197  
FXUS65 KPSR 230456  
AFDPSR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PHOENIX AZ  
956 PM MST MON JUN 22 2026  
   
UPDATE...UPDATED 06Z AVIATION DISCUSSION  
 
 
   
KEY MESSAGES  
 
- HOTTER TEMPERATURES THIS WEEK WILL RESULT IN WIDESPREAD  
MODERATE HEAT RISK AND LOCALIZED MAJOR HEAT RISK ON WEDNESDAY  
AND THURSDAY.  
 
- AN EXTREME HEAT WATCH HAS BEEN ISSUED FOR PORTIONS OF THE AREA  
ON WEDNESDAY AND THURSDAY WITH FORECAST HIGHS BETWEEN 110 AND  
115 DEGREES ACROSS THE LOWER DESERTS.  
 
- DRY CONDITIONS WILL PREVAIL THROUGH THE NEXT WEEK WITH VERY  
LIMITED CHANCES FOR ISOLATED SHOWERS AND A FEW WEAK STORMS MID  
WEEK FOR PORTIONS OF SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA.  
 
 
   
SHORT TERM /TODAY THROUGH TUESDAY/  
 
A FAIRLY COMPACT, W-E ELONGATED SUBTROPICAL HIGH REMAINS CENTERED  
IN THE VICINITY OF EL PASO EARLY THIS AFTERNOON, WITH ZONAL FLOW  
IN PLACE TO ITS NORTH ACROSS MUCH OF THE WESTERN US. AS TROUGHING  
IN THE NORTHERN STREAM CONTINUES EASTWARD INTO THE NORTH-CENTRAL  
CONUS, ENSEMBLES REMAIN IN EXCELLENT AGREEMENT THAT THE FLATTENED  
SUBTROPICAL HIGH WILL AMPLIFY/EXPAND, INCREASING HEIGHTS ALOFT  
FROM OUR SOUTHEAST. GUIDANCE IS IN GOOD AGREEMENT THAT H5 HEIGHTS  
WILL PEAK LATE TUESDAY INTO WEDNESDAY, WITH ENSEMBLE MEAN VALUES  
BETWEEN 595-598 DAM, AROUND THE 98TH-99TH PERCENTILE OF  
CLIMATOLOGY. THIS WILL RESULT IN INCREASING TEMPERATURES THROUGH  
THE MIDDLE OF THE WORK WEEK, WITH A MAJORITY OF THE TYPICALLY  
HOTTER SPOTS ACROSS THE LOWER DESERTS EXPECTED TO NEAR OR TOP 110F  
TUESDAY AFTERNOON, 3F-6F ABOVE DAILY NORMALS.  
 
AS THE SUBTROPICAL HIGH STRENGTHENS TO OUR SOUTHEAST, SOUTHERLY  
FLOW ALOFT WILL BECOME ESTABLISHED AND IMPORT MODEST MIDLEVEL  
MOISTURE INTO THE REGION. CURRENT MIDLEVEL WATER VAPOR IMAGERY  
DOES INDICATE A SUBTLE PLUME OF MOISTURE OVER THE NORTHERN  
BAJA/GULF OF CALIFORNIA AND OFFSHORE, WITH A COLLOCATED  
DEFORMATION AXIS AND AREA OF UPPER LEVEL DIFFLUENCE SHIFTING  
NORTHWARD. MOISTURE MAY COMBINE WITH THIS TRANSIENT ASCENT  
MECHANISM TO RESULT IN ISOLATED SHOWER ACTIVITY OVER PORTIONS OF  
THE WESTERN CWA LATE TUESDAY, HOWEVER, POPS ARE MOSTLY FOCUSED  
OVER CENTRAL RIVERSIDE COUNTY/JOSHUA TREE NP. THE PRIMARY IMPACT  
FROM THIS INCREASE IN MOISTURE WILL BE THE INTRODUCTION OF  
MIDLEVEL CLOUD COVER AND HIGHER HUMIDITY AT THE SURFACE RESULTING  
IN MUCH WARMER OVERNIGHT LOWS HEADING INTO THE MIDDLE OF THE WEEK.  
 
 
   
LONG TERM /WEDNESDAY THROUGH SUNDAY/  
 
THE INCREASING INFLUENCE FROM THE SUBTROPICAL HIGH PUSHING  
TEMPERATURES EVEN HOTTER WEDNESDAY INTO THURSDAY WILL BE THE MAIN  
FORECAST CONCERN LATER THIS WEEK. THE LATEST NBM FORECAST  
TEMPERATURES HAVE BOUNCED BACK FROM THE SLIGHT DIP WITH  
YESTERDAY'S GUIDANCE WITH THE BULK OF THE LOWER DESERT SHOWING  
HIGHS BETWEEN 111-114 DEGREES FOR BOTH WEDNESDAY AND THURSDAY. THE  
INCREASE IN LOW LEVEL MOISTURE WILL ALSO LEAD TO MUCH WARMER  
OVERNIGHT LOWS WITH READINGS ONLY DIPPING INTO THE LOW TO MID 80S  
FOR MUCH OF THE AREA TO AS WARM AS THE UPPER 80S TO AROUND 90  
DEGREES FOR MUCH OF THE PHOENIX METRO. DUE TO THE BUILDING HEAT,  
WE HAVE ISSUED AN EXTREME HEAT WATCH FOR PORTIONS OF THE AREA,  
INCLUDING PHOENIX, YUMA, AND EL CENTRO FOR WEDNESDAY AND THURSDAY.  
 
