Storm Australian Severe Weather Forum
Severe Weather Discussion => Australian Severe Storms, Weather Events and Storm Chasing => Topic started by: Antonio (stormboy) on 30 October 2009, 11:08:22 AM
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Hey guys yes I know that I have started this topic a little early but have any of you looked through the latest Cape maps? Well if not you will notice that the attached one below has more colour than I have ever seen on a Cape map of NSW usually I see these colours in Darwin region.
So I have come to the conclusion that there might be a possibility of some potentially severe thunderstorms possibly in the Grafton area as well as the northern tablelands. Thunderstorms are also forecast for Tuesday but the cape is not that great.
storm boy
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Ok just had a check on BSCH and the maps of Thursday and Friday are also showing instability at a huge level.
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Well folks the BSCH Cape chart has gone down for today’s forecast but Thursday looks to be very promising in the western parts of the northern rivers and also the whole of the northern table lands looks like it will have something good to develop over them. The forecast shows thunder possible right till Friday even Saturday so that will be good.
storm boy
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Hey
I have been looking at the cape for tommorrow and looks promising with high cape levels for warwick-beaudesert QLD and I am most likely going to go to Warick or somewhere near there tommorow.
I was Just wanting to know what everyone else will be doing tommorrow and if I am heading to the right place as this is my 1st time.
Clayton
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Hey Clayton
My 1st proper time tomorrow as well, and I think I'll be heading near Wawrick also, looks like its going to be bloody good day! Right where that area of high CAPE is, there is also a bullseye of about 175mm accumulated precipitation!
Keep an eye for silver Mitsubishi Pajero with some guy aiming his camera at the sky!
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I too am looking forward to tomorrow. In my mind, it is actually looking better for SE Qld than a few days ago when it looked like most of the action would be further south. There are a few things I like about this setup but a few things that concern me too.
Pros- Potential for high CAPE - dew points are in the 18C-20C range along the SE Qld coast. If we get temps in the high 20's to low 30's with dp in the high teens we could get CAPE > 2000 j/kg. Potential triple point at the surface and nice deep NE'ly low level flow.
Cons- Moisture is quite shallow at the moment. Despite the high dp's along the coast, it dries out pretty quickly heading west. This is usually indicative that the moist layer is pretty shallow. Last nights Brisbane sounding supports this where only the lowest 50 mbar was moist. Finally, mid and upper level flow is weak.
I am hoping that moisture depth improves tomorrow and that a combination of high CAPE and a favourable surface feature can make up for the weak shear. Fingers crossed.
Michael
Edit: I will say one thing, don't but too much faith in those GFS CAPE charts. They can be way off sometime. A few times this year GFS has forecast CAPE > 4000 for the NSW southern tablelands due to over doing the surface dew points. Conversely, GFS may have low forecast CAPE due to forecasting low surface temps when in reality 30C is likely.
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Hey Dan and Clayton,
Michael T virtually took the words outta my mouth. Warwick and further south look pretty good tomorrow but the shear is only just passable. Going by the forecast sounding for my area tomorrow at 06z it looks like it has better moisture to play with (I use these as a guide only as they are quite smoothed compared to the BoM soundings). Tomorrow mornings Bris sounding should give a better indication of what the day holds. As there has been stuff all in terms of storms here this season I'll be hoping something does fire because I'm starting to get a bit desperate :p. I'll be chasing locally around the Casino-Kyogle-Lismore area. Good Luck tomorrow guys....I reckon the first chase is always the hardest! Follow your instincts and have fun but as always be safe. Hope you bag a good one!!!
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Nice storm just formed near here with some spits of rain. Theres one nasty cell heading towards Taree in southeasterly direction! No sure if thats a supercell yet with severity looks on the radar.
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Hey
It looks as if the main Point of Interest has moved slightly south back to near casino-tenterfield by looking at the cape, moisture and LI charts
So I am unsure as wear to head but it looks as if the high cape area is moving northward during the day but I may be reading the charts a little to early.
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Hi all,
Looks nice for NE NSW and SEQ today. Shear is lacking but what is lacking in that department will be made up for by some pretty decent levels of instability.
Its an interesting set up with dry air pushing in through much of the area north of Brisbane, however, the SEly change that moved through NSW yesterday pushed inland far enough overnight to moisten the lower levels over NE NSW and the southern half of the SEQ area. With DP's on the ranges now being up in the mid-teens, it shows that the moisture depth is at least 1000m deep and I've been following the models and obs closely over the last 24 hours and I think the models have a good handle on the moisture situation - so I'm not as concerned with moisture as I could've been.
