Mesoscale Discussion 0754
   NWS Storm Prediction Center Norman OK
   0301 PM CDT Thu May 28 2020

   Areas affected...Galveston Island and adjacent upper Texas coast
   vicinity

   Concerning...Severe potential...Watch unlikely 

   Valid 282001Z - 282200Z

   Probability of Watch Issuance...20 percent

   SUMMARY...Isolated severe thunderstorm development, including
   supercells, may continue across upper Texas coastal areas
   near/southwest of Houston through 4-5 PM.

   DISCUSSION...Sustained supercell development, which initiated a
   couple of hours ago along the sea-breeze inland of Galveston Bay,
   has maintained considerable intensity and organization, including a
   strong low-level mesocyclone, while propagating southward across
   Galveston Bay.  This cell has probably been enhanced by increasing
   deep-layer shear associated with the approach of a digging 35-40 kt
   northwesterly 500 mb jet.  

   Low-level flow and shear are weak, but winds veer with height, and
   inflow of seasonably moist boundary layer air with large CAPE
   (2000-4000+ J/kg) has maintained intense updrafts.  Although some
   recent weakening of low-level rotation has been evident, there
   probably is some potential for re-intensification as the cell
   approaches Galveston between now and 20-21Z.  Latest objective
   analysis, however, suggests that strongest low-level convergence
   remains focused across coastal areas north of Galveston Island,
   near/southwest of Texas City, where intense new convective
   development may be underway.  This may become the more prominent
   convection, and could still pose a localized risk for hail, strong
   wind gusts and perhaps a tornado.

   ..Kerr/Hart.. 05/28/2020

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

   ATTN...WFO...HGX...

   LAT...LON   29439524 29589487 29339456 29099494 29179522 29439524