Topic: Tornado Alley Chasing

[Peter J]

Jimmy

When you go to the US (Tornado Alley) for your annual chase, how many tornadoes do you normally find each year on average, and have you encountered an EF5 storm?

PJ

[Jimmy Deguara]

Hi Pete,

The variation in the number of tornadoes can be quite significant and also depends on the length of time you go for. I can say that I have seen 39 tornadoes over 7 years - say on average 5 tornadoes per year? However, one year namely 2004 produced about 20 tornadoes - the previous year only 1 very brief tornado on the last day I was there!

I also would not go for numbers. A good quality highly photogenic tornado far outweighs a low contrast wedge wrapped in rain. I have chased the Greensburg tornado 2007 but really I did not see it with my own eyes - concentrating on data when others in the car saw it with the lightning flash. I have it on video which makes it a consolation prize I guess. The damage survey from this was well worth it and humbling.

I would also think about going to the US for other unique components. The majestic supercell that carves up the countryside over there are quite spectacular and full of energy as well. The structures on some occasions just leave you breathless!
I hope this helps.

Regards,

Jimmy Deguara

[Mike]

Jimmy, just on the supercell issue.  We've seen the massive supercells on videos and docos, but from the massive supercells you have witnessed and chased, can you give some indication of the length in miles that one in particular stretched that really blew you away for its shear size?  Perhaps the Oklahoma supercell comes to my mind from a previous thread, but in terms of mileage how far did you chase whilst having this supercell in view the whole time and over what time period?

It would be a very worthwhile piece of information indeed for those of us that have not witnessed big storms as you have seen.

Mike

[Jimmy Deguara]

Hi Mike,

For shear size, yes the Oklahoma supercell 29th May 2004 comes up there with the largest I have ever seen. I mean this was because I was mostly staring at the mesocyclone but we were not on it for an extremely long period of time - perhaps 2 to 3 hours at most but on the beat - moving along. We did not take this storm lightly given it was producing hail larger than baseballs and possibly up to 5 inches in diameter, tornadoes were spinning up rapidly and the inflow strength was violent - you needed a leopard tank to hold down the tripod! All in all, this storm had a track taking it through a chasable 9 hour history and would have taken you into Missouri - the next state around 2am if you were that keen!

Report here:
http://www.australiasevereweather.com/storm_news/2004/docs/200405-03.htm

Possibly the most exciting chase of all time that was non-tornadic was the inflow dominant supercell "vaccum cleaner" 4th June 2003 in New Mexico. This storm we got onto reasonably late but when the structure evolved, it was incredible - it was like giant octopus - inflow bands from the south and southeast and east and at different levels. The inflow was so ferocious that the dust was being shrowded at the base of the supercell. The wind inflow was creating damage and took off the roof of a mobile home! Despite the storm being tornado warned, it was impossible to see the tornadoes if any were produced. The lightning during the eveninf and nighttime was virtually constant in cloud! What made this storm so incredible was it was one of the only storms where footage did not require much editing! Almost all of the material was used as it was so dynamic and so much was happening.

Check the report here:
http://www.australiasevereweather.com/storm_news/2003/docs/200305-03.htm

From a tornado perspective, I think I will place both White Deer 29th May 2001

Report on this page:
http://www.australiasevereweather.com/storm_news/2001/docs/200105-04.htm

and

http://www.australiasevereweather.com/storm_news/2004/docs/200405-01.htm

Both these events were just classic with a good road network to work with and the storm positioned basically perfectly. We were able to traverse the supercells, enjoy great structure, great contrast and several tornadoes. Both produced explosive supercells, and very large violent tornadoes (of course for us that only meant White Deer). We were also able to move with the storm at a resonable rate and with little visual distractions (trees).

The factors that affect the duration (be it time and distance) a person can be on a supercell depends on its life history (how long lived it is to sustain sufficiently interesting and chasable structure), the road network, the speed the supercell may be travelling, visibility (difficult terrain and landscape obstructions namely trees) and any impending danger (the chasers' safety). Of course in some cases road blocks can be an issue.

I guess from my perspective, if you can even be on a storm for 2 hours or more, you are doing well given the limiting factors. And also, are you talking one storm or an afternoon's chasing. Many chasers leave one supercell that could have been tornadic and head off to another that is about to become tornadic. So in effect, you may still be chasing but another storm.

Another component I find in Tornado Alley chasing is the cap often breaks closer to 6pm in strong cap situations and then the whole atmosphere explodes. This limits daytime chasing to 3 to 4 hours regardless. And then, the die hards can also go for lightning photography as well to try some interesting nighttime structure, possible tornado opportunities and lightning itself. That can last into the early hours of the morning if you are keen enough. Personally, these days I tend save my energy for the daytime chases and perhaps a couple of hours of lightning photography if it is half decent.

I hope this gives some insight.

Regards,

Jimmy Deguara