429  
FXUS65 KPSR 081137  
AFDPSR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PHOENIX AZ  
437 AM MST SAT NOV 8 2025  
   
UPDATE  
12Z AVIATION DISCUSSION.  
 
 
   
KEY MESSAGES  
 
- UNSEASONABLY WARM TEMPERATURES WITH DRY CONDITIONS WILL PREVAIL  
THROUGH AT LEAST THE MIDDLE OF NEXT WEEK.  
 
- HIGH TEMPERATURES ACROSS THE LOWER DESERTS WILL PEAK SUNDAY AND  
MONDAY WITH SOME LOCAL DAILY RECORDS POSSIBLE.  
 
- A POTENTIAL COOL AND WET WEATHER PATTERN WILL ARRIVE INTO THE  
DESERT SOUTHWEST BY THE END OF NEXT WEEK.  
 
 
   
SHORT TERM /TODAY THROUGH MONDAY/  
 
AN OVERALL DRY AND BENIGN WEATHER PATTERN WITH UNSEASONABLY WARM  
TEMPERATURES WILL CONTINUE THIS WEEKEND AND INTO EARLY NEXT WEEK.  
LATEST IR SATELLITE IMAGERY AND OBJECTIVE ANALYSIS INDICATES  
UPPER-LVL RIDGING REMAINS FIRMLY IN PLACE OVER THE WESTERN CONUS.  
THIS RIDGE WILL CONTINUE TO BE THE PREDOMINANT FEATURE OVER THE  
NEXT SEVERAL DAYS. H5 HEIGHTS WILL RANGE FROM 582-584 DAM THIS  
AFTERNOON WHICH IS AROUND THE 90TH PERCENTILE OF CLIMATOLOGY FOR  
THIS TIME OF YEAR. THESE POSITIVE HEIGHT ANOMALIES WILL RESULT IN  
ANOTHER WARM AFTERNOON ACROSS OUR REGION WITH LOWER DESERT HIGHS  
TOPPING OUT IN THE MID TO UPPER 80S.  
 
THE UPPER-LVL RIDGE WILL BECOME MORE AMPLIFIED ACROSS THE WESTERN  
CONUS ON SUNDAY AS A DEEP TROUGH OF LOW PRESSURE DEVELOPS OVER THE  
GREAT LAKES/UPPER MIDWEST. IN RESPONSE, MODEL H5 HEIGHTS WILL  
RISE TO AROUND 588-590 DAM ACROSS THE DESERT SOUTHWEST WHICH IS  
NEAR THE CLIMATOLOGICAL MAXIMUM FOR EARLY NOVEMBER. AS A RESULT,  
HIGHS ACROSS THE LOWER DESERTS WILL CLIMB INTO THE UPPER 80S TO 90  
DEGREES. THE RECORD HIGH ON SUNDAY FOR PHOENIX SKY HARBOR IS 88  
DEGREES AND NBM PROBABILITIES ARE STILL HIGH (>70% CHANCE) THAT  
THE RECORD WILL BE BROKEN. ALTHOUGH THE RIDGE WILL WEAKEN SLIGHTLY  
ON MONDAY, POSITIVE HEIGHT ANOMALIES WILL STILL RESULT IN HIGHS  
REACHING WITHIN A DEGREE OR TWO OF DAILY RECORDS ACROSS THE LOWER  
DESERTS. DUE TO THESE WARM AFTERNOONS, A MINOR HEATRISK WILL  
EXIST FOR THOSE THAT ARE NOT CONDITIONED TO THE HEAT, SO IT IS  
IMPORTANT TO CONTINUE TO PRACTICE SMART HEAT SAFETY.  
 
