May 20, 2012

May 20 Target: Southern TX Panhandle/sw OK

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Thom and I just finished our "morning briefing". Our destination today will be somewhere in the area between Wichita Falls TX and Lubbock.
We plotted soundings from both the WRF-NAM and the RAP and get anywhere from 1700 to 2100 J/kg sbCAPE with virtually no CIN close to the quasi stationary frontal boundary. The hodographs are very interesting for that area. I've provided the one for Wichita Falls at 0000 UTC. And if you want to see both the sounding and the hodograph with all of the indices, that is here:

The weak 500 mb ground level flow belies the more than adequate 0-6 km AGL shear in the area...which with easterly or northeasterly winds at the surface creates really large loops in the hodographs. The "fly in the ointment" is the low level is virtually nonexistent in the forecasts.

What Happened

The dew points never quite made it up to the levels forecast in the morning model runs.  Also, there were some very interesting interactions between that boundary and the storms.  The richer moisture lay to the north of the boundary, yet when storms crossed the boundary they "croaked".   

Those to the south of the boundary were alive, but were drawing on the anemic moisture, and looked "CAPE starved" and had very high bases.   I created a panorama of one of the storms we observed, just south of Vernon TX.  It clearly was rotating, with mid-level cloud fingers extending into the updraft area.  And you can see an inflow tail to the right.  Yet, it never did much, besides producing 1 1/2" hail.  That's Thom and our vehicle to the right.