Tuesday, May 18, 2010

May 20, 2010

This looks like a great day! A classic setup of supercells, likely tornadic, is on tap. After looking at things, I can say that this day is the one I would desperately love to chase.

Moisture - it'll be there. The dewpoints in the low 60s are already close by, and here's the 925 mb dewpoint forecast:



Instability - there's an impulse coming in at 500 mb:



The lapse rates will provide for serious CAPE:



Lift - how about the convergence along, say, a warm front and/or dryline?



Shear - check it out. Plenty.



And the best part? The storms aren't going to be cooking along:



All this points to a very chaseable day. SPC has issued a moderate risk and they might keep it thus; however, with all these ingredients coming into focus I believe a high risk isn't out of the question. The only caveat would be the storm mode: whereas tornadic supercells are possible, the more likely outcome is HP supercells, given the modest low-level shear. Kick that up a bit, even locally, and there's a bad/good day tomorrow.

My initial virtual chase target is west of Oklahoma City, say about Weatherford. (I've typed *that* location a few times here!) As storms develop I expect a couple to dominate, and if they interact with either the dryline or the warm front, magical things could happen. Heck, there'll likely be enough helicity in general to cause a few spinny things. Oklahoma City watch out!

2 comments:

  1. Dave..

    What is your assessment for thunderstorm potential next week in southern Manitoba? Right now it looks like good shear will be present, but instability could be weak. I'm thinking a messy thunderstorm complex situation will develop, what do you think?

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  2. Yeah, it looks pretty messy indeed, most of the week. However, and of course this is 228 hours away as of this writing, next Thursday has some potential. Naturally, we'd have to actually get the moisture in here that the GFS is painting, but with that kind of warm front setup and the shear the GFS is painting, it could be pretty awesome! So right now keep an eye on Thursday for good ones, but all week for any kind of rumbles.

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