Storm Australian Severe Weather Forum
Severe Weather Discussion => Australian Severe Storms, Weather Events and Storm Chasing => Topic started by: zacaroo on 08 January 2007, 05:45:09 PM
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Well there has been thunderstorms forecast for tomorrow around North-Eastern New South Wales and South-East Queensland. It is about time. Hopefully it gives some good rain to the dams and the chasers get some good action :D.
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Yes I hope so too, its getting a bit too dry over here and we need the rain. I heard this storm system has good rain it. If it lasts during the night, I might go out and take a few pics :)
But nonetheless I'm crossing my fingers.
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I will be out and about to my lookouts to watch and take some photos and videos if we get storms rolling towards us. Tommorow has been forecast in the low 30's for us and that will be a real difference to what we are currently getting around 26-27 degrees.
Edit: Assuming you are talking about storms tomorrow so changed the topic to reflect 8th and 9th January 2007 to keep you on topic. Also ask about links in the General Weather (topic started) JD
Thanks,
Zac
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Things were slow to kick off Monday despite the heat (peaking about 36). Dorrigo Plateau area was first to fire as per usual. I chased south down to the Whiporie area - to about 45ks north of Grafton.
Cloud rapidly developed with a storm to my WSW by about 430pm - about the same time the BoM issued a warning for large hail and damaging winds. Some interesting base features formed and a few CGs were spotted, the closest about 10ks away. Storms were moving towards the ENE.
(http://australiasevereweather.com/temp/forum/thumbs/2007010801.jpg)
Larger view: http://australiasevereweather.com/temp/forum/photos/2007010801.jpg
(http://australiasevereweather.com/temp/forum/thumbs/2007010802.jpg)
Larger view: http://australiasevereweather.com/temp/forum/photos/2007010802.jpg
(http://australiasevereweather.com/temp/forum/thumbs/2007010803.jpg)
Larger view: http://australiasevereweather.com/temp/forum/photos/2007010803.jpg
(http://australiasevereweather.com/temp/forum/thumbs/2007010804.jpg)
Larger view: http://australiasevereweather.com/temp/forum/photos/2007010804.jpg
(http://australiasevereweather.com/temp/forum/thumbs/2007010805.jpg)
Larger view: http://australiasevereweather.com/temp/forum/photos/2007010805.jpg
The southerly change was triggering convection in many parts of the Northern Rivers now.
I had to move northwards along the Summerland Way as the precipitation approached. Very strong winds were bringing down small branches off the trees.
A large rain free base was also forming overhead. It was amazing how long this remained rain free !
I was now about 25ks south of Casino at a lookout just off the Rappville Road turn off.
(http://australiasevereweather.com/temp/forum/thumbs/2007010806.jpg)
Larger view: http://australiasevereweather.com/temp/forum/photos/2007010806.jpg
(http://australiasevereweather.com/temp/forum/thumbs/2007010807.jpg)
Larger view: http://australiasevereweather.com/temp/forum/photos/2007010807.jpg
A strong looking cell with shelf cloud structure was to the south and the rippled rain free base of the other storm overhead - this just passed over and begun to drop torrential rain to the north.
The chase continued northwards through the torrential rain and out the other side. The leading edge of a ragged gust front feature was in view. However, no lightning was observed.
(http://australiasevereweather.com/temp/forum/thumbs/2007010808.jpg)
Larger view: http://australiasevereweather.com/temp/forum/photos/2007010808.jpg
(http://australiasevereweather.com/temp/forum/thumbs/2007010809.jpg)
Larger view: http://australiasevereweather.com/temp/forum/photos/2007010809.jpg
(http://australiasevereweather.com/temp/forum/thumbs/2007010810.jpg)
Larger view: http://australiasevereweather.com/temp/forum/photos/2007010810.jpg
Intense rainfall from another cell spread through the Lismore Alstonville area. This was soon followed by hazy stratocumulus.
(http://australiasevereweather.com/temp/forum/thumbs/2007010811.jpg)
Larger view: http://australiasevereweather.com/temp/forum/photos/2007010811.jpg
(http://australiasevereweather.com/temp/forum/thumbs/2007010812.jpg)
Larger view: http://australiasevereweather.com/temp/forum/photos/2007010812.jpg
Regards, Michael
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Quite active on the Northern Tablelands and Darlings Downs at present. NSW BoM issued a STW at 4.09pm for large hail and damaged winds, mainly for Armidale and Inverell and a swathe north from there. QLD BoM issued a warning shortly before that for the western parts of the Darling Downs.
Moree sounding for 00z today is pretty good with plenty of moisture to 700, very dry above that. Some reasonable shear too.
Radar at 4.20 EDT shows a strong thunderstorm passing just to the northwest of Armidale.
