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Sunday, July 13, 2008

July 11th Frazee MN tornado in the trees

It was SO nice to have a day all to myself. I haven't done a real chase day alone for a long, long time. Cullen didn't want to make the trip as he thought the tornado chances were too low and in a bad area to spend the day weaving around lakes and dodging logging trucks. There were several times I wished I would have talked him into it as I kind of forgot how much there is to do solo and how much he does when we chase.

Anyhow, my full chase account can been seen and read HERE.

I thought this would be a no brainer to forecast. Get up to GFK (Grand Forks), find the warm front draping off to the southeast and pick the cell riding along it. I was pretty much dead on as the best tornado of the day occurred near Fosston to the east of Grand Forks. The sleeper of the day was the Willmar, MN. I was really surprised to have an EF3 in an environment which did not look conducive to tornadogenesis based on the models. Beau Gjerdingen posted the 0Z MPX launch data on F5chaser.com :
That definitely spells out a different scenario that what the models have forecasted...to a point. I have never been a big believer in instability compensating for wind support (not just low level shear) but maybe it is time to start throwing this into the mix of things I look at when forecasting a chase day. In the end I'll still use my original formula which is weighted towards low level shear, however I need to broaden my horizon and look at the potential for vorticity stretching with extremely explosive updrafts. Obviously the statistics will win out with the low level shear but check out this graphic courtesy of Brad Nelson:

Pretty amazing to see the data to support high CAPE does compensate for shear.

Anyhow, kudos to all the chasers (yes, even the SS guys...I'll bury the hatchet now) who scored the Willmar tornado and got the reports to the NWS office in Minneapolis. Well done.

Here is what I had to settle for "up nort". Ended up on a nice supercell from Rothsay Minnesota to just southwest of Park Rapids Minnesota. About 80 miles or so. Got really lucky as the cell flanked one of the few road options not totally obscured by trees, hills, and lakes. One advantage was I grew up in that area and knew the roads very well and which ones would offer a line of sight.



Time to turn the sights on mid week now.

1 comment:

Shane Adams said...

Congrats on the obscure, solo chase tornado. I live for those.

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