Friday, June 21, 2019

Isolated Strong Storms This Evening; SPC Says No Watch Anticipated

The National Weather Service (NWS) Storm Prediction Center (SPC) has identified areas of central, southern and western Texoma with a chance of a few strong to severe thunderstorms this evening, however no weather watch is anticipated.

Late this afternoon the NWS SPC put out this updated highlighting the area where rather isolated strong to severe thunderstorms are expected.  At the same time they stated that the chance of a severe weather watch was at 5%.  In other words a weather watch is highly unlikely at this time for tonight, Friday, June 21, 2019.

Here's the latest information from the NWS SPC:








   Mesoscale Discussion 1179
   NWS Storm Prediction Center Norman OK
   0455 PM CDT Fri Jun 21 2019

   Areas affected...portions of western and southwestern Texas

   Concerning...Severe potential...Watch unlikely 

   Valid 212155Z - 220000Z

   Probability of Watch Issuance...5 percent

   SUMMARY...Isolated storms that manage to develop may pose a risk for
   very isolated large hail or damaging wind gusts. Given the isolated
   nature of the threat, a WW issuance is not expected.

   DISCUSSION...Isolated discrete convection has attempted to initiate
   in proximity to a near-stationary dryline, from SNK to far northern
   Mexico (just south of the Terrell County border). These storms are
   developing in a region of relatively mediocre deep-layer shear, but
   with modest buoyancy immediately along the dryline (given a very
   hot, deeply mixed boundary layer extending up to 700 mb per latest
   RAP forecast soundings). Steep lapse rates are in place (over 9 C/km
   in the lowest 3 km, with 8 C/km mid-level lapse rates), suggesting
   that any storms that can develop will have intense updrafts capable
   of producing severe hail. Given the deep, very dry boundary layer in
   place, significant evaporative cooling would promote damaging wind
   gusts with well-defined downdrafts. 

   Convergence along the dryline, however, is quite weak, with
   upper-level support lacking across the area. As such, there is
   considerable uncertainty as to how many storms can initiate and
   sustain themselves long enough to promote severe potential. A small
   area of relatively greater convergence along the dryline is evident,
   and this is where further development will most likely occur. Given
   the expected sparse coverage of the severe threat, a WW issuance is
   not anticipated.

   ..Squitieri/Kerr.. 06/21/2019

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

   ATTN...WFO...OUN...EWX...SJT...LUB...MAF...



[Im hoping to continue my forecasting and severe weather safety sharing all the way into 2020, but I need your help.  If you could donate a dollar or two it would be a great help.  I appreciate it.  Thank you so much, Bryan.]

Stay tuned through the weekend as there is a much more significant risk of severe weather in the area on Saturday and Sunday.  Updates will be posted soon.

Meteorologist Bryan Rupp