186  
FXUS65 KPSR 232300  
AFDPSR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PHOENIX AZ  
400 PM MST TUE JUN 23 2026  
   
UPDATE  
00Z AVIATION DISCUSSION  
 
 
   
KEY MESSAGES  
 
- TEMPERATURES BETWEEN 5 AND 10 DEGREES ABOVE NORMAL WILL RESULT  
IN WIDESPREAD MODERATE HEAT RISK WITH LOCALIZED MAJOR HEAT RISK  
THROUGH THURSDAY.  
 
- EXTREME HEAT WARNINGS WILL REMAIN IN EFFECT FOR PORTIONS OF THE  
AREA THROUGH THURSDAY.  
 
- MARGINALLY BETTER MOISTURE LEVELS THROUGH THE MIDDLE OF THE WEEK  
COULD LEAD TO ISOLATED SHOWERS AND VIRGA, WITH BETTER CHANCES  
FOR SHOWERS AND STORMS OVER NORTHERN ARIZONA HIGH TERRAIN.  
 
- DRYING CONDITIONS AND A REGIONAL INCREASE IN WINDS LATE THIS  
WEEK WILL RESULT IN AREAS OF CRITICAL FIRE WEATHER, AND SO FIRE  
WEATHER WATCHES HAVE BEEN ISSUED FOR THE LOWER COLORADO RIVER  
VALLEY AND TONTO NATIONAL FOREST ON FRIDAY AND SATURDAY.  
 
 
   
SHORT TERM /TODAY THROUGH THURSDAY/  
 
LOCAL CONDITIONS THROUGH THURSDAY WILL BE HEAVILY INFLUENCED BY  
THE SUBTROPICAL HIGH CURRENTLY CENTERED NEAR EL PASO ACCORDING TO  
EARLY AFTERNOON WATER VAPOR SATELLITE IMAGERY AND 500 MB RAP  
ANALYSIS. HEIGHTS ALOFT HAVE INCREASED OVER THE FORECAST AREA AS  
THIS HIGH AMPLIFIES/STRENGTHENS, WITH ANALYZED H5 HEIGHTS UP  
AROUND 595-597 DAM, BETWEEN THE 97TH-99TH PERCENTILE OF  
CLIMATOLOGY. MEANWHILE, A PERIOD OF SOUTHERLY FLOW IMPOSED BY THE  
HIGH HAS IMPORTED MARGINAL LEVELS OF MIDLEVEL MOISTURE INTO THE  
AREA. THE 12Z KPSR SOUNDING INDICATED PWATS AROUND 0.95", UP FROM  
0.41" ONLY 24 HOURS AGO. IN YUMA, A SOUNDING TAKEN AT 12Z THIS  
MORNING SHOWED PWAT AROUND 1" AND INCREASED TO AROUND 1.2" BY 18Z  
IN A FOLLOWUP SOUNDING. HOWEVER, THE BULK OF THIS MOISTURE IS IN A  
RELATIVELY SHALLOW LAYER ABOVE 600 MB, AND LOW LEVEL MIXING  
RATIOS BELOW 8 G/KG COUPLED WITH POOR LAPSE RATES/INSTABILITY  
MEASURES PRECLUDE CHANCES FOR DEEP MOIST CONVECTION OVER THE  
FORECAST AREA. A FEW DISTURBANCE MAY ROTATE THROUGH THE AREA ALONG  
THE PERIPHERY OF THE SUBTROPICAL HIGH, INCREASING MIDLEVEL  
MOISTURE AND PROVIDING A TRANSIENT LIFTING MECHANISM FOR ISOLATED  
SHOWERS/VIRGA AND MAYBE EVEN RELEASING SOME ELEVATED INSTABILITY  
AT TIMES, RESULTING IN SOME LOCALIZED RUMBLES OF THUNDER. ONE OF  
THESE DISTURBANCES CAN BE SEEN IN THE MIDLEVEL WATER VAPOR IMAGERY  
MOVING NORTH NORTHWESTWARD OVER THE GULF OF CALIFORNIA AND WILL  
BE OVERHEAD LATE THIS AFTERNOON INTO THE EVENING.  
 
THE LEVELS OF MOISTURE FORECAST IN THE SHORT TERM WITH THIS  
PERIOD OF SOUTHERLY FLOW WILL BE SUPPORTIVE OF NORTHERN ARIZONA  
HIGH TERRAIN THUNDERSTORMS, ESPECIALLY BY WEDNESDAY. FROM  
EXPERIENCE, STORMS WILL NOT FORM OR SURVIVE OVER LOWER ELEVATIONS,  
AWAY FROM PROMINENT TERRAIN FEATURES. THE GREATEST COVERAGE OF  
HIGH TERRAIN SHOWERS AND THUNDERSTORMS WILL LIKELY OCCUR  
WEDNESDAY, COINCIDENT WITH THE BEST AVAILABLE MOISTURE, THEN FLOW  
TURNS SOUTHWESTERLY ALOFT AND INCREASES AS NORTHERN STREAM  
CYCLONIC CURVATURE ENTERS THE NORTHWEST US. THIS WILL BEGIN A  
DRYING TREND FROM WEST TO EAST ACROSS THE AREA THROUGH THE LATTER  
HALF OF THE WEEK.  
 
