720  
FXUS65 KFGZ 171652  
AFDFGZ  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE FLAGSTAFF AZ  
952 AM MST THU JUL 17 2025  
   
SYNOPSIS  
AN ACTIVE MONSOONAL PERIOD IS FORECAST THROUGH  
FRIDAY, WITH SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS  
EXPECTED TODAY AND TOMORROW. LOW GRADE MONSOON CONDITIONS THEN  
SET IN FOR THE WEEKEND AND INTO NEXT WEEK, WITH ISOLATED TO  
SCATTERED STORMS POSSIBLE EACH DAY. COOLER TEMPERATURES ARE ALSO  
EXPECTED THROUGH THE REST OF THE WEEK AND INTO NEXT WEEK.  
 
 
   
DISCUSSION...TODAY  
MONSOONAL MOISTURE REMAINS PLACE TODAY,  
LEADING TO ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS THIS  
AFTERNOON. HOWEVER, DEBRIS CLOUDS FROM OVERNIGHT CONVECTION MAY  
LEAD TO A DELAYED START TO THE ACTIVITY. AS A RESULT, COVERAGE  
LOOKS TO BE LESS THAN PREVIOUSLY THOUGHT, WITH MORE SCATTERED  
COVERAGE OF STORMS EXPECTED THIS AFTERNOON.  
 
STORMS LOOK TO INITIALLY FORM JUST SOUTH OF THE MOGOLLON RIM, WHERE  
DESTABILIZATION IS EXPECTED TO TAKE PLACE INITIALLY. WITH 0-6 KM MEAN  
WIND FROM THE SOUTH, STORM ARE THEN EXPECTED TO MOVE NORTHWARD  
THROUGH THE AFTERNOON AS INSTABILITY INCREASE ACROSS THE REMAINDER  
OF THE REGION. STORM MOTION OF 5-15 KTS AND PWATS 0.80-1.10" WILL  
GENERALLY LEAD TO A FLASH FLOOD RISK GOING INTO THIS AFTERNOON.  
HOWEVER, SOME WEAK 0-6 KM SHEAR (~20-30 KTS) AND POCKETS OF MODEST  
CAPE (800-1000 J/KG) COULD ALLOW FOR A COUPLE STRONG TO SEVERE  
STORMS THIS AFTERNOON.  
 
FRIDAY...A WEAK TROUGH OVER THE NORTHERN BAJA EJECTS OFF THE PACIFIC  
AND MOVES INTO ARIZONA. THIS WILL LEAD TO AN INCREASE IN LARGE SCALE  
ASCENT OVER THE REGION, AIDING IN STORM DEVELOPMENT. HOWEVER, HI-RES  
GUIDANCE DOES CONTINUE TO BACK OFF ON THE OVERALL COVERAGE ON  
FRIDAY. AS A RESULT, MORE SCATTERED COVERAGE LOOKS TO BE MOST  
PROBABLE. GIVEN THE INFLUENCE OF THE TROUGH, A FEW STRONGER STORMS  
MAY BE POSSIBLE, AND POTENTIALLY BRING HAIL AND STRONG WINDS. FLASH  
FLOODING STILL LOOKS TO BE THE PRIMARY THREAT HOWEVER.  
 
SATURDAY THROUGH WEDNESDAY...THE AFOREMENTIONED TROUGH LOOKS TO MOVE  
INTO THE MOJAVE DESERT OVER THE WEEKEND, AND EVENTUALLY BECOME  
ABSORBED INTO WEAK LONGWAVE TROUGH OVER THE NORTHWESTERN US. THIS  
LOOKS TO USHER IN DRIER AIR TO NORTHERN ARIZONA, WITH FLOW NOT  
EXACTLY SUPPORTIVE OF MONSOONAL MOISTURE ADVECTION. LARGE-SCALE  
ENSEMBLE GUIDANCE STILL SHOWS THE VAST MAJORITY OF MEMBERS  
SUPPORTING A DOWNWARD TREND IN PWATS THROUGH AT LEAST THE MIDDLE OF  
NEXT WEEK. WHILE STORMS DO NOT LOOK TO ENTIRELY DISAPPEAR, COVERAGE  
LOOKS TO BE MORE ISOLATED. THE GREATEST ODDS FOR STORMS LOOK TO  
MAINLY BE OVER THE HIGHER TERRAIN INTO NEXT WEEK, ESPECIALLY ACROSS  
THE MOGOLLON RIM AND WHITE MOUNTAINS.  
 
 
   
AVIATION...THURSDAY 17/18Z THROUGH FRIDAY 18/18Z  
SCATTERED TO  
WIDESPREAD -SHRA/-TSRA BEFORE 02Z, WITH LINGERING -SHRA THROUGH  
08Z. BRIEF MVFR CONDITIONS AND GUSTY, ERRATIC WINDS POSSIBLE IN  
AND AROUND THUNDERSTORMS. OTHERWISE, VFR CONDITIONS WITH DAYTIME  
WINDS SOUTHWEST AT 5-15 KTS.  
 
OUTLOOK...FRIDAY 18/18Z THROUGH SUNDAY 20/18Z...ISOLATED TO SCATTERED  
SHRA/TSRA EACH DAY, MAINLY BETWEEN 19Z-02Z. BRIEF MVFR CONDITIONS  
AND GUSTY, ERRATIC WINDS POSSIBLE IN AND AROUND THUNDERSTORMS.  
OTHERWISE, VFR CONDITIONS WITH DAYTIME WINDS WEST TO SOUTHWEST AT  
5-15 KTS.  
 
 
   
FIRE WEATHER...TODAY AND FRIDAY  
SCATTERED SHOWERS AND  
THUNDERSTORMS ARE EXPECTED EACH AFTERNOON AND EVENING. WETTING  
RAINS, GUSTY OUTFLOW WINDS, AND FLASH FLOODING WILL BE POSSIBLE.  
DAYTIME WINDS WEST/SOUTHWEST 5-10 MPH WITH GUSTS 10-20 MPH EACH DAY.  
 
SATURDAY THROUGH MONDAY...SCATTERED TO ISOLATED SHOWERS AND  
THUNDERSTORMS ARE EXPECTED OVER THE WEEKEND AND ON MONDAY, WITH THE  
GREATEST ODDS OVER THE EASTERN MOGOLLON RIM AND WHITE MOUNTAINS.  
WETTING RAINS ARE LIKELY WITHIN ANY STRONGER STORMS. DAYTIME WINDS  
WEST/SOUTHWEST 5-10 MPH WITH GUSTS 10-20 MPH EACH DAY. GUSTY,  
ERRATIC WINDS POSSIBLE IN AND AROUND THUNDERSTORMS.  
 
 
   
FGZ WATCHES/WARNINGS/ADVISORIES  
NONE.  
 
 
 
 
 
PUBLIC...HUMPHREYS  
AVIATION...MCCOLLUM  
FIRE WEATHER...HUMPHREYS  
 
FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT  
WEATHER.GOV/FLAGSTAFF  
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