Australian Tornado 26th January 2007

[Michael Thompson]

Not often you see a warning from the Australian Weather Bureau like this:
-----------------------------------------
Bureau of Meteorology
Queensland Regional Office

The Standard Emergency Warning Signal should NOT be used with this message.

TOP PRIORITY FOR IMMEDIATE BROADCAST

SEVERE THUNDERSTORM WARNING - SOUTHEAST QUEENSLAND
for LARGE HAILSTONES, DESTRUCTIVE WIND and VERY HEAVY RAINFALL and a possible TORNADO
For people in parts of the
Southeast Coast,
Eastern Darling Downs & Granite Belt and
Wide Bay & Burnett Forecast Districts.



Issued at 5:25 PM Friday, 26 January 2007.


THIS INCLUDES A TORNADO WARNING.


At 5:25 PM , Bureau of Meteorology weather radar detected severe thunderstorms near the area northeast of Dalby and Bunya Mountains. These thunderstorms are moving towards the north to northeast. Severe thunderstorms are forecast to affect the area west of Kingaroy, the area southwest of Kingaroy and the area south of Kingaroy by 6:25 PM .


Very dangerous thunderstorms were located near Laidley. They are forecast to affect the area south of Esk by 5:55 PM and southern Lake Wivenhoe, Esk and northern Lake Wivenhoe by 6:25 PM .


Tornadoes, large hailstones, destructive winds and very heavy rainfall are possible.
--------------------------------------------------------------

The 'tornado' word is extremely rare here.

There is a media video ( no links sorry ) of empty coal carriages from a train that may have been blown from the rails during the storm / Tornado. It is unclear if it was just a freak coincidence that the train derailed at approximately the same time as the storm, or whether it was tornado damage.

There are pictures of other storms this day in these threads

http://www.weatherzone.com.au/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=17;t=000215;p=3

 

[MJ Poore]

Sounds exciting. We've had about 6 or 7 damaging tornadoes reported on the eastern side of this country in the past month or so. Nothing bigger than F2 though it would seem at this point, although one appears to have had a fairly long track damaging a number of remote villages in its path.

 

[Andrea Griffa]

Hi Michael, it looks like something like a low topped supercell, seeing some pics, can you confirm?

 

[Michael Thompson]

Hi Andrea,

I would not have thought low topped given that it is the height of summer and the area is 28' S latitude. The photos are of storms that formed closer to the coast where the heat was much less.

However I am still sceptical about the train being blown off the tracks.

 

[Andrew McDonald]

Hi Michael,

I just had a quick look at the radar archive at the Dalby storm and even thou its quite a distance from radar, you can make out what looks to be a fairly decent hook which passes directly over Dalby. It is quite a large place though and you would think that if there was a tornado there, at least someone would have gotten photos (same for the Laidley storm for that matter). Typically, this event occurred whilst both myself and another well respected chaser are out of the country...

Cheers,

Macca

 

[Kurt Hulst]

cool stuff The pictures of the updraft indicate to me they may have been pulse sever as the anvils did not look solid but feathery. I wasn't there so as andrew was stating i may be looking at pictures from a diffrent storm.

 

[Greg Stumpf]

I would not have thought low topped given that it is the height of summer and the area is 28' S latitude.

Low-topped supercells can occur in the summer and at lowish (subtropical) latitudes. This usually happens in low EL environments, and within tropical airmasses if the low-altitude shear can support them. The storms are dominated by warm rain processes. A prime example are those associated with tropical storms, but they can occur outside those systems.

 

[Jimmy Deguara]

I personally don't think it looks supercellular and I doubt the report at least of a mesocyclonic tornado. Storms on radar look not very well organised imo. That photograph of the whispy looking top was allegedly at the time approximately the tornado report occurred. It definitely looks multicellular:

http://downunderchase.com/friends/dave/2007/0126ds04.jpg

The news reports indicate the storm spotter was experienced so the warning was issued. How experienced can one be in a country that few tornadoes can ever be observed.

As to the Dalby storm, I think damage there was consistent with straight line winds. A whole freight train was toppled off the railway line side ways.

Regards,

Jimmy Deguara

 

[Michael Thompson]

My apologies regarding my post - I did not make it clear at all regarding where the 'alledged' Dalby train incident occurred and where the photos were taken. The photos were taken on the east side of the Great Divide where moisture is higher, and I agree the structure is messy, with no strong anvil, and more multicell looking.

In Dalby ( west of the divide ) on the day of the incident the temperatures peaked at 36C, with dewpoints hovering around 20C.

In the area that the photos were taken the temperature would have been at least 6C lower, but DP perhaps 3C higher. There was a seabreeze boundary that worked inland as the day progressed, this boundary is often favoured for action, although east of the boundary and the seabreeze is a convection killer.

My opinions about the height of the storm was based on conditions at Dalby, not from the photos.

At the end of the day we have no photos or chasers west of the divide, therefore it is academic.

The Dividing range in this area is very sharp with just a single steep range to 1000m seperarting coastal hinterland valley from inland slopes and plains, and only over a distance of <100km.

The tornado warning was based on a spotter report of a funnel cloud followed by damage to the area. Again this was east of the divide.

 

[Andrew McDonald]

I've just been shown a picture taken from about 3km (2mi) from where one of the tornadoes was supposedly reported (Laidley) and unfortunately, I think the spotter may need to attend some training. The photo shows what looks like a very outflow dominated storm with an area of lower scud. The person who was photographing is a chaser and was in a reasonable position to see a tornado IF there was one there (which it appears there was not). Perhaps the spotter saw a gustnado although the reports of a funnel cloud would suggest otherwise? Anyway - I think we can write this one off as a false report.

On another note, the damage in the area was apparently not serious (a friend of mine asked if we could add a -1 (minus 1) to the Fujita scale that the damage was so slight).

Cheers,

Macca

 

[Chris Gribben]

I concur Andrew, first time I have EVER called you that haha, the biggest give away for me was some report saying winds that gusted up to 100kmh affected the given area. Now 100kmh (63mph) would be considered a given in any decent storm or a severe warned one for that matter. However to topple a freight train given some of the ones that head into the outback is a fair effort, I concur with the straight line winds calls and given I haven't heard much more I think the BoM have done the same. The one I am more interested in is the 196kmh (122mph) gust at Double Island Pt near Rainbow Beach just north of the Sunshine Coast (about 200km N of Bris) which was a different day but there are some suspicious AWS readings.....