TEMPERATURES WILL LIKELY PEAK WEDNESDAY, AS LOWER LEVEL THERMAL  
PROFILES WILL HAVE HAD TIME TO RESPOND TO THE INCREASED HEIGHTS  
ALOFT. HOWEVER, SOME AMOUNT OF CLOUD COVER ASSOCIATED WITH THE  
INCREASED MIDLEVEL MOISTURE COMPLICATES THE FORECAST, AND LOWER  
DESERT HIGHS HAVE TRENDED DOWN A DEGREE OR TWO IN SOME PLACES.  
REGARDLESS, MUCH WARMER OVERNIGHT LOWS (80S ACROSS THE TYPICALLY  
WARMER SPOTS) AND AFTERNOON HIGHS NEAR OR IN EXCESS OF 110F TO AS  
MUCH AS 113F-114F WILL RESULT IN AREAS OF MAJOR HEATRISK,  
PARTICULARLY FOR URBAN AREAS LIKE THE PHOENIX METRO. DRYING  
CONDITIONS AND LESS CLOUD COVER THURSDAY SHOULD RESULT IN  
SIMILARLY HOT CONDITIONS TO THAT OF WEDNESDAY, BUT DECREASING  
HEIGHTS ALOFT WILL PRECLUDE THE POSSIBILITY OF TEMPERATURES  
WARMING ANY FURTHER. THUS, EXTREME HEAT WARNINGS WILL BE IN EFFECT  
WEDNESDAY AND THURSDAY FOR PORTIONS OF THE AREA.  
 
 
   
LONG TERM /FRIDAY THROUGH MONDAY/  
 
GLOBAL ENSEMBLE MEMBERS REMAIN IN PRETTY GOOD AGREEMENT ON THE  
OVERALL SYNOPTIC PATTER FOR THE END OF THE WEEK AND INTO THE  
BEGINNING OF NEXT WEEK. THE AFOREMENTIONED UPPER LEVEL TROUGH WILL  
PUSH FURTHER INTO OUR REGION BY THE END OF THE WORKWEEK AND THIS  
WEEKEND. THIS TROUGH WILL LINGER OVER OUR AREA INTO THE BEGINNING OF  
NEXT WEEK. THIS TROUGH FEATURE WILL LEAD TO LOWER HEIGHTS ALOFT AND  
AS A RESULT COOLING TEMPERATURES. TEMPERATURES WILL COOL HEADING  
INTO THE WEEKEND BEFORE LEVELING OUT BY THE END OF THE WEEKEND AND  
BEGINNING OF NEXT WEEK. TEMPERATURES ON FRIDAY AND SATURDAY ARE  
STILL FORECAST TO BE AROUND 2-5 DEGREES ABOVE NORMAL FOR THIS  
TIME OF YEAR. THEN BY THE END OF THE WEEKEND AND BEGINNING OF NEXT  
WEEK TEMPERATURES ARE FORECAST TO FALL SLIGHTLY (2-4 DEGREES)  
BELOW NORMAL. AFTERNOON HIGH TEMPERATURES ARE CURRENTLY FORECAST  
TO BE IN UPPER 90S TO AROUND 105 DEGREES ACROSS THE LOWER DESERTS  
AND IN THE 90S ACROSS THE HIGHER TERRAIN AREAS FOR THE END OF THE  
WEEKEND AND BEGINNING OF NEXT WEEK. MORNING LOW TEMPERATURES WILL  
ALSO BE DECREASING AND ARE FORECAST TO FALL INTO THE 70S TO UPPER  
60S ACROSS THE LOWER DESERTS AND IN THE 60S ACROSS THE HIGHER  
TERRAIN AREAS. AS A RESULT OF THESE DECREASING TEMPERATURES,  
HEATRISK WILL ALSO BE DECREASING ACROSS THE REGION. IN FACT, WITH  
TEMPERATURES FORECAST TO FALL BELOW NORMAL, HEATRISK WILL FALL  
INTO THE MINOR CATEGORY ACROSS THE ENTIRE REGION.  
 
IN ADDITION TO THE COOLER TEMPERATURES THIS TROUGH WILL ALSO BRING  
IN MUCH DRIER CONDITIONS ALONG WITH INCREASING WINDS. THESE DRIER  
CONDITIONS IN COMBINATION WITH INCREASING WINDS WILL RESULT IN  
INCREASING FIRE DANGER. THUS, A FIRE WEATHER WATCH HAS BEEN  
ISSUED FOR THE LOWER COLORADO RIVER VALLEY AND TONTO NATIONAL  
FOREST FOOTHILLS/SOUTHERN GILA COUNTY ON FRIDAY AND SATURDAY.  
 
