ZCZC SPCSWOMCD ALL
ACUS11 KWNS 210135 
SPC MCD 210135 
AZZ000-210230-

MESOSCALE DISCUSSION 1864
NWS STORM PREDICTION CENTER NORMAN OK
0835 PM CDT TUE OCT 20 2015

AREAS AFFECTED...EASTERN/SOUTHERN AZ

CONCERNING...SEVERE THUNDERSTORM WATCH 514...

VALID 210135Z - 210230Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 514
CONTINUES.

SUMMARY...SEVERE POTENTIAL /MAINLY HAIL/ WILL CONTINUE TO DIMINISH
ACROSS MUCH OF EAST-CENTRAL AZ...SUCH THAT SEVERE THUNDERSTORM WATCH
514 WILL BE ALLOWED TO EXPIRE AT/BY 02Z. SOME STRONGER STORMS
CAPABLE OF HAIL/GUSTY WINDS COULD REDEVELOP/INCREASE ACROSS PARTS OF
SOUTH-CENTRAL/SOUTHEAST AZ LATE TONIGHT.

DISCUSSION...EARLIER STRONG TO SEVERE THUNDERSTORMS ACROSS
EAST-CENTRAL AZ HAVE GENERALLY DIMINISHED IN INTENSITY THROUGH EARLY
EVENING...AND THIS SAME WEAKENING TREND IS LIKELY TO CONTINUE VIA
FURTHER COOLING/DECOUPLING OF WHAT WAS ONLY A MODESTLY UNSTABLE AIR
MASS AS PER 00Z OBSERVED SOUNDINGS FROM FLAGSTAFF/TUCSON.
ACCORDINGLY...SEVERE THUNDERSTORM WATCH CAN EXPIRE AT 02Z.

LATER TONIGHT...OWING TO INCREASING FORCING FOR ASCENT RELATED TO AN
APPROACHING VORTICITY MAX OVER FAR NORTHWEST MEXICO/BAJA
VICINITY...STORMS SHOULD INCREASE IN COVERAGE/POSSIBLY INTENSITY
ACROSS SOUTH-CENTRAL/SOUTHEAST AZ. WHILE A FEW OF THESE STORMS COULD
PRODUCE MARGINALLY SEVERE HAIL/GUSTY WINDS THROUGH THE OVERNIGHT
HOURS...CURRENT THINKING IS THAT AN ADDITIONAL WATCH ISSUANCE IS
UNLIKELY.

..GUYER.. 10/21/2015

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

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

LAT...LON   34361070 35051039 34590921 31780922 31470997 31531150
            32251145 33201083 34361070 

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