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As a radar update (4:00pm Qld local time), there is a very nice looking cell west of Millmerran at the moment tracking NNE. Also a nice storm split some 50km WNW of Texas.
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Hi here are some of my pictures from yesterday in Lismore.While driving Home after seeing the RFB has collapsed with some fairly intense Rain, I found my AWS had been right under it with 255mmhr rain rates which emptied 26mm in a short period of time of approx 20mins.YTD is now 100mm quite lovely and also wishing the rest of the states that need it could have some too.
(http://www.australiasevereweather.com/rodney/20070108rjwa.jpg)
(http://www.australiasevereweather.com/rodney/20070108rjwb.jpg)
(http://www.australiasevereweather.com/rodney/20070108rjwc.jpg)
(http://www.australiasevereweather.com/rodney/20070108rjwd.jpg)
(http://www.australiasevereweather.com/rodney/20070108rjwe.jpg)
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Michael and Rodney,
I liked the colours and the fact bases were tapping the surface at the time of the chase!
Regards,
Jimmy Deguara
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Links to GFS Analysis: Monday 08/01/2007 06z
Instability: CAPE (http://australiasevereweather.com/storm_news/2007/maps/2007010806cape.png) / Liftex Index (http://australiasevereweather.com/storm_news/2007/maps/2007010806li.png)
Relative Humidity: 0300 (http://australiasevereweather.com/storm_news/2007/maps/2007010806rh0300.png) / 0500 (http://australiasevereweather.com/storm_news/2007/maps/2007010806rh0500.png) / 0600 (http://australiasevereweather.com/storm_news/2007/maps/2007010806rh0600.png) / 0700 (http://australiasevereweather.com/storm_news/2007/maps/2007010806rh0700.png) / 0850 (http://australiasevereweather.com/storm_news/2007/maps/2007010806rh0850.png) / 1000 (http://australiasevereweather.com/storm_news/2007/maps/2007010806rh1000.png)
Temperature: 0300 (http://australiasevereweather.com/storm_news/2007/maps/2007010806tmp0300.png) / 0500 (http://australiasevereweather.com/storm_news/2007/maps/2007010806tmp0500.png) / 0700 (http://australiasevereweather.com/storm_news/2007/maps/2007010806tmp0700.png) / 0850 (http://australiasevereweather.com/storm_news/2007/maps/2007010806tmp0850.png) / 1000 (http://australiasevereweather.com/storm_news/2007/maps/2007010806tmp1000.png)
Winds (knots): 0200 (http://australiasevereweather.com/storm_news/2007/maps/2007010806wind0200.png) / 0300 (http://australiasevereweather.com/storm_news/2007/maps/2007010806wind0300.png) / 0500 (http://australiasevereweather.com/storm_news/2007/maps/2007010806wind0500.png) / 0600 (http://australiasevereweather.com/storm_news/2007/maps/2007010806wind0600.png) / 0700 (http://australiasevereweather.com/storm_news/2007/maps/2007010806wind0700.png) / 0850 (http://australiasevereweather.com/storm_news/2007/maps/2007010806wind0850.png) / 0925 (http://australiasevereweather.com/storm_news/2007/maps/2007010806wind0925.png) / 1000 (http://australiasevereweather.com/storm_news/2007/maps/2007010806wind1000.png)
GFS really got the situation wrong in the forecast for the 9th. The analysis run linked below shows instability with CAPE about 1400 and a wide area of LIs -4 to -5 on the Northern Tablelands and Darling Downs. At no stage did forecast runs have those sorts of values. Shear and temperature profiles also improved between forecast and analysis time. If GFS has been a bit more accurate in its forecast then I'm sure a few chasers would have been out and about this day and observed some severe weather.
Of course you can always alter surface temperatures and try to estimate instability, but it remains an annoyance that GFS can get values so wrong so close to the actual time. Soundings can also be modified but it's usually too late to chase by the time you get to see those.
