MESOSCALE DISCUSSION 1500
   NWS STORM PREDICTION CENTER NORMAN OK
   0257 PM CDT MON JUL 04 2011
   
   AREAS AFFECTED...S-CNTRL...CNTRL AND ERN AZ
   
   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 
   
   VALID 041957Z - 042100Z
   
   TSTM COVERAGE SHOULD GRADUALLY INCREASE THROUGHOUT THE AFTERNOON
   OVER THE HIGHER TERRAIN OF SERN/ERN AZ...WITH AN ACCOMPANYING
   POTENTIAL FOR DMGG WIND GUSTS AND HEAVY RAINFALL. A WW IS NOT
   CURRENTLY ANTICIPATED DUE TO THE EXPECTED ISOLD NATURE OF THE SVR
   THREAT...BUT CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED.
   
   VISIBLE SATELLITE LOOP TRENDS INDICATE GROWING TCU/CB FIELDS OVER
   THE MOGOLLON RIM AND HIGHER TERRAIN AREAS OF ERN/SERN AZ. RICH
   BOUNDARY LAYER MOISTURE IS IN PLACE ACROSS MUCH OF THE REGION
   /CHARACTERIZED BY PWAT VALUES OF 1.7-1.9 INCH PER GPS-PW SENSORS/
   AND IS SUPPORTING A RESERVOIR OF MLCAPE VALUES EXCEEDING 1000 J/KG
   OVER THE LOWER DESERTS. MEANWHILE...MCV FROM REMNANT CONVECTION OVER
   SONORA IS PROGRESSING NNW OVER THE GULF OF CA...AND POSSIBLY AIDED
   IN THE INITIATION OF AN ISOLATED STRONG TSTM OVER WRN PIMA COUNTY.
   CURRENT TRENDS ARE THAT ACTIVITY OVER THE SWRN AZ LOWER DESERTS
   SHOULD REMAIN ISOLATED OVER THE NEXT FEW HRS. 
   
   WITH TIME...INCREASING AREAL COVERAGE OF TSTMS OVER THE HIGHER
   TERRAIN OF E-CNTRL AND SERN AZ SHOULD GENERATE ONE OR MORE COLD
   POOLS THAT WILL PROPAGATE INTO THE LOWER DESERTS /WITH ESE MIDLEVEL
   FLOW NEAR 20 KTS IN THE 700-500 MB LAYER/. AS CINH CONTINUES TO
   ERODE WITH FURTHER HEATING...THE ENVIRONMENT SHOULD REMAIN
   SUPPORTIVE FOR ADDITIONAL CONVECTIVE DEVELOPMENT. THE PRIMARY THREAT
   WILL LIKELY BE WET DOWNBURSTS /OWING TO PRECIP LOADING/. CONVECTION
   SHOULD BE ABLE TO ORGANIZE INTO MULTICELL CLUSTERS WITH TIME OWING
   TO STRONGER THAN TYPICAL EFFECTIVE WIND SHEAR...BUT IT IS UNCLEAR IF
   AN ORGANIZED WIND THREAT WILL MATERIALIZE.
   
   ..ROGERS.. 07/04/2011
   
   
   ATTN...WFO...TWC...FGZ...PSR...
   
   LAT...LON   32171383 32651366 33901304 34381213 34681124 34501025
               33860935 33160918 31940923 31310966 31331105 32171383