. Chasing was hard as the storms did not last long.
Harley Pearman
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Wagga Wagga rainstorm / Thunderstorm 12 February 2010
Friday 12 February 2010 I drove to Wagga Wagga under cloud and as I was approaching the city on the Olympic Way, I noted a thickening cloud cover to the north west not too far away from me. I stayed in Wagga Wagga to see what would happen as that cloud bank was headed directly toward the city. Light showers started to occur which increased in intensity.
Not long after midday a thunderstorm embedded in the rain / shower activity passed directly over the city producing a heavy downpour. Locals were caught by surprise. As this city has suffered drought and still in drought, people started to gaze out of windows of buildings and even stood outside watching it. This storm was truly embedded within the cloud cover. Gutters were overflowing and water was gushing across footpaths and roadways for a period.
I took this photo during the height of the storm under a shelter with other locals outside Wagga Wagga Markettown on Forsyth Street looking north west. This storm certainly put a smile on people's faces.
Harley Pearman
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Harley,
That storm on the 9th February 2010 in Albury looks severe - nice crisp side anvil. the distant base indicates that any features would have been about 20 to 30 km further to the southwest or west. It may have been in a weakening phase not long after this given the base seems to have closed in although it is hard to make a definite judgement from the image.
Regards,
Jimmy Deguara
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Albury storm 9 February 2010
Jimmy, I attach 2 additional photos of that storm near Albury or Nail Can Hill for your perusal and or comment. I am interested now and I provide you some additional comments to what I observed from my location.
One photo is taken earlier at 7.49 pm (Not 6.49 pm) and one photo is taken later at 8.08 pm (Not 7.08 pm) I was outdoors at 6.30 pm and only noticed some cumulus clouds in that vicinity or to the west of Albury. I did not see any thunderstorm clouds across that part of the sky. The day had been hot and generally sunny being 34 degrees Celsius but it was a dry heat. Storm cells had been building to the east and south. I was watching the western sky and between 7 pm and 8pm this cell developed.
Occasional thunder was audible after 7.30 pm. I could see a solid rain curtain fall from it and the anvil did spread north east overhead but as shown in the second photo taken at 8.08 pm, the storm is showing signs of weakening (Left hand side of the photo). I could again see clear sky to the west of the cell. I did not chase it because I was interested in a developing cumulus tower (Second photo) even closer to me and I thought that another storm would develop close to where I was. Unfortunately nothing occurred and the cloud broke apart after sunset. Generally the storm had a short life span.
The photos are looking west towards Nail Can Hill close to sunset.
Harley Pearman
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Brad and John,
We any damage photographs taken beyond the road? Here is a link to the damage survey from the Dunoon multivortex tornadic event we suggested high end EF-1 possibly low end EF-2.
Hi Jimmy, we found little significant damage away from the main path (side roads were investigated) which amazingly followed the general direction of the road and rail line for the distances John noted. The nature of the damage path is such that there is a bitumin road adjacent to a dual rail line with in turn is abutted by a dirt road - all running parallel to each other with farmland on both sides. Therefore the width of the road/rail is quite wide and the damage was often observed across the whole width, accounting for the estimates of width of the damage path being consistently 100m (or more at times).
Having looked at your links provided I would have to say we observed significant widespread tree damage and scattered tree debris very similar in nature to the Dunoon pics but no structural damage of any real note.
For those interested in the damage survey and the area in question, here is a map link showing the towns mentioned. The damage path/s follow the direction of the railway line (north east from Avenel) which has a bitumin road alongside on the south eastern side and a dirt road alongside on the north western side.
http://maps.google.com/maps?q=avenel+victoria&oe=UTF-8&ie=UTF8&hq=&hnear=Avenel+Victoria,+Australia&ei=acV4S8ewE4ugkQX8vOz5Cg&ved=0CAkQ8gEwAA&ll=-36.843087,145.352211&spn=0.196724,0.43808&z=12 (http://maps.google.com/maps?q=avenel+victoria&oe=UTF-8&ie=UTF8&hq=&hnear=Avenel+Victoria,+Australia&ei=acV4S8ewE4ugkQX8vOz5Cg&ved=0CAkQ8gEwAA&ll=-36.843087,145.352211&spn=0.196724,0.43808&z=12)
Our location during the storm when we were seeing, photographing and videoing intense storm behaviour was from Kirwans Bridge Longwood Rd generally looking SE to SSE towards Locksley and Avenel. Having reviewed photos (with high contrasting) and then found the damage path, the pieces of the jigsaw are coming together.
As John mentioned, reviewing our photos (in high contrast where necessary) revealed some amazing storm behaviour including a likely very large wide circulation with defined angular side walls (which we can now say corresponds well with the location of Avenel and Locksley) well before the action from the same storm closer to Longwood which produced the multi-vortice dusty tornado. It became apparent that a damage survey was appropriate so off we went. However, we werent anticipating the length and width of the damage path we would find, nor did we expect that we would find such impressive damage from as far southwest as Avenel. The nature of the damage includes significant amounts of grass flattened and clearly facing different directions, long thin grass reeds embedded and protruding under the rail line between the sleepers, many dozens of large gums damaged or brought down over long distances with many 100's of limbs and branches hanging in other trees or laying in different directions along the damage path. The evidence of vorticity throughout the damage path leaves us in no doubt that this was a tornadic event and matches our observations, photos and video at the time. Further investigation is needed closer to Longwood and on the eastern side of the Hume where our photos also indicate possible further tornadic behaviour including another suspicious looking large circulation to our SE becoming rain wrapped by a huge RFD as we raced NE up the Hume.
Brad.
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Nice pics and reports there Harley! well done.
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Brad and John,
You mentioned on the phone that there was debri cleared off the road by perhaps SES guys and you left that out. How did you get to distinguish those that were touched by workers from those that weren't? Furthermore, the trees in question in some cases seemed rather weak from years of drought I guess? Is this the case in some of the images? Finally, how many people did you try and interview? You talked about the one whom you interviewed and said it was a bit of wind and was not really interested - were there others? When there is a tornado, the noise sounding like a freight train is obvous even from 100 metres away as was the case in the Dunoon tornado since the damage path leads to the initial conclusion of a similar strength tornado in the preliminary estimates.
Regards,
Jimmy Deguara
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Hi Jimmy, to add to John's reply there were plenty of examples of substantial tree limbs that had been chainsawed and left in piles roadside but we didnt focus on those due to the plentiful undisturbed damage, the majority of which was healthy. Note that there was also significant older tree damage and fallen limbs which we discounted as likely being from the New Years Eve (squall?) that came through this area. The other thing I noted was tractor or front end loader tire tracks (in the fresh mud tracks left by roadside flash flooding) leading up to debris that had been pushed away from the road in a few places.
The guy I spoke to (who clearly wasnt interested in talking) lived within 50m of flattened long grass and some minor (compared to the rest) tree damage but was at the very start of the damage path as we observed. Keeping in mind the long damage path that was heading directly away from this house and the heavy rainfall it is quite possible that they heard nothing 'abnormal' in their opinion. Furthermore, along the entire lengths of the damage paths I recall seeing only one farm (set back 100's of metres from the road), one closed council maintenance yard, one small industrial plant and a cattle yard and thats about it. Hopefully the next stage of our investigation may find more locals closer to Longwood and the Hume.
Brad.
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Hi guys,
Sorry about my persistence here. I am just trying to make sense of the whole thing - the way the photographs are pointing, the alignment of the damage path, the height of the bases the types of structures. You guys have flooded us with so much information it is hard to keep up. I am sometimes wandering if that is why it is quiet in this thread - I mean we are talking tornado here!
Can you guys annotate the photographs indicating:
- the "large circulations"
- the tornado
- the damage path
Further to this, can you give us some exact comments from someone like Harald Richter in regards to the comments of the tornado and radar analysis. Yes I know it is a lot to ask but it will go along way to clearing a lot of what is going on in my head and my lack of experience with the mention of low topped supercells and tornadogenesis.
Regards,
Jimmy Deguara
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I guess some of us have been quiet despite following the thread because I haven't seen any obvious tornado touchown captured on the camera in the photos supplies so far (despite their being some fantastic structure and so on). I agree the damage evidence would suggest tornado damage based on my two experiences, one being near Naracoorte SA the day after an evening storm went through, and having the chance to check the damage on the Adelaide (Noarlunga) tornado that I also got to check out the day after last year. Probably hoping for some more nice funnel photos with them actually on the ground.
That said it is a fantastic chase report and some very in depth analysis happening here that I understand takes time because of the analysis that is being done. Instead of just photoing and moving on, I appreciate the effort to analyse what happened.
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John,
I would like to point out once again to anyone who believes that we are jumping at shadows that we have images that when contrasted show the likely Avenel touchdown, and many others....what we intially claimed (2 tornadoes) is far below what some might claim given some of the imagery we have...Brad and I desire to ensure we can verify each and every tornado as we go. Note that the current confirmed tornadoes tally stands at 5 individual tracks (not just photographed....you can see that in the pictures above a massive question for us is how many individual tornadoes are there....for instance...are the tracks we have identified thus far individual tornadoes or simply swathes of multiple vortices?...
