This looks to be on the edge between a total non-event and a decent winter setup for west Texas. The big question (as usual) is whether or not sufficient moisture will arrive in time for there to be sufficient instability. As of the 12Z models, the NAM predicts 1000-1500 J/kg extending all the way through S and W TX up to around Lubbock and points slightly north. However, the GFS and SREF have minimal CAPE for the same area. I seem to recall lately that the models have been underdoing the amount of moisture return that actually occurs in time for these events (see 2011-11-07 and 2012-01-22 as recent examples). Given that the front currently sinking across the SGP isn't going to clear the TX coast and will leave a pool of moist air in S TX leading up to this event, I don't think it's unreasonable to think that the models are underdoing the moisture for this event, too.
At the upper levels this system contains some pretty good looking wind fields. WSWly 500 mb winds exceeding 50 kts over a widespread area over due south 850 mb winds in association with the formation of a seasonably strong LLJ gives really high shear in the area. There looks to be sufficient shear for supercells perhaps as far south as the Lamesa latitude.
At the upper levels this system contains some pretty good looking wind fields. WSWly 500 mb winds exceeding 50 kts over a widespread area over due south 850 mb winds in association with the formation of a seasonably strong LLJ gives really high shear in the area. There looks to be sufficient shear for supercells perhaps as far south as the Lamesa latitude.