As has been mentioned, shear is somewhat lacking. 500mb winds are around 25knts (maybe up to 30knts) from the WNW and 700mb winds are in the 15-20knt range from the NW. The anvils will be being pushed along by a 35-50knt jet (depending on how high the storms get...but based on the soundings, I'd suggest this will be around 40-45kft). Of interest is the shear later on in the lower levels - it is forecast to pick up to 15-20knts from the NE (or even ENE) at 850mb which could make things slightly more interesting.
Instability is quite nice with 500mb temps of -14 and DP's well into the teens we should see MLCAPE of around 2500jkg and LI's of between -6 and -9. Given this level of instability and the moderate shear, I'd suggest flash flooding and the potential for some very large hail are the two main features today (although damaging winds are often a factor on days like today as big downbursts occur). Hail size has the potential to get up into the 6+cm range in the strongest storms today (it reminds me quite a lot of Nov 8 2006 where I lost my windscreen near Esk to 8.5cm hail).
I think storms will go up along the ranges today as well as along the dry/moist air boundary which is sitting further west and are likely to move ESE initially before heading NE as they reach severe levels. I think anywhere from Grafton to Toowoomba could be a target for chasers out there today (although more cloud further S) but for anyone heading out for a first time, take care out there today - it should get pretty nasty :) :). Personally I like the Warwick - Tenterfield - Texas triangle.
Macca
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November 4'th 2009
I went out last night and photographed some nice lighting, the storms were moisture starved but had plenty of nice lighting, I love those storms at night the cg's are long and there's not much rain in your way..I'm absolutley spewing I have to work from 2-5pm today! i'd be chasing Grafton and just north for sure the instabilty looks great :o My bet is a severe storms moves through this area this arvo with big hail.. Pics from last night:
(http://i27.photobucket.com/albums/c172/enak12/November%204%202009/IMG_8680copysmall.jpg)
(http://i27.photobucket.com/albums/c172/enak12/November%204%202009/IMG_8682copysmall.jpg)
(http://i27.photobucket.com/albums/c172/enak12/November%204%202009/IMG_8692copysmall.jpg)
(http://i27.photobucket.com/albums/c172/enak12/November%204%202009/IMG_8695copysmall.jpg)
(http://i27.photobucket.com/albums/c172/enak12/November%204%202009/IMG_8683copysmall.jpg)
(http://i27.photobucket.com/albums/c172/enak12/November%204%202009/IMG_8696copysmall.jpg)
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Hey
I've had a change of plans due to the latest cape and LI charts and I am most likely going to head down to casino-woodenbong-tenterfield area as the cape has moved south.
I was wondering if anyone else had the same idea or had different plans. Also if I am heading to the right place.
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Looking interesting here at Armidale today. Its insanely hot and humid with plenty brewing convection in skies. Lots of RFB's and Cumulonimbus with stratas mixed. Yesterday we had a bit of rain from atomic bomb severe cell formed just north of here and our max temperature was 31 degrees! Today isa bit cooler but around 25 as to be the maximum with high dewpoints which is good sign.
I wont be surprised for atomic bomb convection today again!
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Atomic bomb cells firing up with some severe cells near here and Tenterfield yet some more under convection on Moree Plains and Slopes. Severe Thunderstorm Warning is out now.
TOP PRIORITY FOR IMMEDIATE BROADCAST
SEVERE THUNDERSTORM WARNING
for FLASH FLOODING, LARGE HAILSTONES and DAMAGING WIND
For people in the
NORTHERN TABLELANDS and parts of the
NORTHERN RIVERS and
MID NORTH COAST Forecast Districts.
Issued at 1:26 pm Thursday, 5 November 2009.
Severe thunderstorms are likely to produce very heavy rainfall, flash flooding, large hailstones and damaging winds in the warning area over the next several hours. Locations which may be affected include Grafton, Tenterfield and Dorrigo.
Interesting afternoon and evening for us. Its raining here moderately under convective cells. Smell lovely after the stinking hot morning.
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Some pretty intense looking cells over Northern NSW on the radar this afternoon. There have been reports of hail at Stanthorpe from the storm that has passed through the area, just waiting for verification.