Just post whatever higher quality or contrasted images you have with name plasted all over it of the actual tornado(s) where the funnel or bowl lowering below the base points to a circulation on the ground and annotate them. Also post some video of the rotation with the funnel/base/dust. I can assure you that I have video taken in poor lighting of dust and you clearly see rotation even at 110km/h and no tripod or stabilizer!
Are you able to post one image of the large cicular base please? There are not only one - but two of you that could assist each other? Storms have stopped all around - so more time in hand. I am asking for the text to picture ratio to decrease please. Also, post some video as that would at least reveal the major rotation being described here.
John, what is the separation distance between damage paths before a tornado can be classified as a separate tornado by definition?
A question in relation to the bridge and embedded grass - could flash flooding have been responsible for this? You talk about ample rainfall in the area.
In response to your claims that Bendigo has more tornadoes than this region thence the reasoning that people were not really expecting this - how do we know? Do we have sufficient data to support such claims? Schofields where I live has two tornadoes associated with it in the Bureau database and I doubt it is a tornado hotspot!
The most extraordinary component is the alignment along the road and railway track - bizzare. Note there is a kink of the road on the map. Can you trace the path of the tornado track on it please?
As Harald commented, what we observed was the absolute minimum to produce tornadoes, and the edge of supercell development...which makes it a very good example of why you need to be careful in TS forecasting.
I will message him privately about his thoughts.
One last thing, I will assume that I have permission to post the link of this thread for some US chasers/tornado researchers to see such Doswell and Davies et al who could provide some valuable comments and input into this bizzare situation?
Regards,
Jimmy Deguara
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The images above are of a gustnado. Jimmy can you post to CFDG and have this confirmed (or otherwise).......
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Hi Brad/John,
Firstly can I say what a great analysis you have written up so far on the event. Very detailed, you can tell a bit of time was spent preparing this. Some nice structure in the photos provided so far as well.
I'm with Jimmy here in regards to seeing the higher quality images you have and or video. Those 3 images you have put up are nice however look to me like outflow with possible gustnados on the edge. The clouds above looks a little messy, what you normally find with outflow. The last picture seems to show the leaning developing cumulus you find on the outflow flank as the cool air underneath pushes out forcing warm moist air upwards. There is even a little circulation wave on the left of the cumulus normally associated with outflow in picture 3.
I should also say the reception has been typical from any non-victorians (Jimmy excluded, mostly in other places)
My comments/thoughts above would have been posted had you been living/chasing in NSW, QLD, NT, Oklahoma etc etc. It's not the location of where the photos are that I base my comments on, it's what's in the actual photos themselves.
Well done on some great chasing. It's good to see people making the effort and heading out and you've certainly captured some great images.
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Hi John,
Please note down the reference to these definitions and are they related to the <5km storm height supercells you refer to? Are you suggesting that the gustnadoes are ingested into the main mesyclonic circulation in this case? What point are you trying to make in relation to your situation?
a US chaser would barely blink on a day like this...certainly wouldnt bother chasing, I therefore suggest we ask the experts...not chasers who may ignore an event like this
I think you are misjudging US chasers here. Unlike Australia, NWS researchers are also storm chasers in some cases. A tornado is a tornado and anything that resembles a tornado is mentioned as such and are not discounted I can assure you in tornado statistics. The dynamics that form them are a point for discussion. What you are trying to do here is create the massive discussion of text without providing sufficient evidence to back up the discussion visually. We are extremely confused and I in particular somehow cannot see a tornado personally even with the contrasted pictures. Please annotate them.
You mention about lack of time? Spend more time annotating the dynamics and less time writing these tedious posts!
Regards,
Jimmy Deguara
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John,
Tedious is the amount of posts that have been made questioning, making unfounded categorisations in ignorance of the large amount of evidence presented here
Where is the ignorance? In a scientific forum if you make a claim it is up to you to support the claim. You are the guys who saw the tornado so please get to the point of providing sufficient evidence. And don't worry I know about definitions of tornadoes.
I can assure you sufficient researchers have been notified but the shear volume of information may just be too much here.
Regards,
Jimmy Deguara
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Hi all,
Its an odd feeling (for me) to hear that some chasers in Victoria have bagged several tornadoes. First thoughts are "why the hell did I move to QLD...I have been here for 4 years (read: seasons) now and have not seen one and if I stayed in Vic I could've seen this". Second thoughts are "I should check the set up cause I can probably learn something".
I remember flicking through the GFS and MesoLaps charts on the day and thinking to myself in the morning "there should be some nice storms around today. Shear is decent, instability is nice, but there is no cap and it looks like the trough is going to surge eastwards as storms develop and push out some decent outflow". Also during the day, I kept an eye on radar given that my parents live in north central Vic. I remember thinking to myself "gee...this is nothing special...bit of a shame really" so I was quite surprised to hear reports of multiple tornadoes.
I also remember opening the forum to read the reports of the tornadoes and to see the pictures and saw Michael Bath's post with the GFS analysis charts. My thoughts..."Wow. The shear on those charts is pretty nice. Imagine what could've been had there been deep, isolated convection".
Then there was the detailed analysis from John and his discussion with Harald Richter. I found it odd, to say the least, that there was mention of low-topped supercells with tops of about 15,000ft which had produced multiple tornadoes - some things weren't adding up (apart from the fact that the Yarrawonga doppler is starting to reach the upper end of its range at about 100km).
Then there was the first few photos. Photos showing what look to be outflow features and cloud bases at or near 5000ft (pretty likely given the obs ahead of the storm/s was 33/16 as per several BoM AWS's in the vicinity). The whole adding up thing was getting more confusing.
With bases of 5000ft and tops ot 15,000ft that only leaves 10,000ft of actual updraft to generate strong enough rotation to spawn several tornadoes. Now I would think that this may only be possible in the case of some extreme updrafts. So...how unstable was it? Not *that* unstable. "Low CAPE" as per John's description. Could the stretching of the updraft come from extreme shear (as opposed to extreme instability)? Probably not. With bases of 5000ft (lets say 850mb) and tops of 15,000ft (lets say 500mb for ease and conservatism) and looking at the GFS analysis charts posted by MB, we have northerly winds of 30-35knts at 850mb and north westerly winds of 40-45knts at 500mb. So really only 10knts difference between the two - not a huge amount of stretching going on here from shear (speed). Note that directional shear isn't overly useful in these situations - more on that in a separate post if people want me to go into it.
So no extreme CAPE, no significant speed shear...so where is this coming from?
My thoughts after reviewing ALL of the posted photos, reports, obs and data in quite a bit of detail...
I believe this to have been an outflow event. With the strength of the winds in the lower and mid levels, it wouldn't take much to drag these winds to the surface and generate some strong outflow. Couple this with some decent moisture (by Victorian standards), and you have some nice lowish outflow features (as shown in the pictures). Push this outflow across some slightly variable terrain and you have great potential for gustnadoes.
I chased a similar event (slightly further north) back in November 2003 which saw some strong outflow winds of up to 100km/h kick off some gustnadoes which I estimate had winds of up to and possibly more than 140km/h. I watched one of these significant gustnadoes (dust up to 500m in the air) hit a single tree in a paddock and the tree was reduced to a mess of mangled stumps with the branches thrown 100m up in the air and they came down at least that distance away from where they were previously rooted. This gustnado persisted for approximately 2.5-3km (which didn't take long as it was moving at 80+km/h. Photos of the chase (not the gustnado - was driving at the time) here (base levels and lowerings not dissimilar to Brad/John's photos)... http://macca.bsch.au.com/gallery2/v/Chase-Season-03-04/20031120/ (http://macca.bsch.au.com/gallery2/v/Chase-Season-03-04/20031120/)
Whilst I don't doubt the claims of sizeable ground level rotation, what I beleive is that these were gustnadoes - and some pretty strong ones at that. The damage photos indicate winds of up to and probably in excess of 100km/h.
This shouldn't take anything away from Brad and John who had one of the best chases in Victoria in recent times. To get that close to a strong gustnado and to get photos and video AND do damage assessments and observations, etc is certainly highly impressive (and given the complete lack of decent storms up here in recent times, I'd take it for sure). I really hope that this doesn't discourage anyone from posting reports or thoughts on this forum as this is what it is all about - seeing, reporting, analysing and concluding. What is important about these events is that there is this significant level of post-event analysis done to ensure that the correct outcome is reached - and in this case, I think it has been.
