878  
FXUS65 KPSR 222335  
AFDPSR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PHOENIX AZ  
435 PM MST WED JUL 22 2026  
   
UPDATE...UPDATED 00Z AVIATION DISCUSSION
 
 

 
   
KEY MESSAGES
 
 
- TEMPERATURES WILL INCREASE SIGNIFICANTLY THE REMAINDER OF THE WEEK  
WITH EXTREME HEAT WARNINGS IN EFFECT AS READINGS APPROACH NEAR  
RECORD LEVELS.  
 
- HIGH PRESSURE RESPONSIBLE FOR THE EXTREME HEAT WILL ALSO RESTRICT  
THUNDERSTORM DEVELOPMENT WITH CHANCES RETREATING WELL INTO THE  
MOUNTAINS THROUGH THE WEEKEND.  
 
- ABOVE NORMAL TEMPERATURES MAY BEGIN TO RELAX EARLY NEXT WEEK AS  
BETTER THUNDERSTORM COVERAGE RETURNS TO THE REGION.  
 

 
   
SHORT TERM /TODAY THROUGH FRIDAY/
 
 
EARLY AFTERNOON SATELLITE WV IMAGERY SHOWED A WEAK CYCLONIC  
CIRCULATION CENTERED OVER SOUTHERN UTAH, AIDING IN THUNDERSTORM  
DEVELOPMENT AROUND THE FOUR CORNERS REGION. FURTHER TO THE SOUTH  
ACROSS SOUTH-CENTRAL ARIZONA, DRIER CONDITIONS ARE BEGINNING TO  
SETTLE IN WITH PWATS DROPPING TO AROUND 1.5-1.8" ACCORDING TO THE  
LATEST MESOANALYSIS. GIVEN THE DRIER, MORE STABLE ATMOSPHERE,  
THUNDERSTORM ACTIVITY WILL BE LIMITED IN COVERAGE TODAY AND  
PRIMARILY CONFINED TO THE HIGHER TERRAIN/OROGRAPHIC FEATURES EAST OF  
PHOENIX. NBM POPS ARE HIGHEST ACROSS SOUTHERN GILA COUNTY (~20%)  
THIS AFTERNOON, QUICKLY DROPPING BELOW 10% ACROSS THE LOWER  
ELEVATIONS, BEFORE ALL AREAS SEE CHANCES FALL BELOW 10% THURSDAY.  
 
THE LARGER WEATHER HAZARD OVER THE NEXT SEVERAL DAYS WILL BE  
BUILDING HEAT AS STRONG SUBTROPICAL RIDGING RETROGRADES BACK INTO  
THE SW CONUS. ENSEMBLE MEMBERS ARE IN EXCELLENT AGREEMENT DEPICTING  
THE CENTRAL ANTI-CYCLONE BECOMING ESTABLISHED OVER WESTERN NEW  
MEXICO BY FRIDAY WITH H5 HEIGHTS SETTLING NEAR 597-598DM.  
SURPRISINGLY GIVEN THE AGREEMENT AMONG THE ENTIRE ENSEMBLE SUITE,  
NUMERICAL SPREAD IS FAIRLY WIDE LIKELY OWING TO DIFFERENCES IN  
BOUNDARY LAYER MOISTURE CONTENT ACROSS THE CWA. GIVEN THE CURRENT  
LOW LEVEL DEWPOINT STATUS IN SOUTH-CENTRAL ARIZONA AND LACK OF  
STRONG FLOW THROUGHOUT THE TROPOSPHERE, IT'S MORE LIKELY MODEST  
MOISTURE LINGERS AND SOME OF THE MORE EXTREME FORECASTS ABOVE THE  
75TH PERCENTILE WILL NOT COME TO FRUITION. HOWEVER ACROSS THE  
WESTERN CWA WHERE MOISTURE IS NOT AS PLENTIFUL, UPPER END READINGS  
ABOVE 115F WILL BE MORE LIKELY. REGARDLESS, WIDESPREAD MAJOR  
HEATRISK (AND LOCAL EXTREME HEATRISK) WITH AFTERNOON HIGHS 5F-10F  
ABOVE NORMAL WILL BECOME COMMON, AND AN EXTREME HEAT WARNING  
CONTINUES.  
 