Cells are currently building in SEQ just east of Oakey ( 1.44pm QLD time).
Col
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They don't seem to be moving very much at all. For coastal areas, I wouldn't be holding my breath over this one.
But still, it looks very good (or very bad if you're near or under the Allora monster ATM).
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Location Warwick SE QLD 5/11/09
OMG..the storm that just left here was incredible, I'm still shaking but going to see if I can catch the back end of it! I'll post photos later when I settle a bit but it's one hell of a storm!!
Regards,
Chris.
Bureau of Meteorology
Queensland Regional Office
TOP PRIORITY FOR IMMEDIATE BROADCAST
SEVERE THUNDERSTORM WARNING - SOUTHEAST QUEENSLAND
for DAMAGING WIND, FLASH FLOODING and LARGE HAILSTONES
For people in parts of the LOCKYER VALLEY, IPSWICH CITY, SOUTHERN DOWNS, SCENIC RIM and TOOWOOMBA Council Areas.
Issued at 4:05 pm Thursday, 5 November 2009.
The Bureau of Meteorology warns that, at 4:05 pm, very dangerous thunderstorms were detected on weather radar near the area north of Warwick and Allora. Thunderstorms are moving towards the northeast. Very dangerous thunderstorms are forecast to affect Aratula and Clifton by 5:05 pm.
They are forecast to affect Boonah by 4:35 pm and the area between Boonah and Beaudesert by 5:05 pm.
Damaging winds, very heavy rainfall, flash flooding and large hailstones are likely.
7cm hail has been reported east northeast of Warwick at 3:40pm.
Golf ball size has been reported at Allora at 4:00pm.
Marble sized hail was earlier reported at Stanthorpe at 1:40pm.
Emergency Management Queensland advises that people should:
* Move your car under cover or away from trees.
* Secure loose outdoor items.
* Avoid driving, walking or riding through flood waters.
* Seek shelter, preferably indoors and never under trees.
* Avoid using the telephone during a thunderstorm.
* Beware of fallen trees and powerlines.
* For emergency assistance contact the SES on 132 500.
The next warning is due to be issued by 5:05 pm.
A more general severe thunderstorm warning is also current for parts of the Wide Bay and Burnett, Darling Downs and Granite Belt and Southeast Coast districts.
Warnings are also available through TV and Radio broadcasts, the Bureau's website at www.bom.gov.au (http://www.bom.gov.au) or call 1300 659 219. The Bureau and Emergency Management Queensland would appreciate warnings being broadcast regularly.
(http://farm4.static.flickr.com/3431/4076625985_31bf45b974_o.jpg)
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That cell currently west of Boonah looks very very nasty indeed on the radar.
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It has been an interesting afternoon with the explosion of cells through out Southern QLD. It is well worth a look at the archived radar for this afternoons events, especially with the cells that formed over Warwick and Boonah, they defied the trend and made an northerly track, that being the opposite of the main cluster of storms that were moving to the south east.
One chaser reported hail in Stanthorpe this afternoon. ( waiting for verification of the size, some exaggerated sizes have emerged from various sources)
The storms cells appear to be merging and should now form a rain band in which I would expect thundery rain to make its way over Brisbane this evening.
Col
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Storm warnings have been in place throughtout the afternoon and continue so this evening. Thunder and lightning can be seen and heard to the west of me.
Current storm warning from BOM
issued at 6:04 pm Thursday, 5 November 2009.
The Bureau of Meteorology warns that, at 6:05 pm, severe thunderstorms were detected on weather radar near Yarraman, the area northwest of Cunninghams Gap, the area south of Helidon and the area north of Cooyar.
These thunderstorms are moving towards the east to northeast.
They are forecast to affect Gatton, Rosevale, Mulgowie, Blackbutt and Nanango by 6:35 pm and Laidley, Grandchester, Moore, Linville, the area east of Nanango and the area north of Nanango by 7:05 pm.
Damaging winds, very heavy rainfall, flash flooding and large hailstones are likely.
7cm hail was reported east northeast of Warwick (near Freestone) at 3:40pm.
Golf ball size hail was reported at Allora at 4:00pm.
Marble size hail was reported at Stanthorpe at 1:40pm.
Emergency Management Queensland advises that people should:
* Move your car under cover or away from trees.
* Secure loose outdoor items.
* Avoid driving, walking or riding through flood waters.
* Seek shelter, preferably indoors and never under trees.