Macca
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John,
You have jumped the gun in suggesting people are saying you are lying. This is about trying get a correct outcome as Andrew suggests in the above post. I believe even before posting the first post on this event it appears you knew this was going to happen. What has happened is that instead of asking others to give some input, you have gone outright and suggested definite tornado and the scenario in play. Could it be a gustnado I mean seriously can it be ruled out? I have seen and chased this type of setup a few times and even whilst on the phone trying to make sense of what was going on and I was not making any judgement - this type of outflow dominant scenario is what was crossing my mind. The photographs did not in any way veer from what I had anticipated. I saw gustnadoes as well on most if not all the cases I have mentioned NOTHING as strong as what is being suggested here.
However, instead of jumping the gun I have personally allowed the discussion to continue some days now to allow for the evidence to be forth coming. As Macca says, this is a great example of gustnado behaviour. If there was a connection, you would see some sort of funnel dipping from the cloud base.
(http://www.australiasevereweather.com/photography/photos/1999/1122jd19.jpg)
Is this a tornado?
http://www.australiasevereweather.com/video/movies/1999/1122jd01.wmv (http://www.australiasevereweather.com/video/movies/1999/1122jd01.wmv)
At the time, I presented without any experience in the field despite chasing for the past 6 years at the time as a tornado. David Croan at the time came out and suggested gustnado. I did not argue the contrary. I had to accept from someone who had researched far more in severe weather meteorology. This is not to take away from a great observation from a very large storm.
As to the Clyve situation, what I commented at the time from memory was on the wedge status - yes again! Anyway that is cleared when sufficient photographs were passed across, I become more convinced.
I think Andrew MacDonald explains very well his thoughts and suggestions. Perhaps it could be adopted in this case. Perhaps not. But please have an open mind - we have.
Regards,
Jimmy Deguara
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Hello everyone.....and there's probably quite a few reading this I would imagine ;D
Firstly I dont have the met knowledge or enough experience to enter into any 'absolute' discussion about this event, and I dont pretend to. Those of you who know me would agree thats my usual approach I would hope. Therefore I base my communication of storm chasing and my opinion based purely on obs of storm behaviour at the time and then photo/video later. I may not have the scientific explanation for a particular event or feature but I consider myself a good judge of storm behaviour on the fly and I've been lucky to see a lot of impressive storms and tornados in the US - thanks Jimmy and Macca.
Therefore, I hope with all due respect to those who have much more theoretical and field knowledge and experience than I, that with more photos (including high-contrast comparo's) and video (which I will put up when I get a cable) although its not very helpful, the assessments may swing back toward this being a tornadic event with, if anything possible gustnadoes on the forward flank. But, personally, I have always considered gustnadoes NOT to be connected to cloud base - perhaps I am wrong.
With all due respect, the dynamics of what was happening embedded in the murk that we now know is the direction of Avenel (hopefully the pics will show you) and also on the emerging forward flank later was, in my limited but increasing experience not primarily gustnado and I would hesitate to say not gustnado at all. I did not see one vortice that was not connected to cloud base and outflow or not it seems to make no difference the way I see it, especially if the vortices are connected to cloud base.
Finally, just to ensure everyone is clear - there was a lot of evidence to the naked eye that this storm was exhibiting areas of distinct rotation and rapid development of very low bases and possible tornado a long time before the storm got to Longwood. I think the photos combined with the damage path support this. I'll do my best to get them up tonight but I have 2 (yes two!) sick kids and a grumpy wife at home so no promises :o
Regards,
Brad.
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Hi guys,
To add to the discussion, I post a very informative web page. A lot can occur within any storm supercell or non-supercell:
http://www.stormeyes.org/tornado/faq/notahose.htm (http://www.stormeyes.org/tornado/faq/notahose.htm)
Brad, we are looking forward to whatever you can provide to assist in this ongoing investigation. I hope unlike John, you are not too frustrated. It is a discussion after all.
Regards,
Jimmy Deguar
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I'll reply in more detail tonight (it'll take me a month to read John's latest post) but if there are any more conclusive photos, now would be a VERY handy time to post them...poor contrast or not. It is VERY had for anyone to conclude otherwise if there is no further evidence of tornadic activities. Not saying that there is not, i'm just saying put the bloody things up so we can see them!
One thing I'll note immediately. Temperatures and DP's in the area where these storms moved into during the afternoon were in the vicinity of 33-34C and 16-17C respectively. Not overly high even for Victorian standards.
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Hi John,
once a storm becomes outflow dominated it dies
I am not so sure about this - not always. They could become elevated and very disorganised but not necessarily die. I would have thought that when outflow cuts off inflow is when a storm dies.
Well...its like me coming out and saying...well the Dunoon tornado was actually a remarkable gustnado?
You can certainly welcome to go to the Dunoon tornado thread and suggest so if you so wish. I have even had one person come to me and suggest "Was it actually a tornado?" I explained my reasoning and then it is up that person whether they wish to differ in opinion. He accepted it.
Can I see the original image of the photograph you just posted so I can get a perspective of the whole storm related structure. Thanks for annotating the image - well done! Now we can see more f what is going on.
Regards,
Jimmy Deguara
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I have just done some googling for possible damage reports/images/videos related to this event in northern Victoria but haven't had any luck. The local ABC reports little damage from the 11th - though of course if tornadoes did form and luckily didn't hit any houses etc that would be the case. I thought that someone who didn't really know what they were seeing might have posted a picture in any case somewhere.
Oh well, was hoping I could find some other supporting evidence, with the number of camera/video phones out there these days had hoped someone might have posted something. So regrettably the search results don't really help or hinder the discussions. I will leave it to those with more meteorological knowledge than myself to disect the pictures and evidence, and watch on with interest.
That said John and Brad - I for one appreciate the extra time you are spending in analysing damage tracks etc and comparing to radar echoes rather than the usual "here is the photo/video" - and move on.
http://www.abc.net.au/news/stories/2010/02/12/2817969.htm?site=goulburnmurray (http://www.abc.net.au/news/stories/2010/02/12/2817969.htm?site=goulburnmurray)
More stormy weather forecast
Stormy weather is expected to continue in the Goulburn Murray region in coming days.
There was little damage from storms yesterday and rainfall ranging from five to 20 millimetres.
Dean Scarbossa from the weather bureau says storm conditions will ease today but he says they are likely to stay well into next week.
"For at least the next seven days it looks like it will be a similar situation," he said.
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The thing to remember about tornadoes is that like clouds they came in lots of different forms and often they can be obscured. The photo above certainly looks like a vortex. The Melbourne sounding shows a strong upper NW flow which I think is the primary ingredient to look for. The low level enhanced shear will not show up in any modeling. Looks like some interesting storm days for you guys.
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Ok after a very late night of sick kids and falling asleep at the PC :o I have gathered all my useful photos (i dont have John's) relevant to both the Kilmore and Avenel/Longwood events. From over 100 raw files I've processed a clean unedited .jpg as well as a contrasted .jpg image for comparison. I will put some up now and more tonight after work. I have many more others that add to the visual picture of what we were witnessing so they can be added later. I dont have the time nor the mental state right now to add commentary to the images but I or John will try and add that later. In the meantime, the images are numbered and presented in order and remember they are only of the two events mentioned above - they do not include pics of all of the other cells, wall clouds and significant funnels we chased all the way to the south of Beechworth that day.
So, starting with Kilmore where my chase officialy started at the southern end of town and by the northern outskirts we had a fully developed wall cloud and then this!:
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One more of Kilmore, then another from a new base as we moved north.
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You will notice that there are not mny shots between the images presented here despite the base features shown being different cells (John correct me if I'm wrong) as we went north which gives some idea of what we were experiencing that day. Cow pics are from NW of Longwood looking south generally towards Avenel:
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I will add a few stitched pano's of this scene as well as some wide angles
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I will add a few stitched pano's of this scene as well as some wide angles
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Another wide angle with contrasting:
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This cell now started to exhibit signs of strengthening with very low base features
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Some more wide angles at the time where we were very confident of what we were seeing in the behaviour of the base features:
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Base features consolidating between images:
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This storm is rocking now and there are clear base features and possible large circulation visible to the naked eye:
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This storm is rocking now and there are clear base features and possible large circulation visible to the naked eye:
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The storm is SW of Longwood now and part of it emerges and picks up dust from open fields that we later located during our damage survey:
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The storm is SW of Longwood now and part of it emerges and picks up dust from open fields that we later located during our damage survey - note there is still a lot of interesting activity occuring behind (to the right of these image)where we had been watching very closely:
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at this stage RFD is aproaching us from the west (from the right in the images) and we have to move plus we need to move quick to ensure we beat the circulation to Longwood and our NE option on or alongside the Hume. The main circulation and base-feature activity we had been watching is now being rain wrapped as RFD moves through and crosses the Hume but there is still some substantial dark base features in the pics. These large funnels reach out a long ay in front of the storm and even keep up with us for a while.
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We eventually gain some space which allows us to pull over and view the storm which is now a large tall precip wall and a few interesting features! There is more to come but I have to go to work in Geelong, as long as I dont fall asleep that is!