AN UPPER LEVEL TROUGH WILL SLIDE SOUTHEASTWARD INTO THE  
NORTHWESTERN U.S. STARTING WEDNESDAY AND EVENTUALLY CLOSER TO OUR  
REGION BY FRIDAY. THIS FEATURE WILL HELP TO LOWER HEIGHTS ACROSS  
OUR REGION STARTING THURSDAY, BUT THERE WILL BE A NOTICEABLE LAG  
TO ANY DECENT COOLING. FORECAST HIGHS FRIDAY ARE STILL BETWEEN  
110-113 DEGREES, BUT OVERNIGHT TEMPERATURES SHOULD COOL OFF MORE  
QUICKLY DUE TO THE EXPECTED DRIER AIR THAT WILL WORK INTO THE  
AREA FROM THE WEST STARTING ON FRIDAY. THE TROUGH TO OUR NORTH  
SHOULD REALLY START TO INFLUENCE OUR REGION BY THE COMING WEEKEND,  
KNOCKING DOWN H5 HEIGHTS MORE INTO A 585-588DM RANGE SATURDAY TO  
AS LOW AS 582-585DM ON SUNDAY INTO NEXT MONDAY. NBM FORECAST HIGHS  
ARE SHOWN TO DIP INTO OR EVEN A FEW DEGREES BELOW NORMAL BY  
SUNDAY. THE MAIN FORECAST CONCERN WILL TURN AWAY FROM EXTREME HEAT  
FRIDAY INTO THE COMING WEEKEND AND MORE TOWARD BREEZY TO LOCALLY  
WINDY CONDITIONS CAUSING CRITICAL FIRE WEATHER CONCERNS.  
 
 
   
AVIATION  
UPDATED AT 0455Z.  
 
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:  
NO AVIATION WEATHER CONCERNS EXPECTED THROUGHOUT THE TAF PERIOD.  
THE OVERALL WIND PATTERN WILL FOLLOW THE TYPICAL DIURNAL  
TENDENCIES WITH SPEEDS AOB 10 KTS ALONG WITH SOME OCCASIONAL  
AFTERNOON/EARLY EVENING GUSTS IN THE MID TO UPPER TEENS. THERE IS  
A BIT OF UNCERTAINTY OF WHETHER OR NOT A FULL EASTERLY SHIFT  
MATERIALIZES OVERNIGHT TONIGHT INTO EARLY TUESDAY MORNING,  
ESPECIALLY AT KPHX, WITH THE POTENTIAL FOR VARIABLE DIRECTIONS TO  
BE MORE PROMINENT. NEVERTHELESS, A FULL WESTERLY SHIFT SHOULD  
MATERIALIZE BY THE MID TO LATE MORNING HOURS. CLEAR SKIES WILL  
PREVAIL INTO TUESDAY MORNING BEFORE SOME MID TO HIGH CLOUDS MOVE  
IN DURING THE AFTERNOON/EVENING HOURS.  
 
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:  
NO MAJOR AVIATION WEATHER CONCERNS CAN BE EXPECTED THROUGHOUT THE  
TAF PERIOD. AT KIPL, WINDS WILL GENERALLY BE OUT OF THE SOUTHEAST  
WHILE AT KBLH, WINDS WILL GENERALLY BE OUT OF THE SOUTH. SOME  
GUSTS BETWEEN 20-25 KTS CAN BE EXPECTED AT KBLH ONCE AGAIN TUESDAY  
AFTERNOON. CLEAR SKIES WILL PREVAIL INTO TUESDAY MORNING BEFORE  
SOME MID TO HIGH CLOUDS MOVE IN DURING THE AFTERNOON/EVENING  
HOURS.  
 
 
   
FIRE WEATHER  
 
LOCALLY ELEVATED FIRE WEATHER CONDITIONS DUE TO VERY LOW HUMIDITY  
AND AFTERNOON UPSLOPE/UPVALLEY BREEZINESS WILL CONTINUE THROUGH  
THE MIDDLE OF THE WEEK. AFTERNOON MINIMUM HUMIDITIES WILL IMPROVE  
SLIGHTLY INTO A 10-15% RANGE STARTING TUESDAY, HOWEVER, THERE WILL  
BE LITTLE TO NO IMPROVEMENT IN OVERNIGHT RECOVERIES AS THEY  
REMAIN MOSTLY POOR BETWEEN 15-35%. TEMPERATURES WILL HEAT UP INTO  
AN ABOVE NORMAL CATEGORY FOR MUCH OF THE WEEK WITH LOWER DESERT  
HIGHS TOPPING 110 DEGREES AT LEAST ON WEDNESDAY AND THURSDAY, AND  
OVERNIGHT LOWS WILL OFFER LITTLE RELIEF AS THEY RISE INTO THE 80S  
FOR MUCH OF THE LOWER DESERTS. WINDS WILL REMAIN GENERALLY TERRAIN  
DRIVEN THROUGH THE MIDDLE OF THE WEEK WITH UPSLOPE/UPVALLEY GUSTS  
BETWEEN 20-25 MPH DURING THE LATTER HALF OF THE AFTERNOON INTO  
THE EARLY EVENING. AREAS OF CRITICAL FIRE WEATHER CONDITIONS LOOK  
LIKELY BY FRIDAY OR SATURDAY AS SOUTHWESTERLY WINDS INCREASE  
ACROSS THE REGION.  
 
 
   
PSR WATCHES/WARNINGS/ADVISORIES  
 
AZ...EXTREME HEAT WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY  
EVENING FOR AZZ530-532-533-537-540-542>544-546-548-550-551.  
 
EXTREME HEAT WARNING FROM 11 AM TUESDAY TO 8 PM MST WEDNESDAY  
FOR AZZ560.  
 
CA...EXTREME HEAT WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY  
EVENING FOR CAZ562-566-567-569.  
 
 
 
 
 
SHORT TERM...WHITTOCK  
LONG TERM...KUHLMAN  
AVIATION...LOJERO  
FIRE WEATHER...WHITTOCK/KUHLMAN  
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