Topic: NSW / QLD / VIC Storms (incl Nimmitabel tornado and other supercells): 22-26 Dec 2008

[nzstorm]

Great hail footage there Ben.  The funnel cloud is possibly a little landspout funnel independent of the mesocyclone.

[Dave Nelson]

Hi,

"A particularly severe thunderstorm cell has been detected to the south of Grafton, with data from weather indicating it could produce very large hailstones. This cell is likely to pass very close to Grafton city around or shortly after 3pm."


Regards,

Jimmy Deguara

Hi Gang,
              Back home after 3 days in the NE NSW got home at 11pm and have to work today 
   Cindy and I watched and photo'ed that storm as we travelled up the Hwy between Armidale and Glen Innes
It was a pretty mean storm.   Oher storm cells around the area as well tho weren't as wild looking till the one that came
through Glen Innes  and on to Tenterfield later that evening  and as Jimmy also found out it dropped some pretty good
hail

cheers
Dave N

[Jimmy Deguara]

Hi David,

On what date was the storm you mention occurring? The warning I mention was for the storm south of Grafton heading to Wooli on the 24th December?

The Tenterfield - Stanthorpe storm occurred on the 25th December 2008.

Regards,

Jimmy Deguara

[Michael Bath]

Weather data for Wednesday 24th December which shows the supercells near Grafton, Kyogle and west of Brisbane.


---> 1km VIS satpic loop


---> Grafton 128km scale radar loop

---> Grafton 256km scale radar loop


---> Brisbane 128km scale radar loop

---> Brisbane Doppler radar loop

---> Brisbane 256km scale radar loop


Brisbane 00z

Moree 00z


Also, further discussion about the tornado between Nimmitabel and Cooma on the 23rd December is here


MB

[Mike]

Winds are just amazing through the levels.  I just can't grasp how you can have a strong cap and cin with little or no CAPE & LI but get supercells. It's something that I need to get my head around when removing our indices from southern counterpart storms that this proves that you don't necessarily need big numbers to get such severe storms.  I'll have to look through the storm chase reports on the forum and study them!

[James]

Winds are just amazing through the levels.  I just can't grasp how you can have a strong cap and cin with little or no CAPE & LI but get supercells. It's something that I need to get my head around when removing our indices from southern counterpart storms that this proves that you don't necessarily need big numbers to get such severe storms.  I'll have to look through the storm chase reports on the forum and study them!

Hey Mike,

Those soundings are morning soundings and don't show the true temp/dp. I imagine the temps would have hit the low thirties which when re-plotting on the sounding would give a true indication of the set-up in terms of cap, instability, energy etc.

James

[Dave Nelson]

Hi David,
On what date was the storm you mention occurring? The warning I mention was for the storm south of Grafton heading to Wooli on the 24th December?
The Tenterfield - Stanthorpe storm occurred on the 25th December 2008.
Regards,
Jimmy Deguara

Ohhh dear,
                       Sorry Jimmy,   after 2200km in 3 days of  NE NSW driving I am just a little frazzled and not thinking clearly
  I was referring to the 26th Dec,  there was quite a good storm moving nthwards from Dorrigo reg. and on to Grafton
area before it died out.   We watched and photo'ed it as we travelled nthwards between Armidale and Glenn Innes

ciao
Dave N

[AaronS]

Hi all

New to the forum. Got some photos of damage from the Nimmitabel tornado. Was in the area and forgot the camera but tracked it down and used my mobile. Damage path was over 200 m wide and it was obvious that it was on the ground for more than a km. Either side of that we ran out of trees for it to destroy. Very humbling to be standing among the wreckage of a tornado. Let me know if anyone wants more info.

This tree was nearly two arm span circumference at shoulder height

[Jimmy Deguara]

Aaron,

Just briefly, I don't think I can make any realistic judgements on the evidence provided from what I have seen. I need to know the soil type and if it was dry or moist at the time? Do we have a before or after shot - comparison of similar vegetation nearby? Any buildings? Any embedded objects? Nice tornado and from the structure of the tornado it was certainly looking like a drier tornado and therefore in some form of steady state? Are there other pictures of the tornado? I would think that F2 could have been reached in this tornado. F3??? Unsure - if we are talking violent tornado - brick walls caved in cars and tractors tossed around - not thrown of course, is there any evidence that would lead us to such a conclusion. Remember, the F-scale is a damage scale related to ranges of wind strengths - it's not a tornado intensity scale.

[AaronS]

A little bit more info. No photos of specifically of neighbouring trees but you can see some in the background of the photos. A definite distinction between damaged an undamaged trees. This is in basalt soils, rocky but deep. It would have been dry for a while so trees could have been weakened. There were very few uprooted trees, most had been snapped. No damage to buildings thankfully though it was only several hundred metres from the Myalla homestead! A telegraph pole has been replaced. Did not notice any embedded objects but then again there was probably nothing to embed in the trees.

Can we compare damage from a tornado to straight line wind damage or does the fact that some of the damage is created by winds coming from the opposite direction confuse things? I have seen plenty of storm damage growing up with trees cracked etc. but what I saw here differed in two ways. 1) I have never seen them snap so far down the trunk and 2) the trees that I have seen break in the past have had a much larger crown so more surface area for wind to catch and cause a fracture. In general neighbouring trees are not particularly tall and have quite a sparse leaf cover. The type of tree you expect to see in a wind blown, dry and cold area.

There may never be an accurate estimate of the power of this thing, but for me personally it was still worthwhile spending an extra hour while I was down that way to track down the damage.

[Michael Bath]

Thanks for posting the images Aaron. It's been great to see some follow up to this event. Pity only the one photo of the tornado has surfaced.

Are you able to post the location map please ?

regards, Michael

[dazz10]

Hi I am Darren,
I live in Cooma and I seen that cell it just went by Cooma by about 25 km I have video of that storm on my website: http://dazz10.webs.com/

It is only short but you can see the structure of the storm and the cloud dropping down and you can see a bit of a wall cloud right at the start of the video.

I went out to where the photo was taken the next day and you could see where the tornado went through there were a few trees in the fields where there is know trees and fences down but lucky know houses were destroyed but it was so cool anyway thanks all.

[Michael Bath]

Hi Darren,
Do you know the times your video was taken ?

http://dazz10.webs.com/apps/videos/videos/view/4526640-start-of-the-tornado-near-cooma

MB

[Jimmy Deguara]

Thanks for posting.

And exact location please (edit JD)? This storm in your video shows a much wetter portion of the storm.

Regards,

Jimmy Deguara

[dazz10]

Hi yes the video was taken at about 1:30-2:00 pm and it was next to monbeaf looking towards nimmitabel. and the first bit of the video was out our front door .there was hail about the size of golf balls. and i had a report of hail filling a dam full of hail .and they said they could just about walk accross the dam and the tornado striped all the leaves off the trees and riped some of them out of the ground. this person does not want to be named but his land is about 15km from cooma on calaminda road near the motor bike track.it would be about 3 to 4km from where the pic was taken on the highway to the north and the video was to the east of cooma ithink from memory the storm started near delgety and headed north towards michalago and the area there are no trees much just grass plains but if i can think of anything else i will let you know.if you stop the video at 39 seconds you can see some thing on the ground.it took me a long time to get the video off the camera i had to use a firewire http://australiasevereweather.com/storm_news/2008/radar/20081222/canberra128.htm here is a link to that storm that day thanks guys.