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Hi John and Brad,
Thanks very much for your detailed posts and photos, it's great to finally have gotten a few more images of everything!
Ultimately, no one is here to "belittle" you or anything like that - people are just here to give their own opinion, and then it's up to others if they wish to take that on board or not. It definitely isn't a "northerner vs southerner" thing - everyone is equally ecstatic when they see great storms (and their associated photos!) in other locations, I can vouch that I have many NSW and QLD friends who will flick me a message saying "Wow, have you seen the Vic/SA/WA/NT etc etc photos???"
From the photos you have illustrated, it is my belief that this is an outflow feature. It appears to be a nice gust front that has developed thanks to the higher than usual humidity over Victoria. I hope this isn't taken the wrong way...but I've seen dozens and dozens of storms like that and I'd all call it the same thing (a gust front). There does indeed to appear to be a raised vortex though - and that would most likely be a gustnado if that's the case. Gustnadoes can be quite exciting - I remember on one great day (a 196km/h gust was reported from one of the storms too!) that Dave Sercombe and I had to stop on the highway with our hazards on (to stop people from proceeding) as a strong and defined gustnado crossed in front of us! We saw it from a while away too, and there were several other vorticies in the outflow push of this particular storm - there may have even been a small funnel above reported from another chaser. I believe that gustnadoes are quite common - especially if viewed from the angle that you witnissed it. If you think about it, if you are looking parallel to the wind motion ie:
x (x = your position
<---------------------- (inflow winds, 30km/h)
O O O (O = vortex rolls)
----------------------> (outflow push direction 100km/h)
From this angle, you'd see them easily (note if you were at the wrong angle, you may not witness it so easily). Again, it even reminds me of another storm which had winds of 130km/h (and some one was killed just near us from a tree falling on their car), but the dust front/gust front had multiple vorticies on the front of the storm - many short lived, but nonetheless definied. The above schematic could also occur on either the horizontal or vertical plane (ie, you could have tilted vorticity if the strong winds undercut the inflow, so it's inflow above and outflow below - the lifting of the warmer air on the boundary of the outflow could then tilt the horizontal vorticity and then connect the two briefly). There are many dynamics at work here.
Also - outflow dominated storms don't necessarily die either. And sometimes outflow dominated storms can become inflow dominated again! They're very dynamic...other times outflow dominated storms can become "front loading" (meaning that the outflow is generating the new updrafts just ahead of it, common in squall lines). A common feature for prolonged HP supercells in say NE NSW and SE QLD is to pulse, the outflow pushes through and the storm weakens briefly and then reintensifies again as the inflow becomes established (common near the coast with strong seabreezes, as the outflow eventually gets overcome by the stronger northerly winds).
No one's opinions should take away from your experience though! Either way you should be excited about what you saw - and it has been great to see some photos of the storms down there!
AC
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The photos in Brads pics Post 76/77, with the initial earlier posts (post 20) I had assumed the storm was traveling left to right in the frame but reading though it appears it is right to left?? just for reference sake could you confirm what direction you were looking when taking these pics (Brad had mentioned you were looking SE to SSE?) and also direction of storm movement.
The second pic in post 77 seems to show a funnel extending from the cloud base. (I was looking upper right hand side rather than the area highlighted in your last post)
So here's my two cents worth.. I don't like the term Gustnado full stop for cloud/associated feature classification, (nado is not a word which has anything to do with weather)so the coined term should be viewed along the same lines of using a term such as willy willy.
Fully agree with John about the terms useage, if a gust front spin up shows signs of attachment to the cloud base it ceases to be a gustnado(if the term is insisted upon). If formation of tornadoes of any form, was bias toward those lacking well defined condensation funnels in Australia it wouldn't be hard to see many being incorrectly termed as gustnados.
This topic has certainly been an interesting read keep it up, As for the case being discused photos don't do justice in showing the whole processes involved/suggested, hope to see some video footage.
Cheers
Paul
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Our problem here is that people are judging the storm purely on one feature which was clearly not the feature that caused the extended damage tracks...the damage was caused 10km earlier, and you can see behind the feature upon you are so fixated a defined tailcloud and a dark shape with quite hard edges in the murk. The tail cloud alone suggests this thing may have had a wall cloud....and this would be reflective of all the other storms we have shown prior to this image, which display wall clouds, and some also produce tails.
I still have a problem with the discussion of the "gustnado" against the nomenclature...given...the minute it reaches the cloud it is no longer a gustnado by definition...and yet noone has offered comment or even tried to say anything here...its just being ignored. If it was a gustnado then why were there associated funnels...not small ones, but ones that were miscoloured by the ingestion of dust? Why also did these features extend from the cloud...only to retract thereafter?
And an annotated point to so look at the the correct bit. We have the remenants of the prior funnel to the right, and an extended vortex tube which is discoloured by the dust and is contacting the ground. Can we please explain this...see the images either side of this blowup for evolution, noting the pin-funnel following this object.
(http://i60.photobucket.com/albums/h9/Xebadir/TornadoN.jpg)
Great discussion so far!
John with regards to your above image I have noted you have outlines in red what you believe is the vortex and associated debris underneath (Correct me if I am wrong). I believe what you have outlined in your photo are two separate features. I will explain using my dodgy photoshop skills below.
(http://sydneystormchasers.com/system/files/images/Disc1-connetion.jpg)
The above image comprises 3 images taken in sequence of the proposed tornado. The last photo above is pretty much taken at the exact time your coloured example above is (just not as contrasted). A couple of thoughts on this below
- The arrow above shows the leading edge of a gust front (which your calling a tail cloud) however in the last photo the way that the dust and leading edge are lined up looks like they are connected. Clearly from the first two photos they are not
- Using the mountain in the background the gust front (which your calling a tail cloud) is moving away (or out) from the main storm as the photos progress.
- In my opinion the dust cloud in the first of those three pictures does not line up underneath the darker "tail cloud" you are talking about. The dust cloud is or so away whilst the "tail cloud' looks to be 2-3km away
- The discolouring you talk about in the third photo is the top of the dust plume in the second photo being pushed out by outflow winds so it is located in front of the leading edge of the guster (or tail cloud). It looks a little dusty but its not. That dust is still a km or two in front of that feature.
- I can see the little funnely notches you are talking about however there is no connection in any of those photos that link the dust debris cloud to the cloud base (besides I believe the notch to be further back than the dust - see above)
Those above to me (plus seeing these sort of features so many times over my 11 years chasing) show clear evidence that it is purely outflow in those photos. I have also pasted a reference below of wall cloud/shelf cloud definitions taken from the NSSL (Keeping in mind the sloping edge of the guster [what you refer to as a tail cloud] in the above pictures as it moves away from the rain on the right - http://www.nssl.noaa.gov/primer/tstorm/tst_detecting.html (http://www.nssl.noaa.gov/primer/tstorm/tst_detecting.html)
To tell the difference between wall clouds and shelf or roll clouds, remember a wall cloud 1) suggests inflow and an updraft, 2) maintains its position with respect to rain, and 3) slopes upward away from the precipitation area. In contrast, shelf clouds 1) suggest downdraft and outflow, 2) move away from rain, 3) slope downward away from the precipitation area.
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Hi John,
In reference to your photo I largely have to agree with James' summary. It is perhaps that that photo is in the right place at the right time to capture an outflow prong with the dust vortex. I've also been chasing for 11 years, I've chased with quite a few people on this forum also (Jimmy, James, Macca etc) - especially back in the late 90s/early 2000 days. And I remember us all getting very excited when we saw dust etc rise up, and we'd then go back and have to examine the video footage and we'd look for movement etc. Much of it came to it being some of our first adventures, and us being very excited and eager to see (find?) tornadoes. But later inspection (especially with current knowledge) pretty much all suggests the same - that many (although not all) were not tornadoes, but they certainly looked the part for a brief period.
The features you have illustrated in photos are very common in NE NSW/SE QLD storms - and when I see them I often think outflow. I have seen wall clouds turn into gust fronts, and even gust fronts become remodified into wallclouds too! Weather is certainly very dynamic that's for sure. Hopefully as you become more experienced at chasing, you'll understand a bit more about what some of the comments have been said. That's one of the great things I love about chasing, it doesn't matter how long you chase for, there's always something new to be learnt!
Which Boonah storm are you talking about? Is this the storm last Monday? If so - I don't believe this to be a supercell? I even mentioned that in my posts on the Weatherzone Forum, a few people argued that it was a supercell and I disagreed with them. See: http://forum.weatherzone.com.au/ubbthreads.php?ubb=showflat&Number=833017&page=11 (http://forum.weatherzone.com.au/ubbthreads.php?ubb=showflat&Number=833017&page=11) and then page 12 for more discussion, and page 10 for the photo.
AC
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Hey everyone
Thought i would weigh in at this point with nothing more than to say that the discussion as been great so far - and that I support the comments from my esteemed colleagues above (Macca, James, AC). These matters are difficult - ones diagnosing skills are honed after years of chasing and questioning - most oft in the lamenting the big day that didn't quite fire - or that day where the cyclical meso developed a plethora of funnels but not that cherished tornado.