Moree sounding at 00z 9th Jan:
http://australiasevereweather.com/storm_news/2007/soundings/2007010900moree.png
Soundings available from here:
http://soundings.bsch.au.com/index.html
Links to GFS Analysis: Tuesday 09/01/2007 06z
Instability: CAPE (http://australiasevereweather.com/storm_news/2007/maps/2007010906cape.png) / Liftex Index (http://australiasevereweather.com/storm_news/2007/maps/2007010906li.png)
Relative Humidity: 0300 (http://australiasevereweather.com/storm_news/2007/maps/2007010906rh0300.png) / 0500 (http://australiasevereweather.com/storm_news/2007/maps/2007010906rh0500.png) / 0600 (http://australiasevereweather.com/storm_news/2007/maps/2007010906rh0600.png) / 0700 (http://australiasevereweather.com/storm_news/2007/maps/2007010906rh0700.png) / 0850 (http://australiasevereweather.com/storm_news/2007/maps/2007010906rh0850.png) / 1000 (http://australiasevereweather.com/storm_news/2007/maps/2007010906rh1000.png)
Temperature: 0300 (http://australiasevereweather.com/storm_news/2007/maps/2007010906tmp0300.png) / 0500 (http://australiasevereweather.com/storm_news/2007/maps/2007010906tmp0500.png) / 0700 (http://australiasevereweather.com/storm_news/2007/maps/2007010906tmp0700.png) / 0850 (http://australiasevereweather.com/storm_news/2007/maps/2007010906tmp0850.png) / 1000 (http://australiasevereweather.com/storm_news/2007/maps/2007010906tmp1000.png)
Winds (knots): 0200 (http://australiasevereweather.com/storm_news/2007/maps/2007010906wind0200.png) / 0300 (http://australiasevereweather.com/storm_news/2007/maps/2007010906wind0300.png) / 0500 (http://australiasevereweather.com/storm_news/2007/maps/2007010906wind0500.png) / 0600 (http://australiasevereweather.com/storm_news/2007/maps/2007010906wind0600.png) / 0700 (http://australiasevereweather.com/storm_news/2007/maps/2007010906wind0700.png) / 0850 (http://australiasevereweather.com/storm_news/2007/maps/2007010906wind0850.png) / 0925 (http://australiasevereweather.com/storm_news/2007/maps/2007010906wind0925.png) / 1000 (http://australiasevereweather.com/storm_news/2007/maps/2007010906wind1000.png)
Regards, Michael
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Yes, yesterday was quite different to what was initlally forecast. Nevertheless, I was planning on heading up but I had an appointment and other items I had to attend to get out of the way. I also wanted to await what happened Friday onwards. I guess there were some interesting cells on the 9th January 2007. This includes the split pair and also the cell further north.
It seems this season if you are not willing to chase and take risks, you are not going to yield the goods (or busts).
Regards,
Jimmy Deguara
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Hi Ottley,
A very impressive sequence - thanks for posting them ! I happened to be viewing the radar at the time wondering what that cell was doing. Low level shear was quite good according to 06z GFS. It's an unusual structure - how far away were you from the tornado ? It is occurring in the part of the storm you'd expect one to occur (northwest side).
Bet you wish you had a video camera now ! :)
Regards, Michael
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Otley,
How huch time elapsed during the sequence of images?
I have to say that it is a very unusual cloud formation which is very unllike a typical tornado in structure allthough it does resemble a landspout to a degree. I don't agree that I can see striations in it, it looks too weak to me as there is no tight vortex that you would get even with a weak tornado.
I would be very interested to know what it was.
I also noticed the sign in one of the pics with the town of Elsmore on it! The location of an historic powerfull tornadic event.
Jeff.
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What a really cool sequence of photos, a few of which can be animated to provide a bit more insight into what is happening.
To this end, this is a very interesting interaction, one that I personally very much doubt is a tornado. Firstly, there does appear to be a circulation but it is not rapid, (as Jeff said, timing of the sequence would be good to know). Secondly, there are thousands of photos of tornadoes around - you would never see an 'inverted' appearance with a ragged base like this in any of them (excluding dust sheaths eg Northam tornado, but dust is heavy). The cloud base shows no evidence of a circulation which you would expect -- a tornado of this size is rather large. Photos do also that the 'vortex' is getting sheared off to the left with time, while the cloud motions above seems to be to the right. Such an interaction (outlfow) has likely produced this transient vortex (seems to be transient based on the location/movement with respect to the hills in the foreground. Rain-cooled air would have helped with condensation. Also, given the hills, there is every chance the vortex did not reach the ground either.
All that said, this is really interesting nonetheless. Time-lapse of this would have been awesome since it would reveal what's going on quite clearly.
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Hi,
Firtly, very nice structures in your pictures and certainly would have been exciting to be there.
I am not convinced it is a tornado. Perhaps there is a condensing vortex. In fact, from my observations, it seems it is reacting to outflow from the microburst observed in picture 3. The storm was reasonably high based and seemed to have been reacting with moisture and/or outflow. If you have a horizontal vortex and updraft air is tilted towards it, then the cooler air may condense creating various types of structures. Take for instance a similar scenario although not the same looking structure taken 28th December 2005 on the mid north coast:
(http://www.australiasevereweather.com/photography/photos/2005/1228jd06.jpg)
The ends of the roll clouds are tilted downwards slightly. Look at the left hand side of my image here and you will see even lower scud. I know not the best analogy but I do believe these are the sort of dynamics in place. Very chaotic environment.
One other aspect I find interesting is that you suggest little or no wind. Tornadoes tend to thrive in situations with strong inflow - usually powerful inflow ir at least great shear between inflow and outflow interactions.
