296  
FXUS65 KPSR 121705  
AFDPSR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PHOENIX AZ  
1005 AM MST TUE MAY 12 2026  
   
UPDATE  
 
UPDATED AVIATION  
 
 
   
KEY MESSAGES  
 
- AN EXTREME HEAT WARNING REMAINS IN EFFECT FOR THE PHOENIX METRO  
AREA THROUGH EARLY THIS EVENING.  
 
- BREEZY CONDITIONS WILL DEVELOP ALONG THE LOWER COLORADO RIVER  
VALLEY TODAY AND WEDNESDAY, THEN OVER ARIZONA HIGH TERRAIN ON  
WEDNESDAY.  
 
- A NOTICEABLE COOLING TREND WILL BEGIN WEDNESDAY AND CONTINUE  
THROUGH THE WEEKEND, ALBEIT WITH TEMPERATURE REMAINING SLIGHTLY  
ABOVE NORMAL.  
 
 
   
SHORT TERM /TODAY THROUGH WEDNESDAY/  
 
A STRONG UPPER LEVEL RIDGE WITH NEAR CLIMATOLOGICAL RECORD H5  
HEIGHTS IS POSITIONED ACROSS THE DESERT SOUTHWEST. ADDITIONALLY, A  
WEAK SHORTWAVE TROUGH IS ALSO LOCATED OVER CENTRAL BAJA.  
SOUTHEASTERLY FLOW IN BETWEEN THE TWO SYSTEMS DID RESULT IN SOME  
SCATTERED CONVECTION ACROSS NORTHERN MEXICO YESTERDAY ALONG WITH  
SOME REMNANT MOISTURE FROM THE CONVECTION MAKING ITS WAY  
NORTHWESTWARD INTO SOUTHERN ARIZONA. THIS MOISTURE MAY RESULT IN  
SOME MORNING MID LEVEL CLOUDS, BUT OVERALL TODAY WILL AGAIN BE SUNNY  
TO MOSTLY SUNNY FOR MOST LOCATIONS.  
 
AS THE WEAK SHORTWAVE CONTINUES TO MOVE NORTHWARD INTO SOUTHERN  
CALIFORNIA LATER TODAY, HEIGHT FALLS ACROSS THE WESTERN DESERTS WILL  
BRING SOME SLIGHT RELIEF FROM YESTERDAY'S NEAR 110 DEGREE HIGHS AS  
READINGS MOSTLY TOP OUT BETWEEN 102-106 DEGREES. THE RIDGE WILL  
REMAIN MORE DOMINANT ACROSS ARIZONA RESULTING IN HIGHS OF 105-107  
DEGREES IN THE PHOENIX AREA WHERE AN EXTREME HEAT WARNING REMAINS IN  
EFFECT. THE SOUTHEASTERLY FLOW CONTINUING ACROSS THE AREA THROUGH  
THE REST OF TODAY MAY ALLOW FOR SOME WIDELY ISOLATED CONVECTIVE  
SHOWERS ACROSS SOUTHEAST ARIZONA AND LIKELY SOME CLOUDS INTO THE  
SOUTH-CENTRAL ARIZONA LOWER DESERTS BY THIS EVENING. SOUTHERLY  
BREEZY TO LOCALLY WINDY CONDITIONS WILL ALSO AFFECT PORTIONS OF  
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA THIS AFTERNOON WITH GUSTS  
AS HIGH AS 25-30 MPH IN SOME LOCATIONS.  
 
BY WEDNESDAY MORNING THE WEAK SHORTWAVE IS FORECAST TO HAVE MOVED  
INTO CENTRAL CALIFORNIA AND WESTERN NEVADA AS ANOTHER STRONGER  
PACIFIC WAVE MOVES EASTWARD ACROSS THE PACIFIC NORTHWEST. BOTH  
SYSTEMS WILL COMBINE INTO A LARGER TROUGH WITH A TRAILING TROUGH  
AXIS EVENTUALLY MAKING ITS WAY INTO OUR REGION BY THURSDAY. AT THE  
SAME TIME, IT WILL COMPLETELY DISPLACE THE RIDGE TO THE EAST OF OUR  
REGION ALLOWING FOR MODEST HEIGHT FALLS AND COOLING TEMPERATURES.  
FORECAST HIGHS FOR WEDNESDAY DROP INTO THE UPPER 90S TO JUST OVER  
100 DEGREES ACROSS THE LOWER DESERTS.  
 
