11/11/10 FCST: TX/OK

[Connor McCrorey]

I guess I'll start a thread now just to hear what some other people think.

DISCLAIMER: Being mid-November, I never thought I might get to chase on my birthday, so forgive me if I'm being a little overly-optimistic

I've been keeping an eye on Thursday for a little while now. I was starting to lose hope, but with the 18Z NAM, I'm a little more encouraged. With 60+ kt SW flow at 500mb and 25-30 kt SSE 850s providing 0-1 km SRH generally exceeding 100 m^2/s^2 across the TX panhandle, the biggest problem with this setup has been the lack of instability, as is to be expected this time of year. But the 18Z NAM, while just one model run, has bumped up both surface temperatures and dewpoints by at least a couple of degrees, increasing the potential instability to slightly less awful values.

I've always been a big instability kind of guy, but I'm reminded of 3/8/2010. Not that the setups are the same, but that it is very possible to get tornadoes (some significant) out of non-CC setups in this part of the country even with very limited instability.

 

[Bob Hartig]

I hope you get your birthday storm chase, Connor! But I have to say, it looks pretty marginal to me. Yes, the moisture picture appears to be much more optimistic this run, but 30 kt 0-6 km shear is pretty weak, and the 500 mb jet barely clips the richer moisture per the NAM.

I've been watching this system too. The GFS a few days ago piqued my interest because it wanted to move the H5 winds farther south, squarely over some decent moisture. Obviously the NAM is painting a different picture. For several reasons--shear, helicity, instability, shortened insolation--I think this system is going to need a kick in the pants to be a producer. I'm not ruling out what can happen between now and Thursday afternoon, just sayin'.

Addendum: Just checked out the GFS. It offers a somewhat rosier picture than the NAM with the juxtaposition of better shear over the Theta-e lobe. If it's closer to the solution, then SE/S central Oklahoma might fire up. Still pretty meager instability. It's November, after all.

 

[Connor McCrorey]

I'm eyeing the OK/TX border near I-40.

http://www.twisterdata.com/index.ph...iew=large&archive=false&sounding=y&sndclick=y

That's a decent looking hodo if you ask me, and the skew-t isn't awful. I mean yeah, steeper lapse rates would be nice, but a little bit of heating in that area could do wonders. Sfc-500mb bulk shear is about 50 kts in that area, and the NAM is even firing a little isolated precip blob FWIW.