371  
FXUS65 KPSR 060500  
AFDPSR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PHOENIX AZ  
1000 PM MST FRI DEC 5 2025  
   
UPDATE...UPDATED 06Z AVIATION DISCUSSION  
 
 
   
KEY MESSAGES  
 
- DRY AND GENERALLY QUIET CONDITIONS WILL CONTINUE THROUGH AT  
LEAST THE UPCOMING WORK WEEK.  
 
- TEMPERATURES WILL WARM OVER THE WEEKEND INTO THE UPCOMING WORK  
WEEK, LIKELY REACHING 8 TO 10 DEGREES ABOVE DAILY NORMALS.  
 
 
   
SHORT TERM /TODAY THROUGH SATURDAY/  
 
WITH WINDS CALMER THAN THAT OF WEDNESDAY NIGHT AND SKIES REMAINING  
MOSTLY CLEAR, MANY VALLEY LOCATIONS ACROSS THE FORECAST AREA SAW AN  
EVEN CHILLIER THURSDAY NIGHT/FRIDAY MORNING. TEMPERATURES AROUND 6-8  
AM MST THIS MORNING WERE BETWEEN 1-8 DEGREES COOLER THAN THE SAME  
TIME YESTERDAY MORNING (EXCEPT FOR SITES THAT ARE POSITIONED ATOP  
PROMINENT TERRAIN FEATURES, AT AN ELEVATION THAT IS NEAR OR ABOVE  
THE TOP OF THE SURFACE INVERSION.) TEMPERATURES AT OR BELOW  
FREEZING (<=32F) WERE OBSERVED AT SEVERAL AUTOMATED SITES WITHIN  
THE HIGHER ELEVATION, POPULATED VALLEYS OF SOUTHERN GILA COUNTY.  
HOWEVER, TODAY WILL BE THE COOLEST DAY OF AT LEAST THE NEXT 7  
DAYS, WITH FORECAST AFTERNOON HIGHS IN THE MIDDLE TO UPPER 60S  
ACROSS THE LOWER DESERTS, NEAR OR EVEN SLIGHTLY BELOW NORMAL  
VALUES FOR THE DATE. THEN A WARMING TREND COMMENCES THIS WEEKEND.  
 
THE WARMING TREND OVER THE WEEKEND AND INTO THE UPCOMING WORK  
WEEK WILL BE A RESULT OF THE CURRENT UPPER LEVEL PATTERN, WHICH IS  
CHARACTERIZED BY A BROAD RIDGE OVER THE EAST PACIFIC AND LONGWAVE  
TROUGHING DOWNSTREAM, PERSISTING AND GRADUALLY SHIFTING EASTWARD.  
THIS WILL BRING OUR REGION SOLIDLY UNDER THE INFLUENCE OF HIGH  
PRESSURE, WITH POSITIVE MIDLEVEL HEIGHT ANOMALIES BUILDING INTO  
THE DESERT SOUTHWEST FROM THE WEST/NORTHWEST. THE GROWING  
INFLUENCE OF THE RIDGE SHOULD ALLOW FOR SLIGHT WARMING SATURDAY,  
WITH TEMPERATURES GENERALLY 1-3 DEGREES WARMER THAN TODAY.  
 
 
   
LONG TERM /SUNDAY THROUGH THE END OF NEXT WEEK/  
 
BY SUNDAY THE AFOREMENTIONED HIGH PRESSURE SYSTEM IN THE EASTERN  
PACIFIC WILL HAVE MOVED FURTHER SOUTH AND EAST AND WILL STALL JUST  
OFF THE CALIFORNIA COAST. WITH THE HIGH PRESSURE PUSHING FURTHER  
EAST THE LONGWAVE TROUGHING, THAT HAD BEEN KEEPING OUR REGION  
COOLER, WILL ALSO MOVE EASTWARD AND WILL FINALLY EXIT OUR REGION.  
DESPITE THE CENTER OF THE HIGH PRESSURE SYSTEM REMAINING OFF SHORE  
THROUGH THE MIDDLE OF NEXT WEEK, MUCH OF WESTERN CONUS WILL BE UNDER  
THE INFLUENCE OF ITS EASTERN FLANK. H5 HEIGHTS WILL RISE TO AROUND  
580-583 DM ON SUNDAY AND THEN RISE TO 582-585 DM BY THE MIDDLE OF  
NEXT WEEK. THIS WILL RESULT IN A GRADUAL WARMING TREND. HOWEVER,  
THROUGH EARLY NEXT WEEK MULTIPLE SHORTWAVES WILL BE MOVING FROM THE  
PACIFIC NW/SOUTHERN BRITISH COLUMBIA DOWN INTO THE PLAINS THAT WILL  
TEMPORALLY DAMPEN THE RIDGE, BUT, THE RIDGE WILL QUICKLY REBOUND. IF  
ANY OF THESE SHORTWAVES ARE ABLE TO PUSH INTO THE DESERT SOUTHWEST  
AT ALL, IT WOULD BRIEFLY STALL OUR WARMING TREND FOR A DAY.  
NEVERTHELESS, AFTERNOON HIGH TEMPERATURES, REGION WIDE, WILL GO BACK  
ABOVE NORMAL ON SUNDAY AND WARM TO AROUND 8-10 DEGREES ABOVE NORMAL  
BY THE MIDDLE OF NEXT WEEK. AFTERNOON HIGH TEMPERATURES ARE  
FORECASTED TO GO FROM THE LOW 70S (MID TO UPPER 60S) ACROSS THE  
LOWER DESERTS (HIGHER TERRAIN) ON SUNDAY TO THE MID TO UPPER 70S  
(UPPER 60S TO LOW 70S) BY THE MIDDLE OF THE WEEK.  
 
