881  
FXUS65 KFGZ 191154  
AFDFGZ  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE FLAGSTAFF AZ  
454 AM MST SAT JUL 19 2025  
   
SYNOPSIS  
FOR TODAY, THE BEST CHANCES FOR SHOWERS AND  
THUNDERSTORMS WILL BE EAST OF INTERSTATE 17 AND SOUTH OF  
INTERSTATE 40, WITH MORE ISOLATED STORM ACTIVITY FORECAST  
ELSEWHERE. LOW GRADE MONSOON CONDITIONS ARE FORECAST TO PERSIST  
INTO NEXT WEEK, WITH THE GREATEST STORM CHANCES OVER THE HIGHER  
TERRAIN FROM FLAGSTAFF EASTWARD.  
 
 
   
DISCUSSION  
NORTHERN ARIZONA REMAINS SANDWICHED BETWEEN A 500 MB  
LOW CENTERED OVER SOUTHERN CALIFORNIA AND A BROAD 500 MB HIGH  
CENTERED OVER TEXAS. SOUTHERLY FLOW BETWEEN THESE FEATURES  
CONTINUES TO ADVECT TROPICAL MOISTURE INTO THE STATE, BUT WITH A  
NOTICEABLE MOIST-EAST TO DRY-WEST ORIENTED GRADIENT THAT WILL  
LARGELY DICTATE THE CHANCES FOR SHOWERS AND THUNDERSTORMS THIS  
AFTERNOON.  
 
FOR TODAY, THE BEST CHANCES FOR SHOWERS AND THUNDERSTORMS WILL BE  
EAST OF INTERSTATE 17 AND SOUTH OF INTERSTATE 40, WITH MORE  
ISOLATED STORM ACTIVITY FORECAST ELSEWHERE. WHERE THE GREATEST  
MOISTURE EXISTS, MARGINAL CAPE BETWEEN 100-500 J/KG IS FORECAST.  
ESPECIALLY IN THIS AREA, STORMS WILL BE SLOW MOVING, SO FLASH  
FLOODING WILL BE THE PRIMARY THREAT. HOWEVER, BETWEEN 25-35 KTS OF  
DEEP LAYER SHEAR IS ALSO FORECAST. THIS IMBALANCE WILL MAKE IT  
DIFFICULT FOR BUILDING STORMS TO REMAIN INTACT, BUT FOR THOSE THAT  
DO SURVIVE, A FEW MORE POWERFUL ROTATING STORMS ARE POSSIBLE  
TODAY AS WELL. SO, ISOLATED, SEVERE STORMS CANNOT BE COMPLETELY  
RULED OUT.  
 
ACTIVE, BUT LOW GRADE MONSOON CONDITIONS ARE FORECAST TO CONTINUE  
INTO EARLY NEXT WEEK, WITH THE GREATEST STORM CHANCES OVER THE  
HIGHER TERRAIN FROM FLAGSTAFF EASTWARD. AROUND THE MIDDLE OF NEXT  
WEEK, THE GENERAL MODEL CONSENSUS SHOWS THAT A DEEP LOW WILL  
BECOME ESTABLISHED OFF THE WEST COAST, FORCING THE SUBTROPICAL  
HIGH AND TROPICAL MOISTURE PLUME EASTWARD, LEADING TO A DOWNTREND  
IN STORM ACTIVITY. THAT SAID, CONSIDERABLE SPREAD EXISTS, AND SOME  
MODEL SOLUTIONS KEEP THE STATE ENTRENCHED IN ENOUGH MOISTURE FOR  
A CONTINUATION OF LOW GRADE MONSOON ACTIVITY THROUGH THE WEEK.  
 
 
   
AVIATION...SATURDAY 19/12Z THROUGH SUNDAY 20/12Z  
ISOLATED TO  
SCATTERED SHOWERS AND THUNDERSTORMS BETWEEN 18Z AND 03Z, WITH THE  
BEST CHANCES FOR STORMS ALONG THE EASTERN MOGOLLON RIM AND WHITE  
MOUNTAINS. WINDS LIGHT AND VARIABLE, OR TERRAIN DRIVEN, IN THE  
MORNING, BECOMING SW 5-15KTS WITH GUSTS TO 20KTS AFTER 18Z. BRIEF  
MVFR VISIBILITIES AND GUSTY WINDS POSSIBLE NEAR THUNDERSTORMS.  
 
OUTLOOK...SUNDAY 20/12Z THROUGH TUESDAY 22/12Z...ISOLATED TO  
SCATTERED THUNDERSTORMS POSSIBLE EACH DAY BETWEEN 18Z AND 03Z.  
WINDS SW-W 5-15KTS WITH GUSTS TO 20KTS DURING THE DAY. LIGHT AND  
VARIABLE, OR TERRAIN DRIVEN, WINDS OVERNIGHT. BRIEF MVFR  
VISIBILITIES AND GUSTY WINDS POSSIBLE NEAR THUNDERSTORMS.  
 
 
   
FIRE WEATHER...SATURDAY AND SUNDAY  
ISOLATED TO SCATTERED SHOWERS  
AND THUNDERSTORMS ARE EXPECTED EACH AFTERNOON AND EVENING, MOST  
NUMEROUS OVER THE EASTERN MOGOLLON RIM AND WHITE MOUNTAINS.  
LOCALIZED WETTING RAINS AND GUSTY/ERRATIC OUTFLOW WINDS ARE LIKELY  
IN THE VICINITY OF STORMS. AWAY FROM STORMS, DAYTIME WINDS  
WEST/SOUTHWEST AT 5-10 MPH WITH GUSTS TO 10-20 MPH. EXPECT  
SEASONABLY COOL TEMPERATURES AND DAILY MINIMUM RH 15-30%.  
 
MONDAY THROUGH WEDNESDAY...ISOLATED TO SCATTERED SHOWERS AND  
THUNDERSTORMS EACH AFTERNOON/EVENING, WITH THE BEST CHANCES OVER THE  
EASTERN MOGOLLON RIM AND WHITE MOUNTAINS. DAYTIME WINDS  
WEST/SOUTHWEST AT 5-10 MPH WITH GUSTS TO 10-20 MPH. OTHERWISE,  
THE FORECAST CALL FOR SEASONABLY COOL TEMPERATURES AND DAILY  
MINIMUM RH 15-30%.  
 
 
   
FGZ WATCHES/WARNINGS/ADVISORIES  
NONE.  
 
 
 
 
 
PUBLIC...RR  
AVIATION...RR  
FIRE WEATHER...RR  
 
FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT  
WEATHER.GOV/FLAGSTAFF  
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