Being on the ground, in the environment - you eye and experience captures more than even the best photograph or video (Wingle angle HD or not) can. However endeavours of weather and chasing exist in the realm of science - and thus supportive evidence and the methods must be followed to support our aims and claims. The process of discussion and openess should be cherished and encouraged in all forums. The open ended question is oft of more benefit than the closed focused conclusion.
Great work in the documentation of these storms and damage surverys.
D.
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The only way which this will be resolved one way or another is to see the video. Obviously many of us are struggling to visualise what John and Brad are referring to in the still images. Personally, even with the red drawings showing the said funnels, etc, I'm still struggling to determine whether these are in fact rotating funnels or just scud features (commonly referred to as scudnadoes) - again this will come down to the video and what can be seen in terms of motion.
Until then, this debate seems somewhat fruitless. Any arguments to the contrary of this being a tornado are being shot down with lengthy repeated comments which all the seem to be doing are increasing the length of this thread. Whilst I enjoy the debate and discussion, its getting a little tedious.
The features in the photos suggested to be "wall clouds" are again hard to assess in still images. Wall clouds are usually associated with strong updrafts (again which I suggested in an earlier post were unlikely given the situation on the day).
There is definitely no doubt that Victoria gets a pretty decent number of non-supercellular tornadoes/funnels (of which I've seen plenty and have seen photographic evidence of plenty). Perhaps this is where we should be looking to categorise this event (as opposed to the short, low topped supercells referred to by John). To me, this environment is not one that could've or should've produced a supercell - whether it had tops of 50,000ft or 15,000ft.
I *eagerly* await this video. In the mean time, I'm off to look at photos of the tornado from the Atherton Tablelands from yesterday - definitely no doubt about this one (the question is, was it a supercell...).
Macca
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Hi John,
So hang on...does this mean you are contesting this as being an inflow feature.
Yep - shelf cloud to me.
Sorry I am exhausted. I am not going to comment any more until more funnel related pictures are presented or video of rapid rotation like I see with tornadoes. Excuse my narrow mindidness but count me out of the topic discussion. Brad thanks for posting your excellent pictures - they really show a very nice high contrast shelf cloud. Perhaps there were connection with gustnado at some point - perhaps not. I wasn't there you guys were. Unfortunately when you have to go to the trouble of enhancing and enlarging and annotating, the evidence is unfortunately poor to convince others who were not there. Maybe you did see a tornado - can't rule out the possibility. What I see is at least gustnado. At least we all tend to agree with that. I have seen several potential Australian tornadoes - I have only really claimed one! US tornadoes not a problem.
Thanks for all others for your comments and feel free to keep posting. John, please get Harald Richter to send actual comments of radar and so forth that points the wind shear couplets suggesting shear profiles of a tornado and low topped supercell conditions. To me the storms were much higher than that from what I could see. Like Anthony said, we have chased and observed these type of features many times before.
Regards,
Jimmy Deguara
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Well I must say I am very disappointed. Not in the opinions presented in this thread and not so much in the general concensus that the majority of posters have arrived at regarding this event. What I am most disappointed about is the manner in which some people who have participated in this thread have communicated their view, or in many instances in my opinion failed to communicate.
Throughout the last 6 very hectic days I have at times been astounded, frustrated and even angered and insulted by some of the statements and fairly obvious inferences made by some people I dont know and some I do know. Some of it has been about the storm itself and some has been about the 'lack of evidence' and apparent delay in putting images up. Right from the start we made it abundantly clear verbally and in this forum (and another) that it would take time to share imagery and observations of this event with everyone. No one should have to justify how their work and home life is limiting how much spare time they have available for this work - I have felt several times that I should have to explain. Even as recent as today after the images were posted there have been more comments inferring there had been a delay in ‘finally’ providing 'evidence'.
However, of most concern to me is the manner in which it appears some forum members have come to their conclusions (which is their right of course) but while doing so (at least in the public arena of the forum) have steadfastly ignored facts that were REPEATEDLY presented, field observations backed by reasonable evidence in images and a long and wide damage track, expert opinions and legitimate questions REPEATEDLY posed to the open forum and also to individuals - particularly from John but a few from me.
I have seen it stated several times in this topic that if you present scientific claims such as the presence of a tornado then you need to provide evidence and be open to scrutiny - that is a given, but it works both ways. Every question that has been asked of us we have endeavoured to answer it. Every theory, suggestion, comment or opinion made, however detailed or lengthy or short and unhelpful we have tried to respond to whether it was to further the discussion or offer a rebuke in the hope of finding the answer. The same absolutely cannot be said in many instances from other posters in this thread.
I don’t expect any responses to these examples, but the lack of discussion and style of communication on these particular issues has been extraordinary. I think they speak for themselves:
1. Apart from a mention by Macca, why is it that everyone seems so focussed on categorising the dust whirls rather than looking at the possibility of a large, persistent circulation shown as a large cone shape with defined side edges (in many of my enhanced images) in the direction of Avenel where there just happens to be 4 long and relatively wide damage paths? I could see the silhouette at the time but wasn’t 100% sure of course. We now have some evidence in the photos and we have a long damage path displaying consistent and clear vorticity damage. People have made very definitive comments about gustnados and outflow and yet barely a peep of discussion about any of this part of the storm which is the most impressive in my opinion. Any wonder John has been repeating himself.
2. Why is there no opinion or comment offered about John’s rebuke to the theory that the damage paths were caused by gustnados? He poses reasonable questions and provides scientific rationale and yet the response again is silence.
3. Why is there ongoing silence when John and I have both queried the use of the term gustnado repeatedly in this instance, which by definition (as I understand it) does not come into contact with cloud base? No one has corrected me and yet many comments have been made linking the forward flank features in my images with gustnados and making outright comments about outflow and yet there is evidence of at least some connection with cloud base, despite one fair opinion presented about possible parallax errors. If nothing else it seems the wrong terminology is being used and John and I are correct to point this out unless someone informs us we are wrong – no one has.
4. Speaking of outflow, there was none. It’s been said many times by John and yet it seems to be ignored rather than acknowledged or discussed. There was an RFD but there were no outflow winds at all when we were on the storm. As John has stated, we even had inflow with dust just to the north east of Longwood minutes after my dusty images. No one has responded to these points or questions but the concensus reached is an outflow event. Surely some discussion would have been worthwhile but clearly our observations are not considered solid unless there is video.
5. The reason John has repeated himself in this topic has not been for his personal benefit but because it is clear that some important issues are either being ignored (perhaps for good reason) or misunderstood, all the while people are announcing their absolute opinions about gustnadoes and outflow whilst contributing very little if any value to the topic. Very little acknowledgement or discussion on the issues above was entered into and yet John’s efforts to persist on certain issues and have some dialogue results in his posts being referred to as tedious. This is poor form and undeserved in my opinion.
6. I have a small amount of video of both the Kilmore and Longwood events but it is short (ten mins or so because it was a tape of my kids I had decide to partially tape over) and I would have to say it’s not going to alter any opinions expressed so far. I’ve never inferred otherwise, nor have I commented the video is good so a few who have commented about looking forward to seeing the video have assumed it would be of value. Video was a low priority at the time, John took some for me but was unfamiliar with the camera and was planning our road options and I was photographing and driving. I will post it though when I can – more than happy to but I need to find a capture card cable first.
Brad.
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Hi Brad,
Video was a low priority at the time...
Video unfortunately would have gone a long way to consolidating the argument. Even badly shot video would have shown rotation of a vortex. Make it a priority in the future.
Regards,
Jimmy Deguara
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Brad,
I still don't think I'm clear which photos you are referring to regarding the smooth-edges thingy looking towards Avenel. I've been back through the photos again just now and used the most rudimentary (paint) way of doing something...
Is what I've circled the feature you are referring to?
(no idea if I've attached the photo correctly).
Macca
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Managed to get some depth (stereo view)out of photos "IMG_1208_contrast" &" IMG_1209_contrast" certainly looks far more impressive viewed in 3D. Haven't worked out the exact position the photos were taken from - no street view on Google maps on that particular road, but either way, the rotating area of dust at ground level appears to be app 150m across and has a nice structure.
It also seems to support a connection at that time to a vortex as outlined by John in post 86 (image 2). Having said that, one would require higher resolution and probably better parallax to conclusively state on the basis of those 2 images alone (without video or actually witnessing the event) that it is connected, and also a further sequence of photos(hence video is best, bigger sequence)to give an indication of rotation of the vortex.
Cheers
Paul
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John, Brad,
Briefly off-topic, I have already clarified the reason for the brevity of my two posts offline with John (ie I'm just way too bust to spend the time that I would otherwise like to in reading and contributing to the forum, Jimmy would vouch for that), so I wont go into that aspect much more, other than to say there is no malice in it and, I guess I can be abrupt in my posts.
