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9th Annual National Storm Chaser Convention - Day 2

Storm Chaser Convention - February 17th, 2007 UPDATE CONTINUES!

We left early from Erie, CO and drove down to the Convention's location at the Radisson Hotel in Aurora CO. The roads were clear, the traffic light. This is a remarkable contrast to yesterday where strong winds brought ground blizzards, and wet heavy snow to the front range.

Now we begin: A complete day of all things weather.

Blogging continues...


After the morning Break recap:

The first presentation was Dr Greg Forbes from the Weather Channel to give his recap on the 2006 Tornado Season, and to give a forecast of what he predicts the 2007 season to be. The 2006 Tornado season was 11 - 13% below average but the number of death (66) were above average. Off peak periods were extremely active. Prime Time periods see a down ward trend perhaps as a result of global warming.

Missouri, IL & TN demonstrated record hits. In fact Tornado outbreaks occurred futher east than usual due to unfavorable upper air patterns. Dr Forbes' 2007 prediction is for tornado outbreaks in E TX and Central NE.

Mike Umscheid gave the second presentation on the Oct 26 SW KS event aka Tumbleweed convergence. Mike is based in Dodge City, KS and gave a fascinating insight into forecasting, analysis, and chase decision. The forcast for Oct 26 was not promising and Mike explained in some detail why tornado potential looked minimal. However by noon on Oct 26 events on the ground appeared more promising, and Mike decided this was a good opportunity to chase. The Oct 26th outbreak was characterized by cold core, low CAPE, low capped convection.


After a brief 15 minute break the presentations continued.

Next we had Tim Marshall on Chase Cases 2006: What went wrong? This was a great funny presentation by Tim on his dismal 2006 Chase Season. It was heartening for me to see that even the experienced chasers may have chase busts. Mother Nature Rules. There are 5 important points that I got out of Tim's presentation:
1. Check the Data and Check it Often - so often Kevin and I just don't do this.
2. Remember it is still a mystery why some events present tornadoes and why some don't. - No matter how sophisticated we are in our forecasting models etc, Mother Nature still Rules.
3. Guessing the cap strength still remains a major problem- there is so much we still don't know.
4. Watch your back - otherwise known as turn around and look at what is going on behind you.
5. Still fun to chase marginal events. - Just because something looks marginal doesn't mean that it is not fun to chase.
And Lastly,
6. Chasing is fun, and the learning opportunities are endless, even when chases are a bust.

Next we had Jon Davies give a presentation on Cold Core Systems.
I found this very interesting as Jon highlighted some of the characteristics of Cold Core Systems:
Here are a few:
1. Look for a closed 500mb Low and a surface Low N to NE
2. Look for boundary intersection (may be a subtle boundary.)
3. Dewpoints lower to mid 50's
4. Lower range CAPE's can produce cold core Tornado's. Most RUC models only have CAPEs from 500 J/Kg so they will not pick up below 500. Check surface CAPES to get an idea of where the lower CAPE's may be.

Also Jon Davies has more about these characteristics on his website. (When I have some time I will post a link to that.)

After Jon Davies' presentation, we breaked for lunch. Kevin and I decided to forego the expensive looking hotel food and find a fast food cheapo place nearby. We navigated our way out of the hotel and found a subway off Parker Rd. Coming back was more problemmatic, as the sign posting for the hotel is not clearly marked, you think you are going off on the 225 off ramp, but the hotel access is cunningly disguised. Not good.

After Lunch presentations were good, and informative. We started off with the 100 year search for the red sprite. This was dvd presentation about sprites, elves and other storm top phenomena. Apparently there is quite a bit of activity occuring above storm tops that project 20 to 30 km into space.

Dr Josh Wurman was next with a presentation on a study of low level winds of tornado's and the effects on urban environments. The study of the lowest levels of a tornado are not widely understood or documented largely due to the fact that mobile radars cannot see close to the ground. Dr Wurman explained how they attempted to map low level winds by extrapolating from pressure readings. But this was not "real" data. The Tornado Intercept Vehicles (mad crazy looking things out of a Mad Max movie) ran tornados and storms in order to get "real" data. From these data collections managed to create low level wind models. Then took actual recorded tornado tracks (with low level wind speeds) and tracked them across urban environments such as Chicago. Purpose of analysis was to see what extent of property and human damage would have occurred. Found some interesting data suggesting that greater property damage results from higher population densities coupled with type of construction. Higher population densities may also lead to increased probability of fatalities (POF.) The data seemed to suggest a POF of around 10%. What does this mean? Apart from demonstrating the potential deadliness of tornados through accident of time and place, I don't think this meant very much. Dr Wurman then went on to talk about tornado science and how to move science up to the next level. This I found more interesting. In order for there to be value in science, studies need to more directed towards understanding the why's. Why do some storms create Tornados and others don't? Dr Wurman argues that at present hard science has been lacking. Right now we have case studies, but no hard science that require repeatability and generality.

Dr Wurman disclosed some preliminary findings of such a study by Curtis Alexander (no relation) which attempted to find the climatology of tornados by examining over 100 tornado studies. The preliminary results were surprising:
1. There is no relationship between Tornado size and intensity
2. Weak Tornados are rare, moderate strength (F2/ EF3) are more common
3. Most Tornados have a typical size of between 200 to 350 m across.

The next speaker was Dan McCarthy on Tornado Trends in the USA. Tornado fatalities are trending downwards due to increased technology, media connectivity and communications and more eyes on the ground. However public awareness during off peak times was lower, and he suggested leads to more fatalities, than during the high peak periods. He suggested that Weather Service needs to do a better job at educating the public that tornados do occur during the off peak times (Oct through Dec.) The discussion afterwards focused on what exactly needs to be communicated to the public. What to do with the information. Also issues of construction techniques built to withstand tornados was also discussed.

After Dan McCArthy we had an excellent presentation by Dr Howie Bluestein. I love his presentations. He showed DOW images of a number of tornados. He was also very amusing at showing some unexpected tornado sightings which he had without his radar.

It was about here that Kevin and I started to fade. Since lunch time we had had no breaks. We decided to give the next 2 speakers a miss. They were Al Pietrycha on The Spotter Network, and Steve Hodanash on Colorado Lightning Casualties (according to the agenda). I am sure both presentations were excellent. I just needed to relax, and mellow out before the Banquet and video session tonight.

As I write this we are unwinding in our Hotel room waiting for the 5:45 when our banquet is scheduled to begin.