* Avoid using the telephone during a thunderstorm.
* Beware of fallen trees and powerlines.
As I stated in the previous post, reports of hail have emerged, the BOM is now stating that
7cm hail was reported east northeast of Warwick (near Freestone) at 3:40pm.
Golf ball size hail was reported at Allora at 4:00pm.
Someone stated that around Stanthorpe there was hail around the 6CM mark where as BOM have reports of Marble size hail was reported at Stanthorpe at 1:40pm..
Be interesting to see full reports as these cells move through.
Col
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As I stated in the previous post, reports of hail have emerged, the BOM is now stating that
7cm hail was reported east northeast of Warwick (near Freestone) at 3:40pm.
Golf ball size hail was reported at Allora at 4:00pm.
That hail report was from James Harris and myself. 7cm is probably about right but there looks like (on the video) that there may've been a few bigger ones - it was pretty huge and most cars lost windows - somehow I didn't. More details from the chase later - hopefully with pics.
Macca
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Hey
I ended up having to go to school (mum winged) and then after managed to catch the cell that developed over by Boonah in the afternoon.
There was some nice formation and hail dropped and was about 3-4cm directly over the town. Great storm with some excellent lightning
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I can't post 2 pics at the same time it won't work so here is another
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I was just reading the opinions on the storm at the weatherzone forums and looks like I missed out on most of the boonah storm as they said it intensified again
after I left which was about 30min (my picture is in NSW time) DAMN!! I had no radar and was just going by gut feeling and also my mum was annoyed and wanted to go home
(on my Learners). Hope someone else can post some pics of what I missed.
It was an ok 1st time and probably lucky I didn't get in something big with no radar.
Clayton
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Ok so after my post this morning, I headed off to my target area (Warwick - Tenterfield - Texas). I made it as far as Warwick before a big storm exploded to the south near Tenterfield. With more storms exploding (literally) around Stanthorpe and the Tenterfield cell moving N, I hung around there and got some nice photos as the cells merged and put on a nice display of inflow/outflow interaction near Dalveen (N of Stanthorpe). I met up with James H near Stanthorpe and we chased the rest of the day together. We were a little put off by the big outflow push near Dalveen and we slowly moved northwards towards Warwick. It was as we neared here that we saw a new storm developing just to the east of there so we took a short cut around the south side of Warwick and popped out under the base of the now 40kft+ storm. We encountered some smallish (1-3cm) hail to start with and we quickly worked out the storm was hardly moving so we just stayed in the hail to play with it. We also had a great view of the base which was just 1km to our north (and extended off to the west - it was quite large). Eventually we had to move slightly north and we ended up jogging north over the next 15-20mins in the hail moving about 1km each time to get back to the edge of the hail core between that and the base. During this time a very nice wall cloud had developed under the base just in front of us too and was being fed by some nice strong easterly inflow. Each time we moved N, the hail got slightly bigger (as the storm intensified). As we neared Freestone, the hail got up to 4-5cm and was making some LARGE thuds on the car. Eventually we had to move further N again and as we neared the intersection with the Cunninham Highway things got nasty. The hail started to get really big and James lost a rear passenger window and a tail light so he took off east. I stayed a bit longer to get some photos and footage of the hail and boy was it big. Stones in the 6-7cm range with some looking like they were probably up to 8cm. Cars and trucks were getting smashed windows all over the place and eventually I bailed east as well (somehow with my windows intact!). We stopped about 5km east of the storm and were treated to a barrage of close CGs with the base in the background. After a while we decided to head back towards Brisbane as going back through the core to continue the chase wasn't really an option. W got some more photos as the storms moved off the ranges but nothing as good as the early stuff!
Pics here...http://macca.bsch.au.com/gallery2/v/Season+09/November/ (http://macca.bsch.au.com/gallery2/v/Season+09/November/)
Macca
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Shows over. Looks like the southeasters have penetrated the coastline as showers are coming onshore. Funny how there appears to be some rotation on radar. Has anybody noticed this? Is that an upper low?
Good job to those who chased. 7cm hail is incredible.
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Clayton - great you were able to get amongst it - even if your mum did get sick of it. I know it is hard for people not into weather as they get bored pretty quick. btw - you can modify your post and attach additional photos (there is a forum bug).
Macca/James - you got your storm and hail fix there !!! It looked evil enough on radar without even seeing it. Glad you were there to share some of it with us.
