Topic: Tornado Warning for Queensland - your thoughts?

[Jimmy Deguara]

Hi,

A Tornado Warning was issued in SE Qld 26th January 2007. Here is the detailed warning as it stood on this day:
-------------------
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.


A more general severe thunderstorm warning is also current for the Central Highlands & Coalfields and parts of the Central West, Wide Bay & Burnett, Darling Downs & Granite Belt and Southeast Coast Forecast Districts.



NOTE A TORNADO HAS BEEN SIGHTED IN THE LAIDLEY AREA. PEOPLE IN THE PATH OF THIS STORM BETWEEN LAIDLEY AND ESK INCLUDING THE COMINYA AND LOWOOD AREAS SHOULD SEEK SHELTER INDOORS.
The Emergency Management Queensland advises that people should:
* Move your car under cover or away from trees.
* Secure loose outdoor items.
* Avoid driving, walking or riding through flood waters.
* Seek shelter, preferably indoors and never under trees.
* Avoid using the telephone during a thunderstorm.
* Beware of fallen trees and powerlines.
* For emergency assistance contact the SES in your local government area, listed in the White Pages under either State Emergency Service or your local council.



The next warning is due to be issued by 6:20 PM.


This warning is also available through TV and Radio broadcasts, the Bureau's website at www.bom.gov.au or call 1300 659 219. The Bureau and Emergency Management Queensland would appreciate this warning being broadcast regularly.
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What are your thoughts about the validity of this warning given that very little evidence has been supplied to support it? Or have you found evidence - pictures, reliable reports, etc? Obviously the Bureau did feel compelled to issue the warnign based on an experienced observers' report.

Regards,

Jimmy Deguara

[Jimmy Deguara]

Here is what WZ forecast climate summary had to say:

The warnings covered much of southeast QLD and shortly after 5pm EST tornadoes were being mentioned in these warnings based on observer accounts. Soon afterwards the towns of Dalby and Laidley were hit by tornadic winds, causing serious damage to property.

Were Laidely hit by the same storm? The description and behaviour of the weather at Dalby was one of very low rainfall and powerful winds unroofing homes and other buildings.

Regards,

Jimmy Deguara

[Michael Bath]

I agree that the BoM should add it to the warning if they feel they have a report from a reliable spotter. Though I would hope they follow it up requesting photos or do a damage assessment.

The Brisbane radar for this Laidley event, and also the Dalby storm can be seen in these loops.

http://australiasevereweather.com/storm_news/2007/radar/20070126/brisbane128.htm

http://australiasevereweather.com/storm_news/2007/radar/20070126/brisbane256.htm

You didn't have to wait long for these, John
MB

[David C]

Hi Jimmy,

As I mentioned in a post many months ago, I suspected we would see a 'special' type of warning come out of Brisbane this season - only to learn that the Doppler was down due to a lightning strike. Anyway,,,,,let's just say, and I have not been following severe weather all that closely this year, that yesterday was NOT what I envisaged as the inaugural tornado warning day. Overall, I have mixed feelings regarding this warning.

It is a difficult situation over here for the BoM. Firstly, tornadoes are rare (and by extension, strong/violent tornadoes are even rarer)'. Second, the (Doppler) radar network is insufficient for the most part. Third, 'ground truth' observations are unreliable since the vast majority of people are not adequately experienced or trained to know what they are looking at (including 'chasers' as evidenced on TWZ). This all works against the BoM they are hard pressed to provide 'systematic' tornado warnings as opposed to the ad hoc one we saw yesterday. To illustrate this, myself and Paul Graham saw rapid cloud base rotation and a debris over North Ryde a few years back. Paul called in the warning but it was not noted at all in the warning, despite the storm being a very intense supercell (and luckily a weak tornado).  So the whole process is very subjective and destined to fail eg is a warning based purely on the spotters description (consider the 'tornado' that Otley photographed a few weeks back -  a description of that would indicate a large tornado with boiling clouds to the ground. Yet it most probably was not a tornado).

Going back to the first point. Tornadoes are rare in Australia - are they(BoM)/ we prepared? If they did issue a warning how effective would it be? Would people take it seriously?  How would the media react to a tornado warning? Getting a tornado warning service to 'work', in the absence of a tornado disaster in the meantime, is like bringing about a cultural change. There would clearly be a requirement for the BoM to educate people on tornadoes in Australia, the new technology (radars) and the new warning service that will be used if required......and, of course, what to do. Not just throw them on the web and hope for the best.

Regarding two, we might have a decent Doppler Radar Network over the next 5-10 years and this will pave the way for serious progress (not to mention by that time every man and his dog will have a high quality videocam in their mobile phone and the capability to upload in real-time for instant verification which will take care of three!). In all seriousness though, the BoM spotter network is in need of an overhaul....things have moved on since the introduction of the spotter card in 1989/1990.


