ZCZC SPCSWOMCD ALL
ACUS11 KWNS 160350 
SPC MCD 160350 
AZZ000-160445-

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 

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