Author Topic: SE Aust Severe Storms (incl possible VIC tornadoes) 19 - 22 December 2007  (Read 43538 times)

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Offline Brad Hannon

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Re: SE Aust Severe Storms (incl possible VIC tornadoes) 19 - 22 December 2007
« Reply #45 on: 25 December 2007, 06:26:55 PM »
2nd wall cloud, looking West, Princes Hwy south of Werribee, Brisbane Ranges in background.
hmmm June 2nd......

Offline Brad Hannon

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Re: SE Aust Severe Storms (incl possible VIC tornadoes) 19 - 22 December 2007
« Reply #46 on: 25 December 2007, 06:35:35 PM »
These final four pics are of the suspected funnel with a photoshop high contrast version for comparison.
hmmm June 2nd......

Offline Jimmy Deguara

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Re: SE Aust Severe Storms (incl possible VIC tornadoes) 19 - 22 December 2007
« Reply #47 on: 25 December 2007, 11:56:16 PM »
Brad,

The first set of photographs looks like a wall cloud and a nice one but obviously not clear and seems to break down perhaps due to competition or something like that.

The second one looks like a shelf cloud to me but then again video would confirm better.

The 'funnel' in the third set of images are hard to build a proper picture but on the picture seems to me to be fragmented scud but again video on a tripod would show more.

You obviously had a great day and lots of storms to choose from - no chance of sunburn or busts here.

Regards,

Jimmy Deguara
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Offline Jimmy Deguara

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Re: SE Aust Severe Storms (incl possible VIC tornadoes) 19 - 22 December 2007
« Reply #48 on: 26 December 2007, 12:15:45 AM »
Hi,

In fairness of a scientific debate and analysis, it is a good idea to post some other pieces of information that come to light.

Clyve sent these images via email in order to back up his claims of a 'large tornado'. I have included his times and statements with respect to the images portrayed.

------------------------------------------
Hi Jimmy as mentioned on our phone discussion I will send you stuff re the Ballarat/Skipton storms over the next few days, I don't know how to set up a video for the net but if not I will send you a DVD of the main sequence....
 
In this image taken around 1541hrsz it shows the 'tail end Charlie ( I say tail end Matilda)...This is the main inflow area and part of the left mover split. The rain behind is actually part of another storm..right moving and the northwest end can be seen. I positioned north of the storm and looking south/southwest.



In this image the very end of the line (northwest end) that extended well to the east with a large RFB, again in the distance the rain is from the right splitter in a video sequence the rear lowering is rotating cyclonically and it was here I thought some action may have started however the updraft pulses were moving east along the RFB then maturing down wind of the steering mid level flow.



In this image taken at 1546hrs the first funnel appeared but was short lived, I did not take still image of the rope that appeared further along the line to the east but did a video sequence of it...this funnel lasted about 2 minutes before rapid dissipation...C



This is one of the still images taken at 1550 hrs and shows the Tornado in full swing the tornado was rotating cyclonically and the wrap around banding can be seen on both sides of the tornado, I would estimate the motion towards the east/northeast around 40 or 50 kilometres per hour...



This a closer look at the tornado with associated accessary cloud elements, at this point about 1552 a skirt appeared  lower down and the central rather broad funnel it was between 8 and 10 kilometres distant...



In this image the tornado is just about to dissipate there is still a connection to the ground but the overall size of the rotating area is large, note the collar along the top under the main RFB, the remains after this image became rain affected very quickly as the cell collapsed..



After the collapse of the tornadic storm a strong outflow followed and came around the rear of the main precip area to produce this veil that moved first north then northeast and finally headed east and later kicked off a strong storm east of Ballarat, I followed the outflow band from the Ballarat storm complex...



After following the Ballarat outflow this storm developed time 1846hrs (Among others) but by far was the strongest however I regard this storm as outflow dominated with a constant rear downburst pulse as each updraft matured then kicked back along the flanking line....best regards Clyve Herbert



You have my permission to put these images on your site if you want and use my comments if you wish...Images taken with a Canon 400D 18 to 55 lens set to auto....I will also retrieve captures from my Panasonic GS 300 with a capacity of 3.2 mg stills of the entire event...Clyve  H

--------------------------------------

I will allow others to comment.

What I would like to know is how long was this 'large tornado' on the ground? When diid this 'large tornado' become 'bell shaped' and almost a wedge status? These were claims made on the phone conversation. What comments did the Bureau have of this 

Feel free to send the video and place online all unedited 11 minutes of it - we can certainly spare the bandwidth.