Some storms finally made it here (Mcleans Ridges) approaching 1am (EDT) with a lot of in-cloud lightning and 14mm over an hour. But nothing too exciting.
Look forward to your report Chris.
MB
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Macca, I would love to have been around the Warwick area with the huge cell that turned ( the main cluster of storms appeared to be travelling in a south east direction) and started to head in a North/ northeast direction and then merge with the cell over Pittsworth area.
It was impressive just to see it explode and watch it move on the radar. Was there any rotational movement in the cells around Stanthorpe and Warwick?
I had heard from other sources of large hail and of cars windows being smashed but I did not realise it was yourself and James reporting in.
Would have been a great chase.
Cheers
Col
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A few photos from yesterday. Sensational storm day and certainly brought my working day to an end!
(http://sydneystormchasers.com/system/files/images/09-11-05-01jh.thumbnail.jpg) (http://sydneystormchasers.com/system/files/images/09-11-05-01jh.jpg)
(http://sydneystormchasers.com/system/files/images/09-11-05-02jh.thumbnail.jpg) (http://sydneystormchasers.com/system/files/images/09-11-05-02jh.jpg)
(http://sydneystormchasers.com/system/files/images/09-11-05-03jh.thumbnail.jpg) (http://sydneystormchasers.com/system/files/images/09-11-05-03jh.jpg)
(http://sydneystormchasers.com/system/files/images/09-11-05-04jh.thumbnail.jpg) (http://sydneystormchasers.com/system/files/images/09-11-05-04jh.jpg)
(http://sydneystormchasers.com/system/files/images/09-11-05-05jh.thumbnail.jpg) (http://sydneystormchasers.com/system/files/images/09-11-05-05jh.jpg)
(http://sydneystormchasers.com/system/files/images/09-11-05-06jh.thumbnail.jpg) (http://sydneystormchasers.com/system/files/images/09-11-05-06jh.jpg)
(http://sydneystormchasers.com/system/files/images/09-11-05-07jh.thumbnail.jpg) (http://sydneystormchasers.com/system/files/images/09-11-05-07jh.jpg)
(http://sydneystormchasers.com/system/files/images/09-11-05-08jh.thumbnail.jpg) (http://sydneystormchasers.com/system/files/images/09-11-05-08jh.jpg)
(http://sydneystormchasers.com/system/files/images/09-11-05-09jh.thumbnail.jpg) (http://sydneystormchasers.com/system/files/images/09-11-05-09jh.jpg)
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A few photos from yesterday. Sensational storm day and certainly brought my working day to an end!
That's a great looking storm there James and Macca. Looks like you could just reach up and touch that wall cloud! It also shows what contribution a solid 'backed' low level flow can make despite the overall rather slack winds higher up (chaser speak here, ie 'backed' meaning easterly component!).
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Nice shots, and looks like you a buzz of a chase James and Macca. Know someone who's off to fix dents & sounds like you might need it!
Radar interaction looked interesting, though there doesn't appear to be much defined onscreen rotation on the Doppler,
Interesting contrast at the Nth edge of the Cell that was NE of Dalveen at 3:55 UTC-4:19UTC
Cheers
Paul
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Raining away here at Armidale. Got alot cooler and temperatures only at 14.5 degrees now. It will be one of last weeks for me staying here!
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Had regular thunder and lightning for the past 2 hours here. Some visible CGs amongst it with very loud booming thunder. Must be originating quite high up. Slow moving cells from generally the NE but not a lot of rain so far.
Any more hail pics James, or damage ??? :)
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Michael - I see on the radar at the moment the general rainfall pattern is moving in a southeasterly direction. However the bigger storm north of Jackadgery is bucking the trend and pushing NW. There is also a stationary one at Wooli and a couple off the coast further south that appear to be forming and moving against the general flow as well.
I am guessing there must be quite a bit of shear up there at the moment, though it doesn't look that obvious on the latest Brisbane or Moree soundings.
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I was heading for Toowoomba/Warwrick but came across some sweet convection west of Kilcoy-Esk, so regrettably hung around there for the day. Although I saw some good storms, nothing compared to the beast's down south, I have learned my lesson though! Was worth the 500km I put in.
For my 1st real chase it wasn't bad, as I have said, many lesson's learned and look forward to applying them all next time to make for a better chase. Here's a few pics anyway.
