487  
FXUS65 KPSR 241700  
AFDPSR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PHOENIX AZ  
1000 AM MST THU APR 24 2025  
   
UPDATE
 
 
UPDATED AVIATION  
 

 
   
SYNOPSIS
 
 
TEMPERATURES WILL REMAIN SEASONABLY WARM FOR THE NEXT COUPLE DAYS. A  
DRY WEATHER SYSTEM WILL INFLUENCE THE REGION THIS WEEKEND, BRINGING  
BREEZY TO LOCALLY WINDY CONDITIONS AND COOLING TEMPERATURES INTO THE  
UPPER SEVENTIES TO AROUND EIGHTY DEGREES FOR A DAY OR TWO ACROSS THE  
LOWER DESERTS. EXPECT A WARMING TREND EARLY NEXT WEEK, WITH  
TEMPERATURES LIKELY RETURNING TO NEAR SEASONAL NORMALS BY TUESDAY.  
 

 
   
DISCUSSION
 
 
EARLY MORNING MID-LEVEL WATER VAPOR IMAGERY AND 500 MB RAP ANALYSIS  
REVEAL WSW FLOW ALOFT OVER MUCH OF THE SOUTHWEST US, WITH A WEAK  
SHORTWAVE MAKING ITS WAY INTO THE INTERMOUNTAIN WEST AND A MORE  
POTENT N-S ELONGATED UPPER LEVEL TROUGH OVER THE EAST PACIFIC. AS  
THE EAST PACIFIC TROUGH APPROACHES THE WEST COAST LATE WEEK, BECOMES  
A CLOSED LOW, AND MOVES EASTWARD THROUGH THE GREAT BASIN OVER THE  
WEEKEND, THE WEATHER WILL TURN MORE UNSETTLED. HOWEVER, FOR THE NEXT  
COUPLE DAYS, EXPECT A CONTINUATION OF MOSTLY TRANQUIL CONDITIONS  
WITH SEASONABLY WARM TEMPERATURES AND TYPICAL AFTERNOON BREEZINESS.  
HIGHS TODAY AND FRIDAY WILL GENERALLY REACH THE UPPER 80S TO LOWER  
90S ACROSS THE LOWER DESERTS (SLIGHTLY COOLER OUT WEST ON FRIDAY, IN  
THE MIDDLE 80S.)  
 
THE PRIMARY IMPACTS FROM THE APPROACHING UPPER LEVEL LOW WILL BE  
BREEZY TO LOCALLY WINDY CONDITIONS AND ELEVATED TO NEAR CRITICAL  
FIRE WEATHER CONCERNS. THE HEIGHT FALLS FROM THIS SYSTEM WILL RESULT  
IN A TIGHTENING OF THE REGIONAL PRESSURE GRADIENT AND THUS ENHANCED  
BREEZINESS BEGINNING ON FRIDAY ACROSS PORTIONS OF SOUTHEAST CA,  
SPREADING EASTWARD THROUGH AZ ON SATURDAY. IN FACT, NAEFS/EPS MEAN  
700 MB WIND SPEEDS EXCEED THE 90TH PERCENTILE OF CLIMATOLOGY  
STATEWIDE ON SATURDAY. THE ENHANCED BREEZINESS WILL LINGER INTO  
SUNDAY ACROSS THE EASTERN AZ HIGHER TERRAIN AREAS. EARLY INDICATIONS  
ARE THAT WIDESPREAD GUSTS BETWEEN 25-35 MPH WILL BE COMMON, WITH  
LOCALLY HIGHER GUSTS UPWARDS OF 40+ MPH ACROSS THE WIND PRONE AREAS  
OF IMPERIAL COUNTY AND THE AZ HIGH TERRAIN. ALONG WITH THE WINDS AND  
ASSOCIATED FIRE WEATHER CONCERNS, A SECONDARY IMPACT FROM THIS  
SYSTEM WILL BE A COOLDOWN AS THE LATEST NBM INDICATES TEMPERATURES  
FALLING A GOOD 5-10 DEGREES BELOW NORMAL STARTING ON SATURDAY ACROSS  
THE WESTERN DESERTS AND THEN SPREADING EASTWARD THROUGH SOUTH-  
CENTRAL AZ ON SUNDAY. AFTERNOON HIGHS ARE LIKELY TO ONLY REACH THE  
UPPER 70S TO AROUND 80F.  
 