The bowl lowering that Macca has captioned above could well be a large bowl funnel based on it's appearance in that pic (and I have not gone through the preceding posts in detail to gain a perspective from different photos), there's no question of that. If the shelf / collar at the front was part of a broader scale circulation and if the bowl was clearly rotating, case closed. On the other hand if the shelf was pushing out and that feature was going with the flow so to speak, and if rotation was not discernible to either of you, I would be fairly confident in saying that it is just a non-descript lowering... a tornado wanna be. When chasing, large rotating lowerings of that size, which are indicative of a low level mesocyclone, are unmistakable even from some distance -- since they are basically a pivot - your eyes are drawn to them even if they are moving as part of the storm, in that all the other cloud base elements appear to converge on them and move around them...it really is an unmistakable process visually. SO like I said, if that is what you saw then it is what it is. I'll offer comments on the dusty tornado later, but reasoning was pretty much what has been covered. If there are more pics now available of that phase, ie zoomed out etc etc, I'll look at those and give my own thoughts.
I was trying to find a good example of a similar cloud structure that is tornadic and one that is not....I'll have to use my own examples as I think White Deer had an excellent bowl lowering prior to tornadogenesis being fully realised.
I thought this (Booleroo) might be a good example, but after looking at it, thought no. Nice tornado nonetheless. btw I don't agree with it being multi-vortex....as is/was claimed ....that's scud appearing to break up the single tornado vortex.
This is the Booleroo tornado taken in 1992 referred to above.
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Thanks to those that have contributed more to this topic today.
Hi Paul, thanks for that info. Can you post any imagery at all? Have you considered that process on earlier images such as 1184 onwards as per the discussion below?
Hi Macca, you are zero'ing in on the correct part of the storm in relation to my comments about the large distinct cone ;) but you have circled only part of the feature (which is also what I was initially drawn to in my photos) i'm referring to. The feature you circled is clearly obvious in my pics with no enhancement and we could see it visually at the time, however we could see more behaviour further behind and much lower to ground than that but I didnt realise there was any evidence in the pics until the weekend when I contrasted them. I thought it was pretty obvious in my contrasted images without annotating the pics directly but thats ok. I will put up some larger versions of the images in question friday arvo/evening to help clear up the confusion, and remember this direction (looking generally SSW from NW of Longwood) corresponds very well with the damage path/s location.
Hi David, in reference to the features in the pics I will re-post in larger versions (and our obs at the time) , you basically nailed the situation as I saw it with your description of what you would expect to see if there was a large rotating lowering associated with a low level meso which John is sure was present.
I think there is evidence of inflow coinciding with this part of the storm organising and producing a sustained lowering well below and further back from the obvious collar. Subsequently and with CS3 contrasting there are well defined edges to a possible large cone circulation which can be seen in a number of my images – the feature circled by Macca is only the top right hand edge of this larger feature which I could see with the naked eye and is the main reason for the number of photos I took of the storm at this moment.
I think your reference to collar is fitting as it was not gusting out like a shelf, in fact it built and consolidated as I think can be seen from pic 1115 onwards, with obvious flow into it from the western side as the storm moved slowly eastward. A distinct angled lowering forms pic 1118 onwards which we believe to be a wall cloud and then a large scud lowering became visible pic 1135 onwards and appears to move left to right around what we believed at the time was a concentrated area of conversion and rotation. Soon after, a large sustained cone shape became visible but was not 100% definitive as a tornado due to poor visibility.
As you described, your attention is drawn to that sort of behaviour (if you know what to look for or you’ve seen it before) and our attention certainly was. Add to that these pics and damage path/s as well.
I think there is also evidence of an RFD cutting through and separating this circulation from the northern flank. I now theorize that a new collar organises pic 1193 to the north of the occluding cone circulation and has its own inflow from the east (we experienced ground level inflow from the east. Perhaps this new area then leads to the rotation and disturbance that is the dust vortices, regardless of how they are classified. Meanwhile the larger circulation is somewhat left behind but may be visible in the lower background of a few later shots of the extended vortice tubes.
Interested to hear your views.
Brad.
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Ok here are some pics re-posted with some brief annotation as to what I was seeing at the time and what I am seeing in the pics. I may be wrong so let me know what you think if I am.
Considering the sustained, defined cone shaped edges and low bases in the area of the confirmed damage path, apparent inflow features initially feeding in from the west and then later from the east and below and behind the other clouds, definate presence of RFD in the area of the circulation and another RFD later at our position, the lack of any outflow and the fact that dusty vortices were produced afterwards in my pics leads me to believe there was at least a tornado between Avenel and Locksley and that new areas of circulation responsible for the dust vortices built on the northern flank as it approached Longwood while RFD cut around and wrapped the tornadic circulation to the south.
Thats my conclusion.
Brad.
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and a few more shots showing both the close and wide views of these features:
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Hi Brad,
Nice work on the pics and descriptions. I can certainly picture what you're suggesting as far as a circulation in that region and like I said somewhere above, if you saw it, then it's real, you guys were certainly close enough.
Just two quick questions for now, one general the other a little technical (feel free to fire to Harald).
- First, are you guys sure the storm tops are only 5km? The ominous appearance of the bases suggests reasonably tall storm ( I suppose I mean at least say 8km. 5 km seems shallow)? Where did the five 5km come form?
- Second, is it possible to get a bona fide RFD (as opposed to FFD) without a mid-level mesocyclone. From my reading the RFD generally has its origins in the mid levels of a (supercell) storm, whether simply due to negative buoyancy or whether it is dynamically induced by the positive vertical pressure pertubation (ie is forced down rather than simply falls). Can these processes occur with shallow convection (ie 5km assumption here) and without a mid-level circulation?
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Hi David and thanks for the feedback.
Re the storm tops, the original advice provided by the BOM (I think) to John was tops of 5km or thereabouts. I don't know what data lead to this conclusion as I was not involved in the conversation. Since then I have read commentary from Clive Herbert that suggests he viewed the storms from the west and observed tops closer to 10km, accompanied by very active lightning that he believes was typical of a storm with higher tops than the originally suggested 5km. Further to this, I spoke with John Allen briefly and he advised that a recent discussion with Harald Richter concluded that the tops were most likely (at least) 8km which corresponds with your suggestion. Again, I dont know what data or analysis has been used. Hope that clarifies that for you and perhaps clears up some of the second part of the question regarding RFD and the need for mid-level meso. I will leave the more technical response to John if he can add anything but I do know he is having a minor op and may be offline for a bit.
Regards,
Brad.
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Ok Brad,
Since then I have read commentary from Clive Herbert that suggests he viewed the storms from the west and observed tops closer to 10km, accompanied by very active lightning that he believes was typical of a storm with higher tops than the originally suggested 5km. Further to this, I spoke with John Allen briefly and he advised that a recent discussion with Harald Richter concluded that the tops were most likely (at least) 8km which corresponds with your suggestion.
Great to see the discussion ongoing. Brad, ok have we moved away from the low topped situation <5km tops? How does that change the concept of low topped supercells being discussed in the early part of this topic as a compact saturated layer.
Regards,
Jimmy Deguara
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Ok Brad,
Great to see the discussion ongoing. Brad, ok have we moved away from the low topped situation <5km tops? How does that change the concept of low topped supercells being discussed in the early part of this topic as a compact saturated layer.
Regards,
Jimmy Deguara
Hi Jimmy, it seems that all info is pointing to tops that were higher than 5km so if that is the limit of the accepted definition (and I wouldnt know) then I guess it ends the discussion of low topped supercells in this case.
On another note i've reviewed all my pics and there are some absolute ripper structures, corkscrews and inflow features which I will post up when I can.
Brad
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Well I have been following this discussion for a while and found it quite interesting. Certainly a lot of dust getting kicked up in those photos. Whether that's a gustnado or a tornado is hard to tell from the photos. Certainly if there wasn't strong outflow pushing out from the storm and there was rotation up to the base of the storm that would support that it was a tornado. What ever it was, there is clearly some damage. Tornadoes can form in a surprisingly wide range of conditions and from rather ordinary storms (visual presentation on radar) so I am willing to have an open mind.
Going back to the first page of this tread, Michael Bath posted the Melbourne sounding from the morning. Regarding storm heights, shouldn't it be easy to have a rough guess based on local surface observations around the time of the storms? The tropopause was up around 12km so provided there was enough surface heating and lower-level moisture I see no reason that the storms should be low topped.
Michael
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I have a feeling the 5km came from radar echo heights (from 3D scans). If that is the case, it simply suggests that updrafts were not overly strong if that's the height to which the precip was being held aloft to (at that location at the time).
Clyve's reports of tops of 11-12km may not have coincided with the actual location of the above incidents.
