428  
FXUS65 KPSR 011007  
AFDPSR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PHOENIX AZ  
307 AM MST TUE JUL 1 2025  
   
KEY MESSAGES  
 
- EXTREME HEAT CONDITIONS WILL CONTINUE TODAY ACROSS THE LOWER  
DESERTS AS HIGH TEMPERATURES TOP OUT BETWEEN 110-115 DEGREES.  
 
- ISOLATED TO SCATTERED THUNDERSTORMS, WITH STRONG GUSTY WINDS AND  
BLOWING DUST BEING THE MAIN THREATS, WILL IMPACT MUCH OF SOUTH-  
CENTRAL AND EASTERN ARIZONA THIS AFTERNOON AND EVENING AND  
AGAIN ON WEDNESDAY.  
 
- DRIER CONDITIONS WILL END ANY RAIN CHANCES STARTING THURSDAY  
NIGHT WITH NEAR NORMAL TEMPERATURES LASTING INTO SATURDAY,  
BEFORE HEATING BACK UP SUNDAY INTO MONDAY.  
 
 
   
SHORT TERM /TODAY THROUGH WEDNESDAY NIGHT/  
 
THE FIRST TASTE OF THE MONSOON HAS ARRIVED WITH THE RIDGE CENTER  
POSITIONED NEAR THE FOUR CORNERS AREA SINCE SUNDAY NIGHT. THIS HAS  
ALLOWED FOR EASTERLY FLOW INTO EASTERN ARIZONA AND A GRADUAL  
INCREASE IN LOW AND MID LEVEL MOISTURE. MARGINAL MOISTURE WILL  
CONTINUE TO ADVECT INTO EASTERN AND CENTRAL ARIZONA OVER THE NEXT  
24-36 HOURS PUSHING PWATS UP TO 1.2-1.3" OVER SOUTH-CENTRAL  
ARIZONA. HOWEVER, THE MOISTURE TODAY IS EXPECTED TO BE LIMITED  
ENOUGH TO MOSTLY FAVOR HIGHER TERRAIN AREAS. THE LATEST HI-RES  
CAMS SHOW CONVECTION FIRING THIS AFTERNOON ALONG THE MOGOLLON RIM  
INTO THE WHITE MTNS AS WELL AS OVER SOUTHEAST ARIZONA.  
 
THIS ACTIVITY SHOULD PRODUCE AT LEAST ONE ORGANIZED EASTERLY  
PROGRESSING OUTFLOW REACHING PINAL AND EASTERN MARICOPA COUNTY  
SOMETIME BETWEEN 4-7 PM. THIS EXPECTED OUTFLOW HAS A HIGH (~70%)  
PROBABILITY OF PRODUCING 35+ MPH WINDS OVER THE AFOREMENTIONED  
AREAS AND A 30-50% PROBABILITY THROUGH THE REST OF THE PHOENIX  
METRO. THE OUTFLOW WINDS ARE LIKELY TO PRODUCE AREAS OF BLOWING  
DUST ACROSS PINAL CO., WHERE PATCHY DENSE DUST WILL BE POSSIBLE,  
WITH MORE LIMITED BLOWING DUST POTENTIALLY AFFECTING PORTIONS OF  
THE PHOENIX AREA. HI-RES GUIDANCE ALSO SHOWS SOME ISOLATED  
CONVECTION DEVELOPING ALONG THE ADVANCING OUTFLOW, BUT FAIRLY  
LIMITED MOISTURE INTO THE LOWER DESERTS SHOULD KEEP THE SHOWER  
AND/OR THUNDERSTORM ACTIVITY FAIRLY SPARSE. WE ARE CURRENTLY  
CARRYING POPS OF AROUND 30% ACROSS THE HIGHER TERRAIN AND INTO  
CENTRAL PINAL CO. TO 15-20% WITHIN THE PHOENIX METRO. THE LIMITED  
MOISTURE TODAY WILL KEEP RAINFALL AMOUNTS FAIRLY LIGHT WITH ONLY  
VERY LOCALIZED AMOUNTS UP TO 0.5-0.75" POSSIBLE.  
 