Regards,
Jimmy Deguara
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Hello
When watching a southerly buster move along the coast east of Braidwood NSW, I saw similar roll clouds, scud clouds and overall a chaotic environment, especially on the frontal boundary itself where the cold air is thrust into the warm air. Given the proximity of the coastal mountains there, you can get interesting low cloud formations and quite violent and chaotic formations at times sometimes similar to what has been observed.
Harley
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Hi John,
I have had so many debates on other forums in regards to tornado density in Australia. This will always come up in any argument. But given what I have observed overseas and the storms that produce them, there are usually some characteristics that somehow show up with various tornadic events or let's say tornado warned events. One that I mention above wind inflow - localised observations were near calm in the area. Such conditions alone make me suspect. Any tornadoes and even aggressive wall clouds I have seen here and in the U.S. usually co-exist and are often formed by strong low level wind shear. Of course if the atmosphere locally was extremely unstable CAPEs of perhaps 6000 or more, then I would be looking fairly carefully.
To me taking one backward step away from all excitement (that finally we have seen a tornado and they are not so rare after all), the whole structure of the storm and developing low level clouds is consistent with outflow as David suggests in his post.
When you even see one tornado no matter what the dynamics, the rotation is unmistakable - so rapid you often know that something is going to happen. Forget about fast forwarding video for timelapse. This is real time. And I mean rotation in the cloud base not only the vortex! The ckloud base is circular and not linear (of course in the case of landspouts, you have misacyclones as compared to mesocyclones) but you still observe localised rotation.
Ok, so we await damage survey. We then have to distinguish between tornadic damage as compared to straight line winds. Let me know if you see adjacent telegraph poles leaning in opposite directions and I am all ears. Or perhaps trees doing something similar.
Certainly take photographs of whatever you observe and post it on here.
Regards,
Jimmy Deguara
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And i think its fair to say that we really cant make an assessment on the limited dataset we have: I notice you talk of unlike any tornado ive seen or seen pictures of: But really is this representative? There is still many things we dont know about tornadoes: and our knowledge is limited to the last 70 years really(photographic evidence) We are still discovering that more and more tornadoes(or subvariants) occur every year without our noticing. So whats to say this isnt some sort of fell agree that scud cloud can form the appearance of various shapes, but there are (for those who look) striations
While I think that this cloud structure looks cool and it is definately an interesting structure at that, I think that throwing away all conformity to what we know about the structure of tornadoes and their parent storms whenever we see a strange cloud structure that looks like a possible tornado is illogical. There are certain dynamics that are always involved in the production of all the various types of tornadoes.
Definitely striations within the vortex are visible in images 5,7,8,9 and within the disapation stages there is a horizontal clear column of rotating air. Roping out characteristics are also evident, as shown in the later images
John, I don't understand how can you say for sure that there is a rotating column of air? That disapating structure is no different to the disapating structure of regular scud, and we are viewing still images not video. And I think that to say that it's roping out suggests that there is in fact a rope funnel, which I don't think there clearly is in any of the pictures.
This is a rope funnel.
rope funnel/tornado (http://www.australiasevereweather.com/photography/tornadoes/funnel_tornado_waterspout0009.html)
Jeff.
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John,
Let's get back to the feature we were discussing than move off tangent to artistic thoughts or alternative science. Strangely you sometimes turn to literature for definitions but now we have to look for alternatives to explain this unusual feature. I am pretty sure the Chuck Doswell's of this world have both practical and theoretical experience in tornadogenesis far beyond what I can even comprehend although that is not stating much. They have never claimed to know enough or know everything - I know because I deal with these top scientists regularly.
The feature posted in several pictures on the first page is the main focus here as you would note in the subject. Statements were made that this was a tornado - not even the word 'possible' thrown in. Somebody supply conclusive evidence with existing literature to support their claims rather than congratulations all around for the incorrect reasons.
I think that in itself is scientifically dangerous. I put in my reasons as to why I don't think it was a tornado. Let's await:
- a damage survey
- perhaps documented examples that are similar in nature to this structure - this is not conclusive but at least it may help with further investigation on what and why the feature tends to appear like a vortex.
- photographs of similar features that provide evidence that this may indeed have led to a tornado.
Now if it is not a tornado, then let's look at what it may be because it is quite an awesome structure in itself. It doesn't have to be a tornado to be interesting!
Regards,
Jimmy Deguara
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The topic is "Thunderstorms SE Qld/NE NSW January 8th - 9th 2007" - Can we continue the discussion about the conditions in this event. Technical discussion belongs in the appropriate thread. Otherwise the thread will be locked. Discussions on tornadoes and associated definitions have been moved to the technical discussion thread. http://www.australiasevereweather.com/forum/index.php?topic=323.msg2133#msg2133
Has a damage survey been conducted or any pieces of evidence collated Ottley Irwin? I suspect not unless you lived nearby.
Regards,
Jimmy Deguara