 
   
AVIATION  
UPDATED AT 2300Z.  
 
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:  
NO MAJOR AVIATION CONCERNS ARE EXPECTED DURING THE TAF PERIOD  
UNDER INCREASING MID-LEVEL CLOUD COVER. WINDS WILL CONTINUE TO  
FAVOR DIURNAL TRENDS WITH OCCASIONAL GUSTS DURING THE AFTERNOON  
AND EVENING HOURS. MUCH LIKE THE PREVIOUS NIGHT, CONFIDENCE  
REGARDING A FULL E'RLY SHIFT AT KPHX IS LOW, WITH A FEW HOURS OF  
VRB CONDITIONS LOOKING MORE LIKELY AT THIS TIME. REGARDLESS OF  
WHAT COMES TO FRUITION, W'RLY FLOW SHOULD BECOME ESTABLISHED A BIT  
EARLIER THAN NORMAL ON WEDNESDAY. SOME VIRGA AROUND THE TERMINAL  
CANNOT BE RULED OUT THIS EVENING, BUT CHANCES OF SHRA AT THE  
TERMINALS IS TOO LOW TO INCLUDE IN THE TAFS.  
 
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:  
THE POTENTIAL FOR SOME VIRGA AND ERRATIC WINDS THIS EVENING AND  
TONIGHT WILL BE THE MAIN AVIATION CONCERN. HOWEVER, CHANCES FOR  
SHRA IN THE VICINITY OF THE TERMINALS IS LESS THAN 10% SO ANY  
MENTION OF RAIN HAS BEEN EXCLUDED FROM THE TAFS. OUTSIDE OF ANY  
ERRATIC WINDS, TYPICAL DIURNAL TRENDS WILL BE FAVORED AT EACH  
SITE, WITH FLOW FLUCTUATING BETWEEN SE AND W AT KIPL, AND  
GENERALLY S'RLY FLOW AT KBLH. WINDOWS OF VRB TO CALM CONDITIONS  
CAN BE EXPECTED DURING THE OVERNIGHT HOURS.  
 
 
   
FIRE WEATHER  
 
LOCALLY ELEVATED FIRE WEATHER CONDITIONS DUE TO LOW HUMIDITY AND  
AFTERNOON BREEZINESS WILL CONTINUE THROUGH THE MIDDLE OF THE  
WEEK. AFTERNOON MINIMUM HUMIDITIES WILL INCREASE TO AROUND 15%  
AREAWIDE WEDNESDAY BEFORE DRYING OUT AGAIN THROUGH THE REST OF THE  
WEEK AND INTO THE WEEKEND. POOR TO FAIR OVERNIGHT RECOVERIES  
BETWEEN 20-40% TONIGHT AND WEDNESDAY NIGHT WILL ALSO DETERIORATE  
THROUGH THE REST OF THE WEEK AND THIS WEEKEND. TEMPERATURES WILL  
REMAIN IN AN ABOVE NORMAL CATEGORY MUCH OF THE WEEK WITH LOWER  
DESERT HIGHS TOPPING 110 DEGREES AT LEAST THROUGH THURSDAY, AND  
OVERNIGHT LOWS WILL OFFER LITTLE RELIEF, MOSTLY IN THE 80S FOR  
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 AND INTO THIS WEEKEND AS SOUTHWESTERLY WINDS INCREASE  
ACROSS THE REGION. A FIRE WEATHER WATCH HAS BEEN ISSUED FOR THE  
LOWER COLORADO RIVER VALLEY AND TONTO NF/SOUTHERN GILA COUNTY  
ZONES FRIDAY-SATURDAY.  
 
 
   
PSR WATCHES/WARNINGS/ADVISORIES  
 
AZ...EXTREME HEAT WARNING FROM 10 AM WEDNESDAY TO 8 PM MST THURSDAY  
FOR AZZ530-532-533-537-540-542>544-546-548-550-551.  
 
FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH SATURDAY EVENING  
FOR AZZ131-133.  
 
EXTREME HEAT WARNING UNTIL 8 PM MST WEDNESDAY FOR AZZ560.  
 
CA...EXTREME HEAT WARNING FROM 10 AM WEDNESDAY TO 8 PM PDT THURSDAY  
FOR CAZ562-566-567-569.  
 
FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH SATURDAY EVENING  
FOR CAZ231.  
 
 
 
 
 
SHORT TERM...WHITTOCK  
LONG TERM...BERISLAVICH/WHITTOCK  
AVIATION...RW  
FIRE WEATHER...WHITTOCK/BERISLAVICH  
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