Author Topic: Thunderstorms SE Qld/NE NSW January 8th - 9th 2007  (Read 20408 times)

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Offline Jimmy Deguara

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Re: Thunderstorms SE Qld/NE NSW January 8th - 9th 2007
« Reply #15 on: 18 January 2007, 03:02:24 PM »
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
« Last Edit: 21 January 2007, 07:07:47 AM by Jimmy Deguara »
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Jeff Brislane

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Re: Thunderstorms SE Qld/NE NSW January 8th - 9th 2007
« Reply #16 on: 20 January 2007, 10:41:33 AM »

Quote
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.

Quote
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

Jeff.
« Last Edit: 20 January 2007, 11:12:16 AM by Jeff Brislane »

Offline Jimmy Deguara

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Re: Thunderstorms SE Qld/NE NSW January 8th - 9th 2007
« Reply #17 on: 21 January 2007, 04:11:28 AM »
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
« Last Edit: 21 January 2007, 04:17:08 AM by Jimmy Deguara »
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Offline Jimmy Deguara

  • Australian and Tornado Alley storm chaser
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Re: Thunderstorms SE Qld/NE NSW January 8th - 9th 2007
« Reply #18 on: 26 January 2007, 03:15:48 AM »
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
« Last Edit: 26 January 2007, 05:47:57 AM by Jimmy Deguara »
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