My point of view still stands that this feature occurs along as a result of what appears to be developing outflow. This is shelf cloud central and a nice shelf cloud in that.

I would still like to see the video before developing a proper picture.

Regards,

Jimmy Deguara
« Last Edit: 26 December 2007, 12:30:46 AM by Jimmy Deguara »
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Offline nmoir

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Re: SE Aust Severe Storms (incl possible VIC tornadoes) 19 - 22 December 2007
« Reply #49 on: 27 December 2007, 03:29:34 AM »
I would like to see a damage survey on the area , surely a large or even small tornado would leave some significant signs even in a wheat field , any questions on the existance of the tornado would be answered by this easy task. To me , having never seen a decent tornado , the feature appears messy and the lack of any raised dust swirl at the base of the feature makes me suspicious , also i want to see video and rotation!

Nick
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Offline Brad Hannon

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Re: SE Aust Severe Storms (incl possible VIC tornadoes) 19 - 22 December 2007
« Reply #50 on: 27 December 2007, 02:30:24 PM »
Hi Nick, I agree re a damage survey for this tornado event.  Seems a lot of talk on WZ about a tornado and no-one talking about any damage path or evidence of rotating wind damage.  Hopefully some emerges, along with some video :)

By the way, that's a strapping young lad in the bottom left of your avatar!

Brad.
hmmm June 2nd......

Offline Brad Hannon

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Re: SE Aust Severe Storms (incl possible VIC tornadoes) 19 - 22 December 2007
« Reply #51 on: 27 December 2007, 03:23:22 PM »
Melbourne storms - Wed 19 December

A local chase (5mins!) took me to the highest point in metro Melbourne where I caught these images at dusk.  I returned to this spot after 9pm to watch a short lightning display over the city.
Brad.

hmmm June 2nd......

Offline Richary

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Re: SE Aust Severe Storms (incl possible VIC tornadoes) 19 - 22 December 2007
« Reply #52 on: 29 December 2007, 01:11:36 PM »
Hello, now it appears that NSW got a tornado out of that as well...

"A mini-tornado that last week damaged Lake Cargelligo's main water pump is being blamed for the deaths of 200 tonnes of fish that washed up on its shores."

http://news.smh.com.au/riverina-tornado-caused-dead-carp/20071228-1jc7.html

Whether anybody saw it, or it was just a downpour and high wind who knows?

Offline Jimmy Deguara

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Re: SE Aust Severe Storms (incl possible VIC tornadoes) 19 - 22 December 2007
« Reply #53 on: 30 December 2007, 04:24:11 AM »
Hi,

Here are some other items from Clyve's conversation with Harald Richter (with permission from Clyve):

initial email:

hi Harald...still shaking in my sandals after bagging this tornado between Ballarat and Skipton, will send details taken at 1551Z on wide angle lens...It was a big tornado and developed very rapidly, there were two funnels at different locations prior to this setting down....The tornado became rain wrapped rapidly and dissipated after about 5 to 6 minutes, however the area of vorticity remained after dissipation with a lot of scud rotating over a wide area..very weird stuff...regards Clyve H

Harald's response:

Congratulations Clyve,

I have been training in QLD for the past 6 weeks, hence my slow response.

It seems to me that you have bagged a QLCS tornado that spun up
on the leading base of a NNE propagating line.  In the wake of
this line Ballarat cooled to a chilly 18.4 C (after 5z) with SSW winds.
Initially I thought you got onto the earlier (3:30z) supercellular activity
between Ballarat and Skipton, but eventually decided that you probably
worked the 4:50z linear segement.

The Melbourne Doppler shows that the dominating cell within the line was
located about 8 km WSW of BLT at 4:40z, the time of your observation.
I can see a number of cyclonic couplets at low levels on the 4:48z
scan, but no decent midlevel rotation.  Maybe we should sit down and
look at the data one day.

Have a stormy start to 2008,
Harald

Clyve once again to me:

Hi Jimmy...reply from Harald...Suspects a QLCS (Quasi Linear Convective system) generated Vorticity max west of Ballarat. Although will have to do a deep study on the occurrence. Strong convection may have taken advantage of the cyclonic couplets operating along the QLCS which may explain the two short lived funnels appearing before the main event...Appears tornadic developments can occur under a number of set-ups, seems if the dynamics are good a number of initiating triggers can go down the tornado generating process...regards Clyve Herbert.