 
   
LONG TERM /THURSDAY THROUGH MONDAY/  
 
THE WEATHER PATTERN LATER THIS WEEK IS EXPECTED SHIFT TO A MORE  
ZONAL WESTERLY DRY FLOW PATTERN, BUT WITH SOME INFLUENCE FROM  
PASSING TROUGHS TO OUR NORTH. THE DRYING FLOW WILL RESULT IN CLEAR  
TO MOSTLY CLEAR SKIES FOR THURSDAY-SATURDAY WITH TEMPERATURES  
REMAINING QUITE STABLE AVERAGING 5-7 DEGREES ABOVE NORMAL. ENSEMBLES  
ARE CURRENTLY FAVORING A LARGER PACIFIC TROUGH MOVING THROUGH THE  
PACIFIC NORTHWEST THIS WEEKEND BRINGING LOWER HEIGHTS AS FAR SOUTH  
AS THE SOUTHWESTERN U.S. NBM/WPC TEMPERATURE GUIDANCE SUGGESTS  
DAYTIME HIGHS FALLING BACK MORE INTO THE UPPER 90S BY AROUND SUNDAY.  
 
 
   
AVIATION  
UPDATED AT 1705Z.  
 
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:  
WINDS WILL BE THE PRIMARY WEATHER ISSUE THROUGH WEDNESDAY AFTERNOON  
UNDER PERIODS OF MID/HIGH CLOUD DECKS. CONFIDENCE IS GOOD THAT A  
WESTERLY COMPONENT WILL DEVELOP BY EARLY AFTERNOON, THEN OBTAIN  
ENHANCED GUSTINESS EARLY/MID EVENING. THERE IS SOME UNCERTAINTY IN  
THE MAGNITUDE OF WIND GUSTS, AND VIRGA MAY CREATE SOME ERRATIC  
DIRECTIONS AND SPEEDS FOR A FEW HOURS. OTHERWISE, THE SWITCH TO THE  
NOCTURNAL EASTERLY COMPONENT SHOULD BE DELAYED AGAIN TONIGHT. A  
PERIOD OF 8-12KT SOUTHERLY CROSS RUNWAY WINDS ARE LIKELY WEDNESDAY  
LATE MORNING/EARLY AFTERNOON.  
 
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:  
PERIODS OF GUSTY WINDS WILL BE THE MAIN WEATHER ISSUE THROUGH  
WEDNESDAY AFTERNOON UNDER OCCASIONAL MID/HIGH CLOUD DECKS. A S/SE  
COMPONENT WILL BE FAVORED ACROSS THE AREA THROUGH THE AFTERNOON WITH  
DIRECTIONS AT KIPL LIKELY ABRUPTLY SHIFTING TO SW EARLY EVENING.  
CONFIDENCE IS EXCELLENT THAT GUSTS 20-30KT WILL BECOME COMMON  
THROUGH THE AFTERNOON AND EARLY EVENING BEFORE DECOUPLING AND  
WEAKENING OVERNIGHT.  
 
 
   
FIRE WEATHER  
 
HOT, DRY, AND LOCALLY BREEZY TO WINDY CONDITIONS WILL RESULT IN  
ELEVATED FIRE WEATHER POTENTIAL THIS AFTERNOON ACROSS THE LOWER CO  
RIVER VALLEY. WIND GUSTS OF 20-30 MPH ALONG WITH RHS 7-10% ARE  
EXPECTED ACROSS THE LOWER CO RIVER VALLEY. ELSEWHERE TODAY, WINDS  
WILL BE LIGHTER BUT WITH AFTERNOON GUSTS OF 15-20 MPH POSSIBLE.  
WEDNESDAY WILL BRING ANOTHER ROUND OF BREEZY WINDS OVER SOUTHEAST  
CALIFORNIA AND THE ARIZONA HIGH TERRAIN WITH ELEVATED FIRE WEATHER  
CONDITIONS AGAIN A POSSIBILITY. TEMPERATURES TODAY WILL BE 10-15  
DEGREES ABOVE NORMAL DROPPING TO 5-8 DEGREES ABOVE NORMAL STARTING  
WEDNESDAY. WINDS WILL DIMINISH STARTING THURSDAY, BUT VERY DRY  
CONDITIONS WILL CONTINUE TO PREVAIL.  
 
 
   
PSR WATCHES/WARNINGS/ADVISORIES  
 
AZ...EXTREME HEAT WARNING UNTIL 8 PM MST THIS EVENING FOR AZZ537-540-  
542>544-546-548-550-551.  
 
CA...NONE.  
 
 
 
 
SHORT TERM...KUHLMAN  
LONG TERM...KUHLMAN  
AVIATION...18  
FIRE WEATHER...KUHLMAN  
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