Mesoscale Discussion 1530
   NWS Storm Prediction Center Norman OK
   1050 PM CDT Sun Aug 15 2021

   Areas affected...south-central AZ

   Concerning...Severe potential...Watch unlikely 

   Valid 160350Z - 160445Z

   Probability of Watch Issuance...5 percent

   SUMMARY...The risk for severe gusts may continue as a thunderstorm
   cluster moves to the west-southwest from eastern AZ and approaches
   the greater Phoenix metro over the next few hours.

   DISCUSSION...Radar imagery from KPHX shows a cluster of intense
   thunderstorms in a relatively optimized balance for renewed
   thunderstorm development on surging outflow.  The 00z Phoenix raob
   showed relatively steep low to mid-level lapse rates.  Surface
   cooling has been tempered this evening due to rich low-level
   moisture (14 g/kg lowest 100 mb mean mixing ratio)---limiting the
   lessening of low-level lapse rates.  Furthermore, the 25-kt flow in
   the 3-6 km layer per the raob will support storm movement to the
   west-southwest and perhaps augment wind potential with evaporative
   cooling.  As a result, it is plausible severe gusts move into the
   eastern part of the Phoenix metro during the next 1-2 hours as this
   activity continues west-southwestward before eventually weakening.

   ..Smith/Bunting.. 08/16/2021

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

   ATTN...WFO...TWC...FGZ...PSR...

   LAT...LON   33681227 33951101 33111037 32681146 32941226 33681227