300  
AWUS01 KWNH 121521  
FFGMPD  
AZZ000-UTZ000-NVZ000-CAZ000-122100-  
 
MESOSCALE PRECIPITATION DISCUSSION 1023  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
1120 AM EDT WED AUG 12 2026  
 
AREAS AFFECTED...SOUTHERN NV...SOUTHWESTERN UT...NORTHERN AZ  
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE  
 
VALID 121519Z - 122100Z  
 
SUMMARY...SHOWERS AND THUNDERSTORMS DEVELOPING IN AN ANOMALOUSLY  
MOIST AIRMASS ARE EXPECTED TO INCREASE IN COVERAGE THROUGH THE  
LATE MORNING INTO THE EARLY AFTERNOON HOURS, WITH THE HEAVIEST AND  
SLOWER MOVING STORMS POSSIBLY RESULTING IN SOME INSTANCES OF FLASH  
FLOODING THROUGH 21Z.  
 
DISCUSSION...CONVECTION IS STEADILY INCREASING ACROSS NORTHWESTERN  
ARIZONA LATE THIS MORNING WITH PLENTY OF MONSOONAL MOISTURE IN  
PLACE ACROSS THE REGION. PWS ARE GENERALLY ON THE ORDER OF 1.2 TO  
1.8 INCHES ACROSS WESTERN PORTIONS OF THE OUTLOOK AREA FROM THE  
LATEST SPC MESOANALYSIS, COUPLED WITH AMPLE INSTABILITY GIVEN  
500-1000 J/KG MIXED LAYER CAPE. THIS SHOULD INCREASE INTO THE  
1000-1500 J/KG RANGE LATER THIS AFTERNOON, AND THIS SHOULD FUEL  
MORE WIDESPREAD CONVECTION ACROSS MUCH OF NORTHERN ARIZONA AND  
EXTENDING INTO SOUTHWESTERN UTAH. THERE IS CURRENTLY A GREATER  
CONCENTRATION OF STORMS JUST TO THE NORTH OF A 850 MB TROUGH  
ACROSS WEST-CENTRAL PORTIONS OF ARIZONA.  
 
THE CURRENT CAM GUIDANCE SUITE IS INDICATING THE POTENTIAL FOR  
PATCHY QPF MAXIMA OF 1-3 INCHES THROUGH 21Z THIS AFTERNOON, WITH  
THE GREATEST FOCUS LIKELY TO BE OVER THE NORTHWESTERN QUADRANT OF  
ARIZONA. SOME INSTANCES OF FLASH FLOODING WILL BE POSSIBLE WHERE  
THE MORE PERSISTENT AND SLOW MOVING CONVECTION DEVELOPS,  
ESPECIALLY ACROSS BURN SCARS, ARROYOS, OR OTHER VULNERABLE TERRAIN  
AREAS.  
 
HAMRICK  
   
..PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT
 
 
ATTN...WFO...FGZ...PSR...SLC...VEF...  
 
ATTN...RFC...RSA...STR...NWC...  
 
LAT...LON 38431316 37561249 36701207 35861118 35001017  
33911054 33401190 33381326 33801423 34921454  
36011499 37411490 38281431  
 
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