2014-03-21 FCST: TX/OK

[Jeremy Perez]

An isolated, marginal chance for a severe storm or two may take place on Friday.

Sixty degree dew points will have made their way northward into Texas and Oklahoma. Some of the limited moisture will be beneath the southern branch of split flow with 40-50 Kt at 500 mb. For the last three days or so, GFS has been plotting a small area of 750 to possibly 1000 j/kg along the dryline/cold front near the Red River at 00Z. And now that NAM is in range, it's picking that up too.

Bulk shear of 40-50 kts are currently showing up south of the Red River on both NAM and GFS. Winds are veering with height, but weak surface flow is plotting Hobbit-sized curves on forecast hodographs. NAM is also showing inverted-V profiles on Skew-T, compared to GFS. Cap is breakable, but while GFS shows precipitation breaking out along the cold front and northern edge of the dryline, NAM isn't currently interested in letting anything through except for northeast Oklahoma.

So, the more I look at it, the more pessimistic it seems. With no upper level troughing, weak surface flow (around 10 kts), limited moisture, even what's currently there may disappear. Still, I'm in the neighborhood for the next few day, and will be keeping an eye on it as an opportunity for a non-tornadic chase—perhaps an opportunity for brief structure on a storm before it gusts out, maybe a dusk lightning show.

 

[Zack Cooper]

Friday actually has a little bit of potential in NW TX. small area of 60's dewpoints with CAPE values nearing 1000 j/kg possible in the evening along a decently sharp dryline feature. Hodographs are decent and soundings look supportive of severe weather developing. If I was considering chasing I would be looking in the Wichita Falls area, but given I chased this most recent marginal setup, not even gonna consider this one. Still, will be interesting to see if a supercell or two can develop in that area, as it could have a slight tornado potential.

 

[Zack Hargrove]

In my opinion, the 60 degree dewpoints are making their way much further north on the GFS than is realistic. The Euro and NAM would agree with me on that, and its not abnormal to see the GFS way too bullish with moisture. The NAM barely gets the 60 degree contour further north than Houston. I don't see how there is any tornado potential, personally... if the dews are, in fact, over forecast by the GFS (which is the most likely scenario) then LCLs are going to be way up there. There may be a marginally severe hailer with the nice lapse rates, but I wouldn't expect much.

 

[Zack Cooper]

Ultimately it will depend on the moisture return up into that area. Even with elevated storms, they could produce brief structure and some hail. NAM though, like you said, has lower dewpoints than the GFS with 50's across that area and also, less favorable wind profiles.