I still think that there is some doubt over the feature in your photos Brad. Given the location (seems to be somewhat distant, making it difficult to discern rotation from general movement) and the conditions at the time (not condusive to strong convection), and the radar (also not condusive to tornadic storm behaviour), the conditions don't really stack up for a "wedge" tornado and I fear it may just be well shaped scud.
I also noted in the obs on the day that there was outflow gusting to 35knts at two locations in the North Central district as the area of storms past over. These are two very small localities which are no indication of the strength of outflow in other areas which may've been much stronger.
Again, this doesn't take anything away from the excitement of the chase and the quality of the post-event assessments and analysis.
Macca
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Hey Macca, I appreciate the logic and use of the obs you quote in coming to your explanation of the events but how do we account for the extensive length and width of the damage paths observed and documented by us (which is clearly not straight line wind damage) which correlates very well to where the features are shown in the pics in the area of Avenel? I'm really not concerned whether the concensus or personal views are tornado or not tornado, wedge or not wedge because we have no visual proof of a touch down in that location but more the point of what cloud feature could possibly have such a sustained and defined edge, particularly the left hand edge in one of the shots and also be present in the vicinity of such damage as we identified. Something had to cause the damage. Not sure you've seen the damage pics posted earlier or are convinced by them? We have many more if you're interested.
Also, it may be worth having a look at the doppler radar (Yarrawonga I think) for this event because there are several interesting strong (red) returns in the region that further add to the question of what happened that day. Obviously there are variables that need to be considered when looking at the doppler returns (and i'm no expert) and perhaps artifacts/errors could account for the sudden extreme returns that are shown, but so too could a tornadic circulation I guess. What do you think?
Oh and thanks for the comments about the chase and the post-event analysis.
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Interesting response John. The assumptions you mention that I have made about instability are based on fact. The assumption that you would bother to claim a tornado without sufficient evidence - this is personal opinon based on the evidence provided - has nothing to do with assumptions.
I'm not going to comment any further on this day - you've made your conclusions, I've made mine. They are different. What's unfortunate about yours though, is that it ends up in a national database which may then be used for various reasons (political, funding source, statistical, etc) and in that sense, without sufficient evidence, it should not go down as a tornado. As I said above, I don't believe there is sufficient evidence to call this a tornado.
End of discussion from me.
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In the end whether it was a tornado or not it doesnt affect me, the reason why I argue so vehementally is because of the evidence; physical, visual and meterological..that is all
Wow! What can I say but I only just survived reading through segments of this discussion. Talk about turning a mole hill into a mountain. Sorry to strongly disagree but you have no visual evidence of anything other that gustfront that is picking up dust. I've seen the same thing dowzens of times and never once thought there was a tornado at work. Weak is the only way I can describe the visual evidence. Weak and also un-interesting.
As for the physical evidence, what do you mean? Is there a tornadic damage path? Whereare those images?
Regards Jeff.
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Wow! What can I say but I only just survived reading through segments of this discussion. Talk about turning a mole hill into a mountain. Sorry to strongly disagree but you have no visual evidence of anything other that gustfront that is picking up dust. I've seen the same thing dowzens of times and never once thought there was a tornado at work. Weak is the only way I can describe the visual evidence. Weak and also un-interesting.
As for the physical evidence, what do you mean? Is there a tornadic damage path? Where are those images?
Regards Jeff.
Jeff, for reasons I have stated very clearly in this thread already I was not intending to discuss this event any further mainly due to the complete lack of response from many who have presented outright views (which is fine) but have failed to answer questions or address evidence presented from field obs, radar/doppler and meteorological put back at them to explain their reasoning. However, your post requires a response.
Firstly, I suggest if you are going to post in the manner you have that you read the whole thread first. To admit you havent read it all but post the comments you have are ignorant on this event at best in my opinion. There is more to this event than the dust pictures near Longwood that everyone seems so fixated on and that you have based your post on. Perhaps you could read through the whole topic and endeavour to answer some of the questions put to the forum by John and I.
At least half an hour prior to that 'uninteresting' feature emerging and picking up the dust, John and i were observing from one spot this storm exhibiting behaviour in the Avenel area that at the time I believed was potentially tornadic on visual observations alone. It certainly was not an outflow situation and in fact was clearly to us developing inflow features below the low base and developing a large cone shape with defined edges. There are images in the thread that show the features we saw at the time and high contrasting brings these out even more. And yes there are images of the significant (long and wide) damage path from Avenel to Locksley and I suggest you look at the summary on pg2 with a few accompanying pics (there are dozens more if you want them). Surveying last weekends storm activity north (likely tornadic) and south (100% straightline) of Shepparton has only served to reinforce my opinion that the damage from Avenel-Locksley was not straight line winds but NO ONE has provided an alternative explanation for this damage. As the storm moved eastward to our south, this area of our focus emerged and produced vorticies and dust.
Call it a mole hill if you like but this event was significant for a lot of reasons that have been discussed throughout the thread - tornado or not tornado. The dynamics on the day were incredible to see and I have been lucky enough to have chased many big days in the USA so I have some reference to make that call at least. There are many pics in the thread showing impressive storm features and structure (they all had rapid development) from many severe cells we chased before and after the Avenel-Longwood cell so this was no normal day, and hence deserved to be shared and discussed.
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Hi Brad,
Personally I, and possibly others, wish perhaps possible explanations on this event be forthcoming from you and John rather than asking us to provide possible explanations. You both have done damage surveys and have experienced the event - you were there - we weren't. From our perspective, we are simply suggesting possible explanations from the evidence provided to us based on images and what we think we are seeing based on our past experience. We may disagree on specific details but if you provide sufficient substantial evidence leading to specific features, then that will certainly go a long way to piece together the puzzle.
Whilst on the topic of damage surveys, I consider myself a beginner in assessing damage given I don't have an engineering background or many years of experience in damage surveys. Again considering Dunoon, despite making a damage assessment myself at the time, I confided with a professional at the Fort Worth NWS office for a second opinion. His assessment perfectly matched mine so for once I was correct!
To my knowledge, microbursts can produce eratic damage and gustnadoes as you saw in the US can spin up and move in a chaotic path along the gust front push. There really is unfortunately insufficient evidence either way.
Hopefully I have helped ease the frustration with the explanations here. I try myself to chat with a person other than myself as to their point of view prior to posting statements on this and other forums unless I am absolutely certain eg Dunoon. I have advocated for years on the various forums for storm chasers to use words like "possible", "probable" and "likely" when decribing tornadoes and supercells in particular. Great to see this is going to be adopted from here on.
Regards,
Jimmy Deguara
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Personally I, and possibly others, wish perhaps possible explanations on this event be forthcoming from you and John rather than asking us to provide possible explanations.
Hi Jimmy, I think what you're getting at is:
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In science, the burden of proof falls upon the claimant; and the more extraordinary a claim, the heavier is the burden of proof demanded. The true skeptic takes an agnostic position, one that says the claim is not proved rather than disproved. He asserts that the claimant has not borne the burden of proof and that science must continue to build its cognitive map of reality without incorporating the extraordinary claim as a new "fact." Since the true skeptic does not assert a claim, he has no burden to prove anything. He just goes on using the established theories of "conventional science" as usual. But if a critic asserts that there is evidence for disproof, that he has a negative hypothesis — saying, for instance, that a seeming psi result was actually due to an artifact — he is making a claim and therefore also has to bear a burden of proof.
* Marcello Truzzi, "On Pseudo-Skepticism" in Zetetic Scholar 12/13 (1987), pp3-4,
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I absolutely agree with what you have written.
A claim of a tornado by anyone, not necessarily John or Brad as in this case, does not in itself require any evidence. It reminds me of a chat with a winemaker the other day re the magical $100+/price bracket - you can sell your cheapest clean skin wine at $100.00, but the question is will anyone buy it? To back that price up you better have something special in the bottle.
I can say that I saw a tornado this afternoon, for example. The question is who will believe that claim. Initially, benefit of the doubt would apply. Once the dust settles, however, evidence in the form of imagery, and esp. video footage, is expected to be forth coming, dare I say required in for the claim(s) to be 'accepted' by the wider weather community.
The bottom line re this thread is that there is a disconnect between the reports and the photo evidence provided in the minds of those who were not there. The claims made have not been accepted as fact by the wider storm chasing community, largely because the features in the photos are far more suggestive of other (non-tornado) processes. I was going to say not accepted by the kangaroo court of our forum, but the bottom line is some very experienced people have made comment, who should be acknowledged, and their perspective thoughtfully considered.
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Jimmy and David,
I respect both your experience and opinions - always have and I would imagine always will. I also know or have briefly met others on this forum and elsewhere who I know and respect have much more experience than I - at least theoretically and most of them field chasing as well. I don’t need to be encouraged to thoughtfully listen to anyone I respect because I always do. Most of what I have experienced and learnt about severe weather (as little as it may be in the scheme of things) has its origins either in the US with Jimmy for weeks and weeks on end or on this forum and no doubt I'll add to that in the USA with you guys this year.
