Mesoscale Discussion 1706
   NWS Storm Prediction Center Norman OK
   0122 PM CDT Mon Sep 21 2020

   Areas affected...portions of the middle and upper Texas Coast

   Concerning...Severe potential...Watch unlikely 

   Valid 211822Z - 212045Z

   Probability of Watch Issuance...20 percent

   SUMMARY...A couple of brief tornadoes are possible through this
   evening across the middle and upper Texas coastal vicinity. A
   tornado watch does not appear likely at this time, given an overall
   marginally supportive environment. However, trends will continue to
   be monitored over the next several hours.

   DISCUSSION...Stronger bands associated with T.S. Beta will continue
   to move onshore near Galveston Bay of the next several hours. Radar
   imagery over the last 30-60 minutes has shows some modest mid-to-low
   level rotation in mini-supercells over the near-shore Gulf waters.
   Most of this activity has been weak, with rotational velocity
   signatures less than 20 kts. Overall, the environment appears only
   weakly supportive for tornadoes. MLCAPE has increased marginally
   along the coast, but is generally 500 J/kg or less. This is partly
   due to the cloud shield from Beta limiting insolation, but also
   partly due to lower surface dewpoints than would typically be
   expected along the Texas coast ahead of a landfalling tropical
   system. Low level shear has strengthened this afternoon, with VWP
   data from KHGX indicating around 200 m2/s2 0-1 km SRH when corrected
   for storm motion, though deep layer shear in only marginally
   supportive of supercells. Given the overall modest environment,
   expect weak supercell activity and associated waterspouts/tornadoes
   to be short-lived and transient.

   ..Leitman/Guyer.. 09/21/2020

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

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

   LAT...LON   28819516 28419575 28439610 28839642 29269641 29759582
               29959529 29969489 29679446 29359439 29109457 28819516