SPC AC 120537

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1137 PM CST Tue Dec 11 2018

   Valid 121200Z - 131200Z

   ...NO SEVERE THUNDERSTORM AREAS FORECAST...

   ...SUMMARY...
   Thunderstorms are expected to develop across portions of southwest
   Texas today and portions of southeast and east Texas into the lower
   Mississippi Valley Wednesday night.

   ...Synopsis...
   A positive-tilt shortwave trough will migrate eastward from Baja
   California, reaching south Texas by 10Z Thursday while taking on
   negative tilt.  Meanwhile, a more powerful shortwave initially over
   Idaho will amplify dramatically while migrating southeastward toward
   the Texas South Plains, with impressive 200+ dm 500 hPa height falls
   across that region during the forecast period.  At the surface, a
   low will organize across southeastern Colorado and migrate
   southeastward toward western north Texas overnight.  Low-level warm
   advection ahead of the low will result in 50s F dewpoints reaching
   the Red River in Texas and low-60s F dewpoints across southeast
   Texas.  Areas of thunderstorms are expected to develop across west
   Texas today and eastward into portions of Arkansas and Louisiana
   overnight.

   ...Southeast Texas...
   Models suggest that thunderstorms should increase overnight in
   response to moistening low levels and lift associated with the
   advancing southern-stream mid-level trough.  Strengthening wind
   profiles should support updraft rotation with any
   persistent/organized cellular convection, although weak instability
   (250-600 J/kg MUCAPE) rooted just above the boundary layer within
   the pre-convective environment suggest that convection will likely
   remain slightly elevated.  At this time, the severe threat appears
   to be too low for even 5%/Marginal probabilities, but will increase
   if higher dewpoints can reach the Texas coast - most likely after
   the end of the forecast period.

   ..Cook/Peters.. 12/12/2018

   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z