A WARMING TREND WILL COMMENCE EARLY NEXT WEEK, AS ENSEMBLES  
ADVERTISE THE CLOSED LOW WEAKENING AND THE BULK OF THE SYSTEM'S  
ENERGY EJECTING NORTHEASTWARD. MUCH OF THE WESTERN CONUS IS EXPECTED  
TO FALL UNDER THE INFLUENCE OF A BROAD AREA OF HIGH PRESSURE, THOUGH  
A SLIGHT COMPLICATION TO THE TEMPERATURE FORECAST WILL BE THE  
POTENTIAL FOR A FEW WEAK CUTOFF LOWS TO LINGER/MOVE OVER THE  
SOUTHWEST US NEXT WEEK. REGARDLESS, THE FORECAST AREA SHOULD REMAIN  
COMPLETELY DRY THROUGH AT LEAST THE NEXT 7 DAYS, AND TEMPERATURES  
WILL WARM BACK TO NEAR SEASONAL LEVELS AS EARLY AS TUESDAY AND WELL  
INTO THE 90S DURING THE MIDDLE TO LATTER HALF OF THE UPCOMING  
WORKWEEK.  
 

 
   
AVIATION
 
UPDATED AT 1700Z.  
 
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, KDVT; AND  
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:  
 
NO MAJOR WEATHER CONCERNS WILL EXIST THROUGH FRIDAY MORNING UNDER  
PERIODS OF SOME PASSING HIGH CIRRUS DECKS. TRENDS IN THE TIMING OF  
DIRECTIONAL WIND SHIFTS WILL BE SIMILAR TO THE PAST 24 HOURS WITH  
SPEEDS SOMEWHAT WEAKER AND GUSTINESS LESS PRONOUNCED TODAY. HOWEVER,  
A FEW LATE AFTERNOON/EVENING GUSTS 20-25KT WILL STILL BE POSSIBLE  
ACROSS SE CALIFORNIA TERMINALS. STRONGER WINDS WILL FREQUENT GUSTS  
WILL BE LIKELY FRIDAY AFTERNOON AND EVENING.  
 

 
   
FIRE WEATHER
 
 
DRY CONDITIONS WILL PERSIST THROUGH THE NEXT 7 DAYS, WITH SEASONABLY  
WARM TEMPERATURES THROUGH THE END OF THE WORKWEEK. EXPECT DIURNALLY  
DRIVEN AND GENERALLY LIGHT WINDS TODAY, WITH TYPICAL AFTERNOON  
UPSLOPE BREEZINESS. AN APPROACHING LOW PRESSURE SYSTEM LATE WEEK  
INTO THIS WEEKEND WILL INCREASE WINDS FRIDAY FOR THE WESTERN  
DISTRICTS AND AREAWIDE BY SATURDAY, LEADING TO LOCALLY ELEVATED TO  
NEAR CRITICAL FIRE WEATHER CONDITIONS FOR THE TYPICALLY PRONE AREAS,  
SUCH AS THE ARIZONA HIGH TERRAIN EAST OF PHOENIX. TEMPERATURES WILL  
ALSO COOL BELOW NORMAL THIS WEEKEND AS A RESULT OF THE LOW PRESSURE  
SYSTEM. AFTERNOON MINRHS WILL GENERALLY FALL INTO THE UPPER SINGLE  
DIGITS TO LOWER TEENS THROUGH THE END OF THE WORKWEEK BEFORE RISING  
SLIGHTLY THIS WEEKEND, IN THE MIDDLE TO UPPER TEENS, THANKS TO THE  
COOLER TEMPERATURES. OVERNIGHT RECOVERIES WILL BE POOR TO FAIR,  
GENERALLY BETWEEN 25-45% THROUGH FRIDAY NIGHT, INCREASING TO 30-50%  
FOR THE EASTERN DISTRICTS BY SATURDAY NIGHT AND SLIGHTLY HIGHER (45-  
60%) FOR THE WESTERN DISTRICTS.  
 

 
   
PSR WATCHES/WARNINGS/ADVISORIES
 
 
AZ...NONE.  
CA...NONE.  
 

 
 

 
 
DISCUSSION...WHITTOCK  
AVIATION...18  
FIRE WEATHER...WHITTOCK  
 
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