But, having said that my expectations of communication and information gathering and sharing on a forum are a 2-way street and clearly to me goes beyond the expectations that you guys are describing and well beyond the majority of posting that has occured on this topic thread unfortunately. It seems that you are advocating a situation where a claim is presented, some evidence (however flimsy or definite) put forward and then the claimant should accept any opinion put forward by others who have more experience without expecting or hoping for any discussion, explanation or sharing of the higher level of knowledge or experience of those who are not convinced.
I appreciate you are both explaining why we got the response we got but that doesn’t make it right. We don’t have a track record of false reporting observations but from the reaction of some, you would think we did. For what it’s worth (perhaps not much), I can tell you there are people on this forum who have intimated that they don’t agree with some of the opinions or methods of communication posted in this thread so we are not completely alone on this.
We claimed a tornado based on observing cloud to ground connection (ground level rotating rain curtains below a large funnel at Kilmore and later in the day vortices emanating from cloud and in contact with the ground). If we used the term tornado incorrectly after those observations then we have to be corrected but I don’t think anyone has corrected us on that. My understanding is that a even a gust front spin up is still a tornado (gustnado) if it is in contact with cloud and ground and that is what we saw. If the photos provided (and the video is just the same but shaky) are not conclusive for people to show contact that’s fine, of course! But to dismiss and not answer further questions (including about the larger circulation earlier than the dust) or clarify terminology or opinions in a forum? That is my beef.
Regarding us giving explanation for what occurred, I believe John (in particular) went to great lengths to provide his meteorological explanations for what may have occurred (including it seems to being open to the possibility that these storms did not necessarily follow conventional rules of behaviour) and for why some suggestions made on the forum simply don’t add up for all of what we observed and have reported. However, responding to the forum with this information didn’t garnish much discussion but instead appears to have annoyed and perhaps added to confusion.
On top of this technical explanation though, both John and I also put questions (some very technical and some on basic definitions and principals as I understood them) to individuals who made certain comments and to the forum at large after opinions were shared about our photos and what they did or did not show. Overwhelmingly these questions (some which were asked repeatedly) went unanswered. There was very little elaboration or sharing of thoughts or rationale as to why there was no tornado but mainly just the opinion that it wasn’t. We were dismissed and ignored by most on this forum. Simple as that and it’s a real shame.
It seems that most of our visual obs at the time (such as there was no outflow other than an apparent RFD from the right (west) of our position as we moved - only inflow at any time during our pics and for at least the short duration of our NE retreat on the Hume where we encountered inflow dust) and our obs during the damage survey, combined with advice to John (from the BOM and an independent expert on radar couplets/signatures) have been dismissed by the majority of members who have participated in the thread – fine because they’re akin to hearsay and I understand that. But surely it's not good enough to just post an opinion (based on a few photos alone) and not respond to a reasonable question that is seeking to understand the basis of the opinion or clear up what we (or I) think ‘may’ be a contradiction or misuse of a term that was used. I don’t accept this. I am not an expert on any of this but I am entitled to ask a question and expect a reply so I can at least learn. This message does not seem to be getting through, hence when I read today’s posts I feel obliged to respond again.
Sorry for rambling and repeating but I felt it necessary. I don’t intend to discuss this on the forum again.
BTW Hopefully you will all be impressed by the pics and video we will share from the recent events in southern NSW and NC Victoria.
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Brad,
I honestly think you have done well in putting forward all the issues from what you saw. I also live in VIC and think that there are many times people reject or ignore what gets put forth about storms from this State, and willingly share your frustration.
As one who also has observed storms from an ametuer level (I'm in no way an expert in storms - still a student in learning), but from what I saw of the pictures, and from own personal experience and observation on storms in VIC, I am truly thankful for having someone else from here discuss storms well, and put forth opinions and thoughts extremely well. For that I commend both you and John Allen. Between you both, I have learnt much about storms here, and to Jimmy's insight and willingness also to teach me about structures and storm behaviour, my knowledge on storms is better now than it was in 1983, when I saw my first ever tornado (shortlived though it was).
Please, to all "experts" on this forum, please feel free to answer the questions that we amatuers and novices do ask, otherwise we have no way of really proving our understanding and improving our knowledge of storm structure and behaviour. We need more input from those in the know, and not just plain dismissals and rejections....
That is my two cents!
Now... back to the storms....
The storm, although not the typical severe storm that hit Melbourne and surrounds on 7th March 2010, did however have a familiar path trait for most extreme severe storms here - it is normal for these storms to track from NW to SE - recent storms like the 2004 EF0 tornado that blasted Sunbury and associated storm that followed a freeway path to Dandenong before dying out... the 2005 intense low pressure cell that converged on central VIC then followed SE path to the Tasman, and even this current storm went from NW Suburbs dumping extreme rain through Flemington Racecourse, then ending up in Ferntree Gully - another SE path...
For anyone who knows storms in the Southern Hemisphere, is this a normal observation? or am I just on another wild goose chase?
Peter J
(ps waiting for the next storm - may end up being remnants of STC Ului when she heads south!)
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It seems that you are advocating a situation where a claim is presented, some evidence (however flimsy or definite) put forward and then the claimant should accept any opinion put forward by others who have more experience without expecting or hoping for any discussion, explanation or sharing of the higher level of knowledge or experience of those who are not convinced.
Hi Brad, just to finish up too, thanks for posting your thoughts.
As I think I mentioned earlier if you guys saw the rotation and the vortex satisfied the widely accepted definition of a tornado, then clearly that is what you saw, and I'll take your word. So the issue is with the interpretation of the pics and whilst you guys probably mentally associate those pics as part of the broader dynamic convective scene that you witnsessed, my view, and that of others, is limited solely to the photos, which 'unfortunately' are not convincing. Visuals or 'ground truth' are the direct evidence here. I realise that John has posted lots of good supporting stuff. I tend to consider damage tracks (except the blatantly obvious), radar signatures in such non-obvious (other than typical tornadogenesis cascade paradigm) cases as circumstantial evidence as it requires one or more deductions to be made. In the case of including damage as evidence of a particular tornado having occurred we must assume that the damage was tornadic, and if it was, that the damage was caused by the tornadoes that you saw. Tornado damage assessments are not trivial, as Jimmy eluded to above. For that reason, such circumstantial evidence can be used to put together a hypothesis, but certainly not as definitive evidence of a tornado having occurred. Ideally, without a DOW sitting in a field next to you, I would like to see a video showing your funnels spinning and all the dust twirling. You have said that that is what was happening; I hardly think that either of you two are lying, you are pretty close, so I believe that. I do think we could all consider setting up a John and Brad camcorder fund raiser to make sure this is the last time such events go unrecorded!
It might all sound academic, but I think the 'scientifically-minded' storm chasers, as most of us are here, need to try and adhere to certain standards in storm reporting and documentation, wherever possible. Again not saying you guys have not done that, but more generally, as there have been significant issues in the past with accusations of photoshop jobs and the like here in Australia. It must also be considered that many chasers in their exuberance of being under a violent storm see lots of motion etc (not you guys, this is a blanket statement) add 1 (clouds) and 1 (motion) and get 3 (tornado). ie Corop 'tornado' was an example where I simply cannot see any tornado or any low-level meso with the video, as spectacular as those storms were. This forum was basically created for that purpose - more rigorous and accountable storm reporting.
We claimed a tornado based on observing cloud to ground connection (ground level rotating rain curtains below a large funnel at Kilmore and later in the day vortices emanating from cloud and in contact with the ground). If we used the term tornado incorrectly after those observations then we have to be corrected but I don’t think anyone has corrected us on that.
As answered above not doubting what you saw, but video would have been great. The pics simply do not convey that dynamism, at least from my perspective. At the end of the day it is probably equally as disatisfying being the chaser (and to be questioned over what you know you saw) as it is being the doubting thomas in not being able to see what the chaser might have seen.
Regarding us giving explanation for what occurred, I believe John (in particular) went to great lengths to provide his meteorological explanations for what may have occurred (including it seems to being open to the possibility that these storms did not necessarily follow conventional rules of behaviour) and for why some suggestions made on the forum simply don’t add up for all of what we observed and have reported. However, responding to the forum with this information didn’t garnish much discussion but instead appears to have annoyed and perhaps added to confusion.
I definitely think there has been some confusion along the way on the nature of the convection low-topped or not, whether the tornadoes where mesocyclonic or gust front tornadoes, or something els etc. That's all fine, but I agree this has probably added to the confusion.
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Hi David, I know I said I wasnt discussing this anymore but I wanted to acknowledge your comments and clarify that I also had noted your earlier comments re what we saw so thanks. Your camera fund comments made me laugh, and although I need a new cam simply because mine has seen 4 US trips! my main problem was no tripod for video on the day so perhaps a tripod fund would be better! ;D
And Pete, thanks for your 2 cents and kind comments. I would be shocked but flattered if anyone has learnt anything from me so thanks.
Regards,
Brad.