Tuesday, July 13, 2010

Non-Chasing Forecast for 7/14

The terrain is going to be a big bummer on this one, and the vast differences on main operational models are also a bit troubling. Anything south of the MN/IA border should be linear pretty quickly. Given extreme instability and unseasonably strong flow, a tornado can't be ruled out in Iowa, but I think it would be a fairly isolated and embedded event given more veered flow in this area.

While it's a fairly wide target, I do see a region that does stand a chance at a localized tornado event tomorrow assuming the NAM and WRF are correct. My somewhat large target box would be along a Minneapolis to Rochester line, and then east to a Tomah to Eau Claire WI line. Chasing that area of Wisconsin will be a real treat, so one's best hope is probably to try and get something early before things get into the god awful terrain near the Mississippi river in far eastern Minnesota. I think anything significant should be along and north of Interstate 90.

Eventually training/congealing will likely lead to congealment into an MCS. If I didn't have plans here in northern IL til mid-afternoon I would probably venture out to far SE Minnesota (Faribault, MN - if I had to pick a target city) just to get in a nice July chase, but this will probably save me some frustration. I just think the terrain on this one will be a bigger day ruiner than the actual setup itself.

Now if you're siding with the GFS, tomorrow looks like an absolute wash. No surface flow, and completely unidirectional flow above that. With all that instability and no real directional or speed shear, you'll end up with a big multi-cell cluster that does a whole lot of gusting out. I think the NAM solution is a little more likely, but it's something to keep in mind tomorrow.

I guess I'll just hope that something inexplicably fires in southern WI or NW Illinois that I can play with. Don't count on that one though. My best bet is lightning after dark this far east.

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