2017-01-15 EVENT: TX

[Ben Holcomb]

Seems like the possibility of a deep south Texas tornado event on Sunday. I have been watching the evolution of this system for almost the past week, and models (GFS and NAM) have been consistent with a strong, negatively tilted shortwave blowing through Mexico and TX on Sunday with a warm/moist warm sector ahead of it.

Trends have been further south than original models (which had us chasing almost to the Red River) but some things have remained consistent - a pretty moist (dewpoints >60F) albeit small warm sector ahead of the dryline with a northeast moving low. The dryline was showing rapid eastward propagation in earlier GFS runs, but the 12Z NAM today seems to back off on that, holding it consistently near the US/Mexico border.

I am seriously considering a run south on Sunday.

Here is a sounding from Uvalde, TX at 23Z Sunday.

 

[Ben Holcomb]

Not much changed in my thinking after looking at 00Z data this evening. The area west of San Antonio towards the Mexican border still looks great for supercells and possibly tornadoes on Sunday. Brownsville 00Z raob still shows a very moist environment in the lowest 2km, almost perfect even in the spring time with mixing ratio of 15.

Going to evaluate tomorrow and likely pull the trigger, positioning Saturday night into Texas to depart to the San Antonio area and west early Sunday afternoon.

 

[Ben Holcomb]

12Z NAM doesn't look much different today. WV showing very strong cutoff low crossing the Baja California into Mexico, which should emerge into the warm sector sometime in early to mid afternoon tomorrow.

Still a bit concerned about too much firing at once. Lots of lift as the system turns almost 45degrees negatively tilted, not a lot of capping, especially after 21Z. CAPE should still make it between 1000-1500 J/KG, especially north/northeast of Del Rio.

Morning soundings today look decent with mixing ratios of 12 or above in the DRT/BRO/CRP soundings with steepening lapse rates out west. In particular, the El Paso sounding looked very good in terms of winds as they were starting to feel the effects of that shortwave.

Still liking the south end of hill country for a tornado or two tomorrow. I will be leaving Norman tonight and heading south to setup for tomorrow.