So, summarising my view, I can understand why a warning was issued and I'd say whoever issued it is a visionary, and this is progress!!!!! (you can bet this 'willy willy' will be logged as a tornado to help with the accuracy ratio). In truth though I think such a warning serves to illustrate how far things are to go before such a 'warning' is truly a useful warning (well, far more often than not!).

[Jimmy Deguara]

I too think it is fair to say the warning yesterday was validated from the BoM's perspective given it was issued based on an 'experienced spotter's' observation. But what is an experienced spotter in this country particularly in regards to tornado verification. How many tornadoes could this person have observed in real life? I would require to know more about the basis underlying the warning being issued before I can comment further on this issue.

The handling of its (the warning) release to the public and media require constant review. Tornado warnings although rare have been issued on more than a few occasions - two from my immediate memory in Victoria and two in Queensland. Why one was not issued with Paul Graham's and David Croan's observation with a clear and dangerous supercell in early 2006 defies belief.

Suffice to say, there was some confusion in the warning itself. First, the length of the warning and the combinations within the warning left so much room for misinterpretation - and that we found amongst the various media reporting on the event - 'mini-tornado' as compared to 'tornado'. Second, were there one or more tornadoes? And one or more thunderstorms striking a township in question? I don't think the Bureau seemed prepared really to issue such a warning to the public given various scenarios deserve different levels of warnings. I guess in the heat of the moment, the decision was to just issue the warning and hope for the best. Even though one township was mentioned  in the warning Laidley, the tornadoes or tornadic style winds were associated with Dalby which being a larger township sustained more media reportable damage and became the highlight of the media - well at least here in Sydney (train derailment, houses destroyed). And you cannot blame the media here given the length and combination of the warning. I think a separate warning should have been issued for the tornado warning to ease any confusion.

I take on board David's discussion of how the public will perceive this warning and so to the media. I was contacted by channel 10 news desk and asked about any information or contacts of anyone who may have observed the tornado. So the media were odds on to the fact that this warning was not the so called mini-tornado - well definitely in terms of this news person anyway. So surprisingly, the issue of this warning seemed to bring out more tornado terms within the media. So it seems the media were trying to relate to what they report in the United States news coverage for a change. let's at least give them credit for that rather than bicker the use of the word - mini-tornado as it seems to be happening once again on WZ.

From a media, public education and the Bureau's perspective, this would have been far more positive if the confirmation was validated. This is where I draw the line. Was it really confirmed? Where is the traditional damage survey by the BoM or are they relying on SES photographs? Will this be put down as a 'tornado' within the severe weather database or will the word 'possible' be more appropriate? I wish someone can verify this point rather than having to wait 2 months.

Nevertheless, the outcome of this is now clear from a TWZ perspective - there seems to be no doubt amongst individuals that this is an exciting tornadic event coming from a 'definite supercell'. We have a new breed of chasers with the incorrect perspective of what supercell verification requires let alone tornado verification. Further, it seems that the so called rare unexplained events are tending to become tornadoes including twisting of trees and obliteration of homes. Well it is more exciting than microbursts I guess and it feeds the most damaging statement ever - "Australia's lack of population and tornado density argument".

Deviating slightly from this topic relating to the post analysis of this event and how it is received and reported, it is extremely important that organisations and senior chasers educate and lead the way in accurate reporting of this event and others for that matter. As mentioned above, the use of the words 'possible' and perhaps 'probable' and to promote discussions/questions are far more effective scientifically to uncover the clues as to what really occurred. I believe much of this has come about based on several years of exaggeration and misconceptions arising from some chasers. But we won't go there.

I do believe that improvements in technologies as suggested by David cameras on mobile phones, digital cameras, video cameras, webcams, satellite remote sensing imagery and an expansive network of doppler radars will help draw us closer to the truth. Until then, one cannot look in despair at the ever increasing contaminated records particularly in regards to supercells and tornadoes. Time will tell.

Regards,

Jimmy Deguara

[Michael Thomas]

I was quite suprised to see the mention of a tornado in BoM warning. The conditions on the day were far from what I'd expect from a typical tornadic setup (ie. relatively high LCL, weak low level shear, CAPE < 2000 j/kg). That is not to say a tornado wasn't possible as I have read of many examples of tornadoes forming in seemingly benign conditions. I agree that the storm was probably a supercell based on radar and photos I have seen though this doesn't mean that the storm was therefore capable of producing a tornado. Personally, I would have to have a lot of trust in the spotter to issue a tornado warning.

I actually would like to see a more detailed severe storm warning system in place in Australia. Also, I think convective outlooks would be nice as well similar to what are released by the SPC in the US. I say this because just saying 'thunderstorms likely' or even 'severe thunderstorms' really doesn't really give an indication on severe storm potential. The truth is some days tennis ball size hail is a real possiblity and others it simply isn't even though storms may be classed as severe.