Somewhere between Esk and Kilcoy
(http://i307.photobucket.com/albums/nn307/DanTheReptileMan/3.jpg)
This one was taken just north of Blackbutt, some strong winds and intense lightning there, my phone crapped out as I spilled coke on it and had no radar, but managed to talk to Dad who got the radar up and told me a black core was heading for Blackbutt, but then it stalled and lost it a bit, should have driven west but couldn't find any decent roads heading the right direction.
(http://i307.photobucket.com/albums/nn307/DanTheReptileMan/5.jpg)
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Location Warwick QLD 5/11/09
Hi, some images below as promised and it was quite an afternoon here in Warwick! Between the break in low level cloud you could see the massive towers forming directly above Warwick. This merged with a cell from the South and all hell broke loose.
I tried to stay on the southern side of it but found myself directly under it. I headed out Freestone Road (I must have been just behind Macca and James) and could see what lay ahead so I decided not to take the risk and went up to Mt Tabor instead, this turned out to be equally as dangerous.
To say this storm exploded is an understatement, I've never experienced anything like it.
There have been some serious fires in the region and the smoke is visible in the images, gives them an eerie cast as well.
Storms combining directly above Warwick. 15.16
(http://farm3.static.flickr.com/2449/4080644461_bec1145e87_o.jpg)
This one is taken in Warwick CBD at 15.33, looking up the face of the cell moving slowly towards Allora.
(http://farm4.static.flickr.com/3460/4081495760_11dfe5a0fa_o.jpg)
In position on the North Side of Mt Tabor looking towards Freestone, Cunninghams Gap and the battering they were copping at that moment 15.33
(http://farm3.static.flickr.com/2789/4080734935_12cf03a555_o.jpg)
This base formed in half an hour of the shot above and it was trowing out CG'S every few minutes with wide spread CC lightning. 16.01
(http://farm3.static.flickr.com/2673/4080735223_89bdf413cb_o.jpg)
Double strike over Freestone looking N/E 16.02
(http://farm4.static.flickr.com/3473/4081499126_93e4a9abe7_o.jpg)
looking N/W as the storm exploded and lashed Allora. 16.08
(http://farm3.static.flickr.com/2518/4080737509_e8a33cb366_o.jpg)
I was keeping an eye out what was happening behind me and it suddenly changed for the worse. I quickly packed up and I was down the side of Mt Tabor so had to get back to the top. As a Keen photographer I couldn't stop taking photos so was stopping every few steps to take photos.
This one looking S/W and directly over Warwick. 16.08
(http://farm4.static.flickr.com/3531/4081496662_2bafcb2f21_o.jpg)
Looking directly South the outflow at this point was unbelievable and at 110kg it was pushing me sideways and stinging pea size hail. 16.09
(http://farm3.static.flickr.com/2508/4081498426_26ee88ec73_o.jpg)
Turning around and looking again towards Allora to the N/W. 16.10
(http://farm3.static.flickr.com/2675/4080736907_9898d83921_o.jpg)
I knew I should not be where I was in the open so I headed for the Car. This one taken on top of Mt Tabor looking to the S/E and it was green! 16.13
(http://farm3.static.flickr.com/2795/4081497740_c014c12a53_o.jpg)
One final shot from the top of Tabor looking towards Allora again. 16.13
(http://farm3.static.flickr.com/2647/4081497384_e4f5bc4b8b_o.jpg)
And last shot looking NE over Freestone. 16.14
(http://farm3.static.flickr.com/2474/4081499536_9f3bac6e69_o.jpg)
Despite the damage the rain was beautiful for hours after wards and amazing amount of lightning.
Regards,
Chris.
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Thanks for that report Chris. Wish I could have been up there to enjoy it too.
Apart from the thunderstorms this system has brought very heavy rainfall again to parts of the Mid North Coast. 36-48 hour accumulations to 9am today (7 Nov) have exceeded 500mm at some centres. The heaviest falls have been in Coffs Harbour.
There are ongoing flood warnings current for the Orara, Nambucca, Bellinger rivers, and also Coffs Creek. A flood watch is current for the Hastings and Macleay rivers.
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Brisbane soundings for 5th November. The profile on the morning was impressive with significant instability up to 200 hPa and dry air aloft. All it needed was a boost in low level moisture and shear which occurred from the SE.
