901  
FXUS65 KPSR 220501  
AFDPSR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PHOENIX AZ  
1000 PM MST FRI FEB 21 2025  
   
UPDATE
 
 
UPDATED AVIATION  
 

 
   
SYNOPSIS
 
 
WARM, DRY, AND TRANQUIL WEATHER WILL PREVAIL THIS WEEKEND WITH  
TEMPERATURES CONTINUING TO RANGE AROUND 8 TO 10 DEGREES ABOVE  
NORMAL. AN ANOMALOUSLY STRONG RIDGE OF HIGH PRESSURE IS EXPECTED TO  
BUILD OVER THE DESERT SOUTHWEST SUNDAY, REACHING PEAK STRENGTH BY  
THE MIDDLE OF NEXT WEEK. THIS PATTERN WILL RESULT IN HIGHS  
APPROACHING THE LOWER 90S, OR NEAR RECORD TERRITORY ACROSS THE LOWER  
DESERT COMMUNITIES TUESDAY THROUGH THURSDAY.  
 

 
   
DISCUSSION
 
 
THIS WEEKEND, DETERMINISTIC MODELS AND ENSEMBLE MEMBERS SHOW A  
STEADY WARMING TREND AS A PATTERN SHIFT FROM NW FLOW ALOFT TO UPPER  
LEVEL RIDGING TAKES SHAPE. ON SATURDAY, ANOTHER WEAK DISTURBANCE  
WILL PROGRESS THROUGH THE AREA BUT WILL RESULT IN LITTLE TO NO  
CHANGE TO OUR WEATHER CONDITIONS AS TEMPERATURES REMAIN AROUND 8 TO  
10 DEGREES ABOVE AVERAGE. RIDGING OVER THE EASTERN PACIFIC WILL THEN  
SHIFT EASTWARD, ENCOMPASSING MUCH OF THE DESERT SOUTHWEST ON SUNDAY.  
THIS WILL RESULT IN HIGHS MAINLY REACHING INTO THE LOWER 80S ACROSS  
THE LOWER DESERTS SUNDAY AFTERNOON.  
 
H5 HEIGHTS WILL CONTINUE TO RISE ABOVE 580 DAM LATE SUNDAY INTO  
MONDAY WHICH WILL PROMOTE A SIGNIFICANT WARM UP ACROSS THE ENTIRE  
REGION EARLY NEXT WEEK. NBM FORECAST TEMPERATURES ARE STILL SHOWING  
MID 80S MONDAY, AND MOSTLY THE UPPER 80S STARTING TUESDAY. A FEW  
LOCATIONS ACROSS THE WESTERN DESERTS WILL LIKELY SEE THEIR FIRST 90  
DEGREE READING OF THE YEAR ON TUESDAY AFTERNOON, WHICH WOULD BE  
AROUND A MONTH EARLIER THAN NORMAL. THE MOST LIKELY TIMEFRAME FOR 90  
DEGREE HIGHS IN SOUTH-CENTRAL AZ INCLUDING THE PHOENIX METRO STILL  
LOOKS TO BE WEDNESDAY-THURSDAY. DURING BOTH OF THESE DAYS, HIGHS  
COULD REACH RECORD LEVELS AT PHOENIX SKY HARBOR (CURRENT CHANCES OF  
REACHING RECORD HIGHS AT 40-60%).  
 

 
   
PREVIOUS DISCUSSION
 
 
MODEL GUIDANCE IS STILL SHOWING A POTENTIAL SHIFT IN THE WEATHER  
PATTERN LATE NEXT WEEK AS A PACIFIC LOW IS LIKELY TO DEVELOP AND  
APPROACH THE WEST COAST AT SOME POINT BETWEEN NEXT THURSDAY AND  
SATURDAY. TIMING AND TRACK DIFFERENCES AMONG THE ENSEMBLES MAKE IT  
TOO DIFFICULT TO KNOW WHAT IS EXACTLY IN STORE FOR OUR REGION, BUT  
GUIDANCE OVERALL FAVORS THE LOW TRACKING THROUGH OUR REGION AT SOME  
POINT NEXT WEEKEND. FOR NOW, MOISTURE AVAILABILITY WITH THE SYSTEM  
LOOKS TO BE FAIRLY LOW, SO ANY PROSPECTS FOR RAIN IS ALSO LOW. WE  
SHOULD HOWEVER AT LEAST SEE A COOLING TREND BY NEXT WEEKEND, BUT SO  
FAR NBM GUIDANCE INDICATES TEMPERATURES WILL REMAIN ABOVE NORMAL.  
 

 
   
AVIATION
 
UPDATED AT 0500Z.  
 
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT; AND  
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:  
 
NO WEATHER CONCERNS WILL EXIST THROUGH SATURDAY NIGHT UNDER CLEAR  
SKIES. TRENDS IN WIND SPEEDS AND DIRECTIONS WILL BE NEARLY IDENTICAL  
TO THE PAST 24 HOURS WITH THE TYPICAL WESTERLY SHIFT IN THE PHOENIX  
METRO EARLY/MID AFTERNOON, WHILE N/NW DIRECTIONS WILL PREVAIL THE  
MAJORITY OF THE PERIOD IN SE CALIFORNIA.  
 

 
   
FIRE WEATHER
 
 
WARM AND DRY CONDITIONS WILL PERSIST THROUGH THE WEEKEND WITH STRONG  
HIGH PRESSURE QUICKLY BUILDING INTO REGION BY SUNDAY. EXPECT BREEZY  
CONDITIONS AGAIN THIS AFTERNOON ACROSS PORTIONS OF SOUTHEAST  
CALIFORNIA INTO THE LOWER CO RIVER VALLEY BEFORE OVERALL LIGHT WINDS  
ARE SEEN STARTING SATURDAY. LOW HUMIDITIES WILL CONTINUE DURING THE  
PERIOD WITH MINRHS MAINLY BETWEEN 10-15% AND FAIR TO POOR OVERNIGHT  
RECOVERIES TO AROUND 25-30%. UNSEASONABLY WARM TEMPERATURES ARE THEN  
FORECAST FOR NEXT WEEK WHILE DRY CONDITIONS PERSIST.  
 

 
   
CLIMATE
 
 
RECORD HIGH TEMPERATURES NEXT WEEK:  
 
DATE PHOENIX YUMA EL CENTRO  
---- ------- ---- ---------  
FEB 24 91 IN 1904 93 IN 1986 92 IN 1986  
FEB 25 92 IN 1921 95 IN 1986 94 IN 1986  
FEB 26 91 IN 1986 96 IN 1986 95 IN 1986  
FEB 27 92 IN 1986 95 IN 1986 96 IN 1986  
FEB 28 89 IN 1986 97 IN 1986 92 IN 1986  
 

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

 
 

 
 
DISCUSSION...SALERNO  
PREVIOUS DISCUSSION...KUHLMAN  
AVIATION...18  
FIRE WEATHER...KUHLMAN  
CLIMATE...18  
 
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