BY THE END OF NEXT WEEK AND HEADING INTO NEXT WEEKEND, THE RIDGE  
WILL FINALLY PUSH ONSHORE WITH THE CENTER OF THE RIDGE EVENTUALLY  
MOVING OVER THE DESERT SOUTHWEST. THE RIDGE WILL BE WEAKENING AS IT  
MOVE ONSHORE, HOWEVER, WITH IT MOVING DIRECTLY OVERHEAD TEMPERATURES  
WILL CONTINUE TO GRADUALLY WARM THROUGH AT LEAST THE END OF NEXT  
WEEK. H5 HEIGHTS WILL RISE INTO THE 583-586 DM RANGE BY THE END OF  
NEXT WEEK. THIS WILL RESULT IN AFTERNOON HIGH TEMPERATURES 10-12  
DEGREES ABOVE NORMAL AND MORNING LOW TEMPERATURES 6-8 DEGREES ABOVE  
NORMAL. FOR THE END OF NEXT WEEK, AFTERNOON HIGH TEMPERATURES ARE  
FORECASTED TO BE IN THE UPPER 70S TO NEAR 80 DEGREES ACROSS THE  
LOWER DESERTS AND IN THE LOW TO MID 70S ACROSS THE HIGHER TERRAIN.  
MORNING LOWS ARE FORECASTED TO BE IN THE 50S ACROSS THE LOWER  
DESERTS AND IN THE 40S ACROSS THE HIGHER TERRAIN. ADDITIONALLY WITH  
THE A RIDGE DOMINATING THE REGION, DRY AND TRANQUIL CONDITIONS WILL  
CONTINUE THROUGH NEXT WEEK AND INTO NEXT WEEKEND.  
 
 
   
AVIATION  
UPDATED AT 0500Z.  
 
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT; AND  
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:  
 
NO AVIATION WEATHER CONCERNS UNDER CLEAR SKIES EXPECTED THROUGHOUT  
THE TAF PERIOD. THE OVERALL WIND PATTERN WILL CONTINUE TO EXHIBIT  
LIGHT DIURNAL TENDENCIES ALONG WITH EXTENDED PERIODS OF VARIABLE  
TO CALM CONDITIONS.  
 
 
   
FIRE WEATHER  
 
DRY CONDITIONS WILL PREVAIL ACROSS THE REGION THROUGH NEXT WEEK.  
TEMPERATURES WILL BE NEAR TO SLIGHTLY BELOW NORMAL TODAY, WARMING  
ABOVE NORMAL DURING THE WEEKEND, AND THEN PEAK 10-12 DEGREES  
ABOVE NORMAL BY THE END OF NEXT WEEK. WINDS WILL BE LIGHT AND TEND  
TO FOLLOW THEIR TYPICAL DIURNAL TENDENCIES. HUMIDITIES OVER THE  
NEXT WEEK WILL STAY ELEVATED WITH MINRHS MOSTLY RANGING BETWEEN  
20-35% MUCH OF THE TIME, WITH GOOD TO VERY GOOD OVERNIGHT  
RECOVERIES.  
 
 
   
PSR WATCHES/WARNINGS/ADVISORIES  
 
AZ...NONE.  
CA...NONE.  
 
 
 
 
SHORT TERM...WHITTOCK  
LONG TERM...BERISLAVICH  
AVIATION...LOJERO  
FIRE WEATHER...WHITTOCK/BERISLAVICH  
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