(http://australiasevereweather.com/storm_news/2009/thumbs/2009110500brisbane.png) (http://australiasevereweather.com/storm_news/2009/soundings/2009110500brisbane.png) (http://australiasevereweather.com/storm_news/2009/thumbs/2009110512brisbane.png) (http://australiasevereweather.com/storm_news/2009/soundings/2009110512brisbane.png)
128km Radar Loop for Brisbane, 02:00 05/11/2009 to 15:00 05/11/2009 UTC
(http://www.theweatherchaser.com/radar-thumb/IDR663/2009-11-05-02/2009-11-05-15/300.s.png) (http://www.theweatherchaser.com/radar-loop/IDR663-brisbane/2009-11-05-02/2009-11-05-15)
See : 256km Radar Loop for Brisbane, 01:00 05/11/2009 to 15:00 05/11/2009 UTC
(http://www.theweatherchaser.com/radar-thumb/IDR662/2009-11-05-01/2009-11-05-15/300.s.png) (http://www.theweatherchaser.com/radar-loop/IDR662-brisbane/2009-11-05-01/2009-11-05-15)
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Thanks for that report Chris. Wish I could have been up there to enjoy it too.
Thanks MB, I am sure you would have enjoyed it immensely!
Thanks also for the readings, have got a better understanding of them now studying your thread Aerological Diagrams.
http://www.australiasevereweather.com/forum/general-weather-all-topics-that-are-not-current-severe-weather-should-be-posted-here/understanding-aerological-diagrams-soundings/ (http://www.australiasevereweather.com/forum/general-weather-all-topics-that-are-not-current-severe-weather-should-be-posted-here/understanding-aerological-diagrams-soundings/)
Regards,
Chris.
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A few interesting things about that Freestone storm (let's call it that for now). When James and I were chasing further south earlier there was a strong outflow push from the earlier Tenterfield - Stanthorpe storm. This was concerning as it was heading north and it was quite strong. BUT...when we were just south of Warwick. You can see in the radar animation there were two little cells which fired up - one near Oakington and another near Killarney. The Killarney cell looked quite nice for a short while (shape on radar and visually) but it was undercut by the northward advancing outflow.
Another short while later, the Oakington Cell dissipated and the Freestone cell kicked off right on the outflow boundary (which was aligned east/west). It stalled in this region - I suspect due to the strengthening ENE'ly flow pushing into it. The storm then sits on this boundary for a LONG time after initiation (even after Allora gets nailed). You can still make out the boundary in the 6:06UTC image with the Allora cell on the western edge of the frame and the Freestone cell still sitting there NE of Warwick. Its not until just after that that another cell goes up in front of it, somewhat ruining the boundary interaction/storm development.
Certainly a very impressive set up. As has been mentioned, hail was definitely on the cards. You pretty much cannot rule out large hail on days where instability is as good as it was on Thursday - shear or no shear. Even if there was zero shear, there was enough instability to generate severe hail (>2cm). Add in 20-25knts at 500mb and the potential hail size increases significantly. Add in 20knts at the surface and it goes up again. Personally, I believe lower end shear events (such as this) in Australia generate larger hail than higher shear events. This is partly due to the higher shear events often occuring outside the "normal" storm season where moisture is often lacking (and hence instability). With the lower end shear events, the updraft is displaced just enough to get the hail to fall back into the region where it may get caught up in the updraft again for another growth cycle. In higher shear events, this tends to be more difficult because the updraft is too displaced to get the hail to fall into a "recycle" region. (There are exceptions to the above - if you have a high shear event with very strong instability, the updrafts will often stand up more vertically than the shear would normally allow and this is where the gorilla hail comes from...hehe).
Thursday's Freestone storm was a perfect example where the hail was just falling back into the updraft region and getting recycled several times. When we first encountered the hail it was early in the storm's life and was only in the 1-3cm range (guessing around the 5:00-5:12UTC images on radar). 10 mins later it had been through another cycle and was producing 4-5cm hail (guessing around the 5:18-5:24UTC images on radar). 15 mins later it had gone through another cycle and the hail size got into the 6-8cm range (around the 5:36-5:54UTC images on radar).
GFS appeared to nail this set up almost perfectly. Instability wise, shear wise, and precip wise. Pretty much right on it. It even picked up the boundary mentioned above.
Definitely a fantastic chase - I'd rate this in my top 3 chase days in Australia.
Hopefully I'll be able to get some more video up in the next few weeks to show some more of the structure in its early stages.
Macca