990  
FXUS65 KFGZ 041813  
AFDFGZ  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE FLAGSTAFF AZ  
1113 AM MST SUN MAY 4 2025  
   
SYNOPSIS
 
A LARGE AREA OF LOW PRESSURE WILL BRING COOLER  
TEMPERATURES AND INCREASED CHANCES FOR PRECIPITATION TODAY THROUGH  
WEDNESDAY. WARM AND DRY WEATHER FORECAST TO RETURN THURSDAY ONWARD.  
 

 
   
DISCUSSION
 
A DEEP AND COLD UPPER LOW (FOR MAY) IS NOW NEAR PALM  
SPRINGS AND WILL MOVE EASTWARD TODAY AND TONIGHT, BEFORE SLOWING  
DOWN AND SPLITTING ON MONDAY. THE LOW THEN RECONSOLIDATES NEAR THE  
FOUR CORNERS MONDAY NIGHT AND TUESDAY, WHILE FILLING AND WARMING. A  
TRAILING LOW MOVES INTO THE TROUGH POSITION OVER ARIZONA ON  
WEDNESDAY.  
 
THIS IS A COMPLICATED PATTERN, WITH MANY DIFFERENT ASPECTS TO LOOK  
AT. CONVECTION AHEAD OF THE LOW TODAY MAY PRODUCE A FEW STRONGER  
THUNDERSTORMS, WHILE PRECIPITATION TONIGHT MAY ENHANCE ALONG A COLD  
FRONT. THEN, WRAPAROUND PRECIPITATION AFFECTS THE AREA MONDAY AND  
MONDAY NIGHT, WITH CONVECTIVE ELEMENTS CONTINUING INTO TUESDAY. THE  
TRAILING LOW WILL MOVE INTO A MOIST AIR MASS WEDNESDAY, WITH MORE  
POTENTIALLY SIGNIFICANT CONVECTION BREAKING OUT.  
 
ADDITIONALLY, WE WILL HAVE GUSTY PRE-FRONTAL WINDS TODAY, BUT OUR  
RELATIVE HUMIDITY LEVELS AND WIND SPEEDS AVOIDS THE NEED FOR ANY  
HEADLINES. SNOW LEVELS IN THE CORE OF THE LOW LATER TONIGHT AND  
MONDAY WILL PRODUCE AREAS OF SNOW ABOVE 6500-7500 FEET, WITH A FEW  
BRIEF TROUBLE SPOTS POSSIBLE FROM FLAGSTAFF WESTWARD.  
 
WHEN THIS IS ALL SAID AND DONE, MANY AREAS THROUGH WESTERN AND  
CENTRAL ARIZONA MAY SEE QPF AMOUNTS FROM 1-2". ANOTHER LATE SEASON  
GIFT THAT MAY ALLOW US TO AVOID A DANGEROUS FWX SEASON BEFORE THE  
MONSOON ARRIVES IN LATE JUNE.  
 
ALL THIS IS COVERED IN THE CURRENT PACKAGE, WE WILL EXAMINE SNOW  
LEVELS A BIT CLOSER THIS AFTERNOON PACKAGE. NO SHORT TERM UPDATES  
NEEDED.  
 

 
   
AVIATION...SUNDAY 04/18Z THROUGH MONDAY 05/18Z
 
SHRA/TSRA WILL  
INCREASE ACROSS THE AREA THROUGH THE PERIOD. MVFR POSSIBLE IN  
HEAVIER SHOWERS THROUGH THIS EVENING. AFTER AROUND 09Z, AREAS OF  
MORE STEADY RA AND HIGH ELEVATION SN (ABOVE 6500-7000 FT MSL) ARE  
FORECAST ALONG/WEST OF A KPGA-KGCN-KFLG-KPRC LINE. WIDESPREAD  
MVFR, AND AREAS OF IFR/LIFR ARE EXPECTED IN THIS AREA. WINDS  
S 10-20 KTS WITH GUSTS 25-35 THROUGH 02Z, THEN LESS THAN 10 KTS.  
GUSTY AND RAPIDLY CHANGING WIND ARE POSSIBLE NEAR SHOWERS.  
 
OUTLOOK...MONDAY 05/18Z THROUGH WEDNESDAY 07/18Z...CONTINUED  
AREAS OF -SHRA/-SHSN AND SOME ISOLATED -TSRA THROUGHOUT THE  
PERIOD, WITH THE HIGHEST COVERAGE THROUGH 12Z WED. WIDESPREAD MVFR  
WITH AREAS IFR/LIFR THROUGH TUESDAY MORNING, THEN AREAS MVFR.  
WINDS SW 10-15 KTS MONDAY, THEN W-SW 5-10 KTS TUE/WED. GUSTY AND  
RAPIDLY CHANGING WIND ARE POSSIBLE NEAR SHOWERS.  
 

 
   
FIRE WEATHER...TODAY THROUGH MONDAY
 
COOLER WITH SHOWERS AND  
THUNDERSTORMS AT TIMES. ACCUMULATING SNOW POSSIBLE ABOVE 6500-7000  
FEET LATE TONIGHT AND MONDAY. SOUTHERLY THROUGH SOUTHWEST WINDS  
INCREASING TO 15 TO 20 MPH, WITH GUSTS TO 25 TO 35 MPH TODAY.  
SOUTHWEST WINDS DECREASE TO 10 TO 15 MPH ON MONDAY.  
 
TUESDAY THROUGH THURSDAY...COOL AND SHOWERY WEATHER CONTINUES  
TUESDAY, WITH DECREASING COVERAGE WEDNESDAY. BECOMING DRY AND MUCH  
WARMER THURSDAY. SOUTHWEST THROUGH WEST WINDS 10 TO 15 MPH TUESDAY.  
WINDS MORE WEST-NORTHWESTERLY ON WEDNESDAY, LIGHT AND VARIABLE TO  
NORTHEAST ON THURSDAY.  
 

 
   
FGZ WATCHES/WARNINGS/ADVISORIES
 
NONE.  
 

 
 

 
 
PUBLIC...PETERSON  
AVIATION...JJ  
FIRE WEATHER...JJ  
 
FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT  
WEATHER.GOV/FLAGSTAFF  
 
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