 
   
LONG TERM /TUESDAY THROUGH SATURDAY/  
 
CONFIDENCE REMAINS HIGH THAT UPPER-LVL RIDGING WILL PREVAIL OVER  
THE DESERT SOUTHWEST THROUGH AT LEAST THE MIDDLE OF NEXT WEEK AS A  
TROUGH OF LOW PRESSURE TAKES AIM ON COASTAL CALIFORNIA AND THE  
PACIFIC NORTHWEST. UNDER THE PRESENCE OF RIDGING ALOFT, DAILY  
HIGHS ACROSS THE LOWER DESERTS WILL CONTINUE TO TOP OUT AROUND 5  
TO 8 DEGREES ABOVE NORMAL TUESDAY THROUGH THURSDAY. STARTING ON  
WEDNESDAY WE WILL ALSO SEE AN INCREASING FETCH OF HIGH CLOUDS  
PROGRESSING INTO OUR FORECAST AREA AHEAD OF THE APPROACHING TROUGH.  
 
DETERMINISTIC MODELS AND ENSEMBLE MEMBERS ARE NOW COMING INTO BETTER  
AGREEMENT SHOWING THE ONSHORE PROGRESSION OF THE UPPER TROUGH AND  
DISPLACEMENT OF THE UPPER RIDGE EWD INTO THE SOUTHERN PLAINS LATE  
NEXT WEEK. AS THIS OCCURS, A LARGE PLUME OF PACIFIC MOISTURE WILL  
BEGIN TO OVERSPREAD CA AND THE INTERMOUNTAIN WEST FROM THURSDAY INTO  
FRIDAY. THIS SYSTEM WILL LIKELY BRING WIDESPREAD MEASURABLE  
PRECIPITATION TO COASTAL AND INTERIOR CALIFORNIA. THE COMBINATION OF  
INCREASING MID-LVL SOUTHWESTERLY FLOW WILL TRANSPORT MOISTURE INTO  
THE DESERT SOUTHWEST BY FRIDAY INTO SATURDAY AND THAT IS WHEN WE  
WILL SEE RAIN CHANCES INCREASE FROM W TO E ACROSS OUR FORECAST AREA.  
THERE ARE STILL SUBTLE DIFFERENCES IN TIMING IN MODEL QPF FIELDS,  
HOWEVER MOST MEMBERS ARE NOW SHOWING MEASURABLE RAINFALL IN  
SOUTHCENTRAL AZ. COINCIDENTALLY, NBM POPS HAVE NOW INCREASED UP TO  
20-40% ACROSS MUCH OF THE REGION LATE FRIDAY INTO SATURDAY. DUE  
TO THE ARRIVAL OF NEGATIVE HEIGHT ANOMALIES ASSOCIATED WITH THE  
TROUGH, SFC TEMPERATURES ARE EXPECTED TO COOL INTO THE LOWER 80S  
BY FRIDAY AND POTENTIALLY MID TO UPPER 70S ON SATURDAY.  
 
 
   
AVIATION  
UPDATED AT 1135Z.  
 
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT; AND  
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:  
 
NO AVIATION WEATHER CONCERNS WILL EXIST ACROSS THE AIRSPACE FOR  
THE ENTIRE FORECAST PERIOD. WINDS WILL FOLLOW TYPICAL DIURNAL  
TRENDS WITH SPEEDS REMAINING AOB 6 KTS. EXTENDED PERIODS OF CALM  
AND VRB CONDITIONS CAN ALSO BE ANTICIPATED.  
 
 
   
FIRE WEATHER  
 
WARM AND DRY CONDITIONS WITH WELL ABOVE NORMAL TEMPERATURES  
WILL PREVAIL THIS WEEKEND AND THROUGH MUCH OF NEXT WEEK.  
AFTERNOON MINIMUM HUMIDITY WILL BOTTOM OUT BETWEEN 15-20% OVER  
THE NEXT SEVERAL DAYS WITH OVERNIGHT RECOVERIES RANGING FROM  
30-60%. WINDS WILL REMAIN LIGHT, GENERALLY 15 MPH OR LESS WITH  
OCCASIONAL AFTERNOON GUSTS AND WILL TEND TO FOLLOW A TYPICAL  
DIURNAL UPSLOPE/NOCTURNAL DRAINAGE PATTERN.  
 
 
   
PSR WATCHES/WARNINGS/ADVISORIES  
 
AZ...NONE.  
CA...NONE.  
 
 
 
 
SHORT TERM...SALERNO  
LONG TERM...SALERNO  
AVIATION...SALERNO  
FIRE WEATHER...SALERNO  
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