 
   
LONG TERM /SATURDAY THROUGH TUESDAY/
 
 
STRONG HIGH PRESSURE WILL CONTINUE TO BE THE DOMINANT SYNOPTIC  
FEATURE THROUGH EARLY NEXT WEEK WITH H5 HEIGHTS 596-598DM SPRAWLING  
ACROSS THE FORECAST AREA. UNSURPRISINGLY GIVEN THIS PATTERN,  
WIDESPREAD MAJOR HEATRISK WILL CONTINUE WITH CLEAR CUT WARNING  
CRITERIA PERSISTING THROUGH THE WEEKEND AS TEMPERATURES HOVER 5F-10F  
ABOVE NORMAL. THE PREPONDERANCE OF ENSEMBLE OUTPUT SUGGESTS THE  
CENTER OF THE SUBTROPICAL ANTI-CYLCONE SLOWLY LIFTING THROUGH THE  
FOUR CORNERS AND INTO COLORADO DURING THE FIRST PART OF NEXT WEEK  
ALLOWING EASTERLY FLOW, SUBTLE SHORTWAVES, AND STRONGER, MOIST  
OUTFLOWS TO RETURN TO ARIZONA. EASTERLY WAVE ENERGY WILL ALSO HELP  
ERODE SOME OF THE HIGHER MIDLEVEL HEIGHTS AND TEMPERATURES WHILE  
ALSO AIDING THE DISPLACEMENT OF THE ANTI-CYCLONE CENTER. THESE  
COMBINED EFFORTS SHOULD ALLOW LOCAL H5 HEIGHTS TO FALL BELOW 594DM  
THOUGH THE TIMING AT WHICH THIS EVOLUTION OCCURS IS SOMEWHAT  
UNCERTAIN. AMONG GEFS MEMBERS, THERE IS FAIRLY CONVINCING EVIDENCE  
OF ENHANCED CONVECTION SUNDAY ALLOWING DEEPER OUTFLOW INTRUSIONS  
WHILE H5 HEIGHTS FALL BELOW 594DM REDUCING OR ELIMINATING THE  
EXTREME HEAT THREAT MONDAY. EPS MEMBERS ARE MORE SUGGESTIVE OF  
BETTER CONVECTIVE POTENTIAL DELAYED UNTIL MONDAY EVENING, BUT  
REGARDLESS TEMPERATURES SHOULD RETURN TO NEAR NORMAL LEVELS BY THE  
MIDDLE OF NEXT WEEK WITH THE DIURNAL THUNDERSTORM RISKS ALSO  
RETURNING TO THE REGION.  
 

 
   
AVIATION
 
UPDATED AT 2330Z.  
 
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:  
NO MAJOR AVIATION WEATHER CONCERNS ARE EXPECTED THROUGHOUT THE  
TAF PERIOD. THE OVERALL WIND PATTERN WILL CONTINUE TO FAVOR LIGHT  
AND DIURNAL TENDENCIES ALONG WITH EXTENDED PERIODS OF VARIABLE  
CONDITIONS. FEW TO OCCASIONALLY SCT MID TO HIGH LEVEL CLOUD DECKS  
WITH BASES AS LOW AS 10 KFT WILL BE COMMON THROUGHOUT THE PERIOD.  
 
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:  
NO MAJOR AVIATION WEATHER CONCERNS UNDER A FEW MID TO HIGH LEVEL  
CLOUD DECKS ARE EXPECTED THROUGHOUT THE TAF PERIOD. THE OVERALL  
WIND PATTERN WILL FAVOR LIGHT AND DIURNAL TENDENCIES ALONG WITH  
EXTENDED PERIODS OF VARIABLE CONDITIONS.  
 

 
   
FIRE WEATHER
 
 
THUNDERSTORM CHANCES WILL DWINDLE THE REMAINDER OF THE WEEK WITH  
ONLY SLIGHT CHANCES REMAINING OVER HIGH TERRAIN AREAS OF FAR EASTERN  
DISTRICTS. INSTEAD, TEMPERATURES WILL WARM SIGNIFICANTLY WITH MUCH  
ABOVE NORMAL READINGS AND EXTREME HEAT WARNINGS. DESPITE THE WARMER,  
DRIER CONDITIONS, HUMIDITY LEVELS WILL NOT FALL SUBSTANTIALLY WITH  
MINIMUM AFTERNOON READINGS 15-30% THE NEXT COUPLE DAYS FALLING  
CLOSER TO A 10-25% RANGE OVER THE WEEKEND. CORRESPONDINGLY,  
OVERNIGHT RECOVERY WILL MOSTLY STAY IN A FAIR TO GOOD RANGE OF 30-  
60%. WINDS SHOULD BE FAIRLY LIGHT THROUGH THE PERIOD WITH ONLY LOCAL  
AFTERNOON GUSTS 20-25 MPH.  
 

 
   
PSR WATCHES/WARNINGS/ADVISORIES
 
 
AZ...EXTREME HEAT WARNING UNTIL 8 PM MST MONDAY FOR AZZ530-532.  
 
EXTREME HEAT WARNING FROM 10 AM THURSDAY TO 8 PM MST MONDAY FOR  
AZZ531-533>555-559.  
 
CA...EXTREME HEAT WARNING UNTIL 8 PM PDT MONDAY FOR CAZ562>570.  
 
EXTREME HEAT WARNING FROM 10 AM THURSDAY TO 8 PM PDT MONDAY FOR  
CAZ560-561.  
 

 
 

 
 
SHORT TERM...SMITH/18  
LONG TERM...18  
AVIATION...LOJERO  
FIRE WEATHER...18  
 
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