Mesoscale Discussion 1581
   NWS Storm Prediction Center Norman OK
   0218 PM CDT Wed Aug 26 2020

   Areas affected...Extreme Southeast TX...Southern LA

   Concerning...Severe potential...Watch likely 

   Valid 261918Z - 262045Z

   Probability of Watch Issuance...95 percent

   SUMMARY...The tornado potential is increasing across the region and
   a Tornado Watch will be needed across portions of the area with in
   the next hour.

   DISCUSSION...Recent regional radar imagery has shown an increase in
   more cellular storms just north of the rain band stretching from
   extreme southeast TX across southern LA. Cells within this band have
   a deepening trend, particularly across extreme southeast TX. At the
   same time, the stronger low to mid-level flow associated with Laura
   continues to move northward. Recent LCH VAD data has shown increased
   wind speeds in the 1-3 km layer. This has resulted in stronger
   low-level shear as well as an increase in 0-1 km storm-relative
   helicity values across the region, particularly far southeast TX and
   adjacent southwest/south-central LA. Instability remains modest but
   there is no convective inhibition. All of these factors favor a
   gradually increasing potential for tornadogenesis. As such, a
   Tornado Watch will be needed within the next hour to cover this
   potential.

   ..Mosier/Bunting.. 08/26/2020

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

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

   LAT...LON   31489461 31489350 30649066 29419041 29329130 29909346
               29739434 31489461