103  
FXUS65 KPSR 191932  
AFDPSR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PHOENIX AZ  
1230 PM MST FRI DEC 19 2025  
   
KEY MESSAGES  
 
- DRY AND TRANQUIL WEATHER CONDITIONS WITH WELL ABOVE NORMAL  
TEMPERATURES WILL PREVAIL ACROSS THE REGION THROUGH EARLY NEXT  
WEEK.  
 
- A MORE UNSETTLED WEATHER PATTERN IS LIKELY TO DEVELOP LATER  
NEXT WEEK WITH COOLER TEMPERATURES AND INCREASED PRECIPITATION  
CHANCES  
 
 
   
SHORT TERM /TODAY THROUGH SATURDAY/  
 
UNSEASONABLY WARM WEATHER REMAINS IN PLACE TO FINISH OUT THE  
WORKWEEK AS AFTERNOON READINGS WILL TOP OUT AROUND 10-15 DEGREES  
ABOVE NORMAL. THIS IS THANKS TO A STRONG RIDGE SITUATED OVER THE  
DESERT SOUTHWEST WITH THE CENTER OF THE HIGH POSITIONED TO THE WEST  
OF THE BAJA PENINSULA. THIS PATTERN WILL PERSIST INTO THE WEEKEND  
ALLOWING FOR CONTINUED WELL ABOVE NORMAL TEMPERATURES AS WELL AS  
DRY, TRANQUIL WEATHER CONDITIONS. AFTERNOON TEMPERATURES ON SATURDAY  
ARE EXPECTED TO BE AROUND 2-3 DEGREES COOLER THAN TODAY AS HIGHS  
ACROSS THE LOWER DESERTS ARE FORECAST TO TOP OUT IN THE MID TO UPPER  
70S.  
 
 
   
LONG TERM /SUNDAY THROUGH LATE NEXT WEEK/  
 
UPPER-LEVEL RIDGING WILL CONTINUE TO DOMINATE THE OVERALL WEATHER  
PATTERN ACROSS THE DESERT SOUTHWEST THROUGH THE FIRST HALF OF  
NEXT WEEK, CONTINUING THE DRY AND TRANQUIL CONDITIONS.  
TEMPERATURES WILL CONTINUE TO REMAIN UNSEASONABLY WARM AS  
AFTERNOON HIGHS TOP OUT IN THE UPPER 70S TO AROUND 80 DEGREES  
ACROSS THE LOWER DESERTS. THERE CONTINUES TO BE A HIGH PROBABILITY  
(>70% CHANCE) OF PHOENIX AT LEAST TYING TO EVEN BREAKING DAILY  
RECORD HIGHS BOTH ON SUNDAY AND MONDAY ACCORDING TO THE LATEST  
NBM.  
 
A MORE UNSETTLED WEATHER PATTERN THEN IS LIKELY TO ENSUE HEADING  
TOWARDS THE MIDDLE AND LATTER PORTION OF NEXT WEEK AS THE UPPER-  
LEVEL RIDGE SHIFTS EASTWARD INTO THE SOUTHERN PLAINS, ALLOWING A  
DEEP TROUGH TO BUILD JUST OFF THE WEST COAST. THE DETERMINISTIC  
AND ENSEMBLE MODEL SUITE CONTINUE TO DIVERGE SIGNIFICANTLY ON THE  
OVERALL STRENGTH AND POSITIONING OF THE TROUGH AS IT DEEPENS OFF  
THE WEST COAST, LEADING TO A LOW CONFIDENCE FORECAST HEADING  
TOWARDS THE LATTER PORTION OF NEXT WEEK. ABUNDANT MOISTURE IS  
LIKELY TO SPREAD NORTHEASTWARD FROM THE SUBTROPICAL PACIFIC INTO  
THE REGION FROM LATE TUESDAY INTO WEDNESDAY, WITH BOTH THE EPS AND  
GEFS SHOWING PWATS RISING ABOVE 200% OF NORMAL. GUIDANCE IS  
SHOWING A LEAD SHORTWAVE OUT AHEAD OF THE MAIN TROUGH MOVING  
THROUGH THE GREAT BASIN, WHICH COMBINED WITH THE MOISTURE THAT  
WILL BE IN PLACE, COULD GENERATE SHOWER ACTIVITY ACROSS PORTIONS  
OF THE REGION DURING THE DAY ON WEDNESDAY. PRECIPITATION CHANCES  
AFTER WEDNESDAY WILL THEN BE DEPENDENT ON THE OVERALL STRENGTH AND  
POSITIONING OF THE MAIN TROUGH OFF THE WEST COAST AS IT  
EVENTUALLY MIGRATES INLAND. WITH MORE ABUNDANT CLOUD COVER AND  
POTENTIAL PRECIPITATION AS WELL AS THE DECREASING HEIGHTS ALOFT,  
TEMPERATURES ARE LIKELY TO COOL DOWN LATER NEXT WEEK BY ABOUT 5-10  
DEGREES FROM THE READINGS EARLIER IN THE WEEK BUT STILL REMAIN  
ABOVE NORMAL.  
 
 
   
AVIATION  
UPDATED AT 1720Z.  
 
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT; AND  
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:  
 
NO AVIATION WEATHER CONCERNS UNDER PERIODS OF HIGH CIRRUS DECKS  
CAN BE EXPECTED THROUGHOUT THE TAF PERIOD. WINDS WILL REMAIN LIGHT  
WITH SUBTLE DIURNAL DIRECTIONAL SHIFTS. EXTENDED PERIODS OF  
VARIABLE AND CALM CONDITIONS WILL BE COMMON AS WELL.  
 
 
   
FIRE WEATHER  
 
HIGH PRESSURE ACROSS THE REGION WILL CONTINUE TO PROMOTE DRY AND  
TRANQUIL WEATHER AS WELL AS UNSEASONABLY WARM TEMPERATURES, 10 TO  
15 DEGREES ABOVE NORMAL, INTO EARLY NEXT WEEK. WINDS WILL  
GENERALLY BE LIGHT UNDER 15 MPH. AFTERNOON MINRHS WILL RANGE  
BETWEEN 20-35% WITH GOOD OVERNIGHT RECOVERIES OF 40-70%. A MORE  
UNSETTLED PATTERN IN FORM OF COOLER TEMPERATURES AND INCREASED  
PRECIPITATION CHANCES IS LIKELY LATER NEXT WEEK.  
 
 
   
PSR WATCHES/WARNINGS/ADVISORIES  
 
AZ...NONE.  
CA...NONE.  
 
 
 
 
SHORT TERM...SMITH  
LONG TERM...LOJERO  
AVIATION...LOJERO/18  
FIRE WEATHER...LOJERO  
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