Storm Prediction Center Mesoscale Discussion 2234

   Mesoscale Discussion 2234
   NWS Storm Prediction Center Norman OK
   1241 PM CST Mon Nov 18 2024

   Areas affected...east TX...western LA...and far southwest AR

   Concerning...Severe potential...Watch possible 

   Valid 181841Z - 182045Z

   Probability of Watch Issuance...60 percent

   SUMMARY...Increasing potential for a couple tornadic supercells
   should occur by late afternoon as warm-sector storms intensify ahead
   of a outflow-reinforced cold front. A tornado watch may be needed.

   DISCUSSION...As surface temperatures have warmed into the mid 80s as
   far northeast as the greater Houston Metro Area, warm-sector showers
   have deepened downstream within the warm conveyor across southeast
   TX. A 17Z sounding from Texas A&M at CLL well sampled the
   pre-frontal environment ahead of the outflow-reinforced cold front
   that has been marching east across east TX. While tropospheric lapse
   rates are weak, enhanced low-level shear persists where surface
   winds remain slightly backed ahead of the front (as shown in the 18Z
   LCH/SHV soundings). Surface winds/low-level flow have slowly veered
   farther southwest (where temperatures are warmer) per HGX VWP data,
   suggesting that initial storms might struggle to produce low-level
   mesocyclones until convection spreads farther northeast. The
   undercutting nature of the front will also limit tornado potential
   after passage. The more favorable kinematic/thermodynamic
   environment will probably become centered across the Sabine Valley
   in the next couple hours. This corridor will be monitored for a
   possible tornado watch.

   ..Grams/Smith.. 11/18/2024

   ...Please see www.spc.noaa.gov for graphic product...

   ATTN...WFO...LCH...SHV...HGX...

   LAT...LON   29619439 30039508 30969517 32139442 33149415 33439380
               33259302 32629270 31939266 30609282 29809328 29619439