Michael

[Jimmy Deguara]

Consider this photograph which was the alleged 'tornadic supercell'
photo courtesy Dave Sercombe

I am not totally convinced it as a supercell. The storm was low topped from a distance and has multiple towers when it was alleged to have a tornado so I am not sure how anyone can suggest supercell structure. Multiple towers to me are indicative of multicellular behaviour. From a radar perspective with no other storms shadowing it from radar, the storm was only in brief periods intense - once again more of a sign of multicellular behaviour. The latter 'enhanced' photographs show outflow and not much in the way of inflow characteristics. Although the storm deviated it was merely because of it developing along a boundary and the deviation was not very pronounced. The radar shows disorganised cell reproduction particularly as it headed further north. Strange how the chaser only chased the cell when hearing of it producing a tornado? All of a sudden it became the storm of the day and an 'obvious supercell'. I would have liked to have observed even a minute's timelapse and you would see outflow pushing out. A supercell in this situation would have controlled its own inflow. No reports of inflow from the chaser.

Take for instance this cell that was intercepted in 2000





and compare the alleged funnels of this cell

photo courtesy Dave Sercombe

That is a mighty base too - but not a mesocyclone base - but developing cloud under new multicell towers.

This is a high based mesocyclone on a similar sized storm and observed by several chasers to have visible rotation on a day with more favourable shear, lapse rates and CIN.




Moving onto the storm that occurred near Dalby seemed to have interacted with the other line of cells and perhaps briefly intensified and then collapsed. It also produced powerful straight line winds to remove the freight train from the railway tracks rather than scatter one or two carriages in the field.

Regards,

Jimmy Deguara

[Michael Thomas]

Good points above, maybe I was jumping the gun in saying it was probably a supercell. I was basing what said on how the storm moved left of the steering winds and the close up photo of the storm's base, not so much the photo of the storm from a distance. The storm never really looked that intense on radar so I was under the impression that if it was a supercell that it would be towards the lower precipitation end of the spectrum.

[Jimmy Deguara]

Hi Michael Thomas,

I guess you gave in to easy:) Seriously if you have reasoning to believe it has supercell structure beyond the scope of radar imagery feel free to suggest. To really get an indication of what it is, we would require 3D radar scans. My only reaction here was to draw one's attention to the evidence given it was not very well explained and to react with caution. It is too easy to fall into the trap that others create. Perhaps using the term 'possible supercell' in this case perhaps is validated pending further investigation.

John, you suggest definitely there is a meso. What reasoning can you suggest to arrive at such conclusions?

I guess tornado observations be it landspout, gustnado variety, etc we can only speculate with limited information.

Regards,

Jimmy Deguara

[Michael Bath]

Brisbane soundings for 26th January 2007

00z / 12z


Links to GFS Analysis: Friday 26/01/2007 06z

Instability: CAPE / Lifted Index

Relative Humidity: 0300 / 0500 / 0600 / 0700 / 0850 / 1000

Temperature: 0300 / 0500 / 0700 /  0850 / 1000

Winds (knots): 0200 / 0300 / 0500 / 0600 / 0700 / 0850 / 0925 / 1000


Links to GFS Analysis: Friday 26/01/2007 12z

Instability: CAPE / Lifted Index

Relative Humidity: 0300 / 0500 / 0600 / 0700 / 0850 / 1000

Temperature: 0300 / 0500 / 0700 /  0850 / 1000

Winds (knots): 0200 / 0300 / 0500 / 0600 / 0700 / 0850 / 0925 / 1000

[nmoir]

Chasers need to be self critical and avoid the chinese whispers such was taking place on wz

I was talking to Jimmy on the past couple of chases about the idea of us developing a set storm report which will contain set parameters and information to make a chase report instead a general round up and a few pix which we do now. perhaps this is too restrictive but maybe it will make comparing different chasers reports of a single storm more useful as data.

personally  , though with my limited knowledge , i suspect a nasty micrburst and some swirly scud got a chaser or spotter excited then they called the BOM
The BOM got hammered after the Sydney Hail storm so i wonder if it was a bit of arse covering releasing the Tornado warning

[Jimmy Deguara]

John,

Hopefully your changes do not affect the validity of my questions - that is against the rules really:)

Otherwise, I would not mind gathering some reasoning to support your thoughts? We certainly have statements - but not much reasoning.

Regards,

Jimmy Deguara

[David Brodrick]

This report from the ABC quotes a BOM forecaster who said they had reports of hail to 20cm in size (yikes!). If that is true then surely is says something about the storm being highly organised and probably super-cellular?

Regards,
  Dave

[David C]

Yes, 20 cm hail would require a special set of conditions indeed and, while probably not without precedent (largest I am aware of is around 19cm which fell in/around Aurora NE a few years back), would not occur with any of the storms in the environment we are talking about.

The hail report might have been logged by the same person as the tornado report (XXXX might have been the root cause), but more likely was just a misquote (ie 20mm).

[Jimmy Deguara]

David, your post above talks about some interesting scenarios and problems with warnings but little is said in regards to what you think about the validity of the tornado warning itself and reasoning.

I would not mind gathering your thoughts about whether you feel this is a supercell and also providing some reasoning be it radar or from a visual perspective.

Regards,

Jimmy Deguara