Storm Prediction Center Mesoscale Discussion 2282

   Mesoscale Discussion 2282
   NWS Storm Prediction Center Norman OK
   1023 AM CST Thu Dec 26 2024

   Areas affected...The Texas Coastal Plain into East Texas

   Concerning...Severe potential...Tornado Watch likely 

   Valid 261623Z - 261900Z

   Probability of Watch Issuance...80 percent

   SUMMARY...The severe thunderstorm threat is expected to steadily
   increase through the late morning and afternoon as the environment
   becomes more favorable for robust convection. Watch issuance is
   anticipated in the coming hours to address this threat.

   DISCUSSION...Open warm sector convection has been steadily
   increasing in both coverage and depth over the past hour across the
   TX Coastal Plain into southeast TX with a few deeper cells beginning
   to reach sufficient depth for steady lightning production. Recent
   surface observations show the early stages of surface cyclogenesis
   across north TX with an attendant increase in southeasterly winds
   and a steady northwestward progression of low-level moisture.
   Despite extensive cloud cover, mid-60s dewpoints, combined with 7-8
   C/km mid-level lapse rates, should promote MLCAPE values increasing
   into the 1000-2000 J/kg range by early afternoon. Coincidentally,
   the low/mid-level mass response associated with the deepening
   surface low should promote increasing low-level SRH and deep-layer
   wind shear that should promote supercellular storm modes within the
   open warm sector. As such, the expectation is that the developing
   convection should continue to slowly deepen and intensify through
   early afternoon with an attendant increase in the overall severe
   threat. Exact timing of when convection will become sufficiently
   intense to warrant watch issuance remains uncertain (though a watch
   will likely be needed by early-afternoon), but given the potential
   for supercellular tornadoes, including significant tornadoes, a
   tornado watch will likely be needed.

   ..Moore/Thompson.. 12/26/2024

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

   ATTN...WFO...LCH...SHV...HGX...FWD...EWX...

   LAT...LON   30019407 29059582 29059627 29169666 29389700 29959715
               30379710 31759498 31789449 31599419 31169395 30799378
               30479374 30259380 30019407