-----------
Regards,

Jimmy Deguara
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Offline Jimmy Deguara

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Re: SE Aust Severe Storms (incl possible VIC tornadoes) 19 - 22 December 2007
« Reply #54 on: 30 December 2007, 04:26:27 AM »
Further conversation regarding another cell:
------------

Hi Harald..Later in the evening followed this big storm from Creswick to Castlemaine (formed on outflow of Ballarat complex)...Note the rear outflow along the ground and under the flanking line....I suspect this storm may have achieved supercell status...regards Clyve H


Harald's response:

Hi Clyve,

I agree with your supercell suspicions - the storm had
a deep and persistent mesocyclone on radar, moved left of
steering and showed a persistent TBSS (hail spike).
Nice catch, and this one has some impressive radar data
to go with the impressive visual you took.

Harald

Hi Jimmy also appears that the storm south of Castlemaine later that day may have been significant although I did not see any rotation of significance near the inflow outflow interacting interface..regards Clyve H....PS If you want you can put Haralds comments up on the images applicable...

-----------
Regards,

Jimmy Deguara
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Offline Jimmy Deguara

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Re: SE Aust Severe Storms (incl possible VIC tornadoes) 19 - 22 December 2007
« Reply #55 on: 30 December 2007, 04:59:31 AM »
In relation to the comparisons of TVS strength signaures relating to tornadoes generated by supercells and those occurring along Quasi-Linear Convective Systems (QLCS)



Taken from an extract of the article:

http://www.cimms.ou.edu/~kmanross/QLCS/QLCS_-_TWG_Comparison.html

In my opinion, if this was indeed a tornado Clyve has captured, there is a high likelihood it was not a large tornado based on this data set and also visually. I fail to see a significant and consistent debri cloud associated typically with large tornadoes. I do see outflow in one of the earlier shots.

We still would like to see the 11 minutes of video associated with this ' large tornado'. This would clarify so much in the behaviour of the storm as a whole. I will post it immediately once supplied as well as results from a damage survey.

We can conclusively suggest that this is a 'possible' tornado.

Regards,

Jimmy Deguara
« Last Edit: 30 December 2007, 06:58:39 AM by Jimmy Deguara »
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Re: SE Aust Severe Storms (incl possible VIC tornadoes) 19 - 22 December 2007
« Reply #56 on: 30 December 2007, 05:03:50 PM »
Clyve has put up a load of new photos here: http://www.stormchasers.au.com/20_12_07.htm

However, I'm still not sure why it is so difficult to put the video online instead of just captures!

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Re: SE Aust Severe Storms (incl possible VIC tornadoes) 19 - 22 December 2007
« Reply #57 on: 30 December 2007, 05:19:18 PM »
I am certainly no guru on this but while there was a funnel shaped thing coming down from the cloud base, I see no evidence of a tornadio. Given my very limited experience in this I would just say it was cloud. Having seen those photos unless there was a damage trail on the ground I just don't think it happened. The funnel as such was not well defined, no debris and no clear evidence of rotation.

Offline Mike

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Re: SE Aust Severe Storms (incl possible VIC tornadoes) 19 - 22 December 2007
« Reply #58 on: 30 December 2007, 07:17:46 PM »
Mmm yes I'd have to take an educated stab and also say it's a tornado.  It's attached to the cloud base, there was visible rotation mentioned and there is a condensation skirt around it - like Jimmy eluded to, without the video it's really hard to pinpoint every detail, the video would definitely confirm it.  Perhaps some more pursuation may get it on the forum?

With my limited knowledge of such things also but I'm confident of it being just what most have said - a visible grounded funnel.

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Offline Jimmy Deguara

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Re: SE Aust Severe Storms (incl possible VIC tornadoes) 19 - 22 December 2007
« Reply #59 on: 31 December 2007, 04:07:46 AM »
Hi Mike,

I am just curious as I may have misinterpretted it - do you think it is a tornado or not a tornado? Yes said it is a ground funnel? Just a little confusing to clarify. Perhaps get Reed Timmer into this discussion during their quiet time Mike.

My point again - rotation is difficult to assess and the claims for the whole time of conversation is that this was a 'large tornado' to 'wedge tornado' - that it is not. Rotation is difficult to determine from the quality and brief duration of video provided on media.

Video stills without sufficient information is pointless. You take it - Clyve suggests the tornado was on the ground for 5 to 6 minutes. Even taking 5 minutes into consideration - at 25 frames per second even, you have

5 x 25 x 60 = 7500 possible frames

Unless we know the times of these specific stills, it is a useless exercise in verifying ground contact for the full duration of 5 to 6 minutes. This is why he raw video is important.

Regards,

Jimmy Deguara
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