TEMPERATURES TODAY ARE FORECAST TO BE A COUPLE DEGREES LOWER THAN  
MONDAY WITH READINGS BETWEEN 110-115 DEGREES, BUT A SLIGHT  
INCREASE IN SURFACE DEW POINTS WILL MAKE IT FEEL JUST AS HOT  
ACROSS THE LOWER DESERTS. THE EXTREME HEAT WARNINGS ARE STILL IN  
EFFECT THROUGH 8 PM TODAY FOR ALL OF THE LOWER DESERTS ACROSS  
SOUTH-CENTRAL AND SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA.  
 
FOR TONIGHT INTO WEDNESDAY MORNING, THE MODEST MONSOON MOISTURE  
IS LIKELY TO HAVE PUSHED AS FAR WEST AS WESTERN MARICOPA CO. WITH  
DRIER AIR STILL GETTING PULLED NORTHEASTWARD INTO SOUTHEAST  
CALIFORNIA AS THE PACIFIC LOW MOVES ONSHORE ACROSS CENTRAL  
CALIFORNIA. BY WEDNESDAY AFTERNOON, WE SHOULD SEE BETTER UPPER  
LEVEL FORCING OVER OUR AREA FROM THE INCOMING PACIFIC LOW AND  
THIS SHOULD COMBINE WITH THE MODEST MONSOON MOISTURE OVER SOUTH-  
CENTRAL AND EASTERN ARIZONA. DESPITE PWATS ONLY BEING AROUND 1.3"  
WEDNESDAY AFTERNOON, THE COLDER AIR ALOFT AND THE FORCING FROM THE  
INCOMING PACIFIC LOW ARE LIKELY TO HELP OVERCOME THE LIMITED  
MOISTURE. THE COLDER AIR ALOFT AND STEEPER LAPSE RATES WILL HELP  
TO BUILD 500-1000 J/KG OF MUCAPE FOR WEDNESDAY AFTERNOON. THE 06Z  
HRRR SHOWS A SCENARIO WHERE CONVECTION NOT ONLY DEVELOPS OVER THE  
HIGHER TERRAIN WEDNESDAY AFTERNOON, BUT ALSO OVER PIMA AND  
SOUTHERN MARICOPA/WESTERN PINAL COUNTIES WITH THE HELP OF THE  
TROUGH. THE HIGHER STORM AREAL COVERAGE IS LIKELY TO PRODUCE  
SEVERAL STORM OUTFLOWS AND LIKELY ADDITIONAL DEVELOPMENT ALONG  
OUTFLOW COLLISIONS, LIKELY AFFECTING PORTIONS OF THE PHOENIX  
METRO. JUST LIKE TODAY, A DRY SUB-CLOUD LAYER SHOULD PROMOTE A  
STRONG GUSTY WIND AND BLOWING DUST THREAT. ONE NEGATIVE WE SEE  
FOR STORM ORGANIZATION AND DURATION IS THE FAIRLY WEAK WINDS ALOFT  
AND OVERALL LOW SHEAR. POTENTIAL RAINFALL AMOUNTS FOR WEDNESDAY  
AFTERNOON AND EVENING WILL BE BETTER THAN TODAY WITH THE BEST  
CELLS POTENTIALLY DROPPING LOCALIZED AMOUNTS OF UP TO AN INCH, BUT  
MOST AREAS ARE NOT LIKELY TO SEE MORE THAN 0.25". NBM POPS OF  
15-20% OVER THE SOUTH-CENTRAL ARIZONA LOWER DESERTS SEEMED TOO LOW  
AND HAVE BEEN ADJUSTED UPWARD TO CLOSER TO 25-30%. THESE HIGHER  
POPS MAY STILL MAY UNDERDONE.  
 
 
   
LONG TERM /THURSDAY THROUGH TUESDAY/  
 
STARTING THURSDAY, GUIDANCE SHOWS THE WEAKENING PACIFIC LOW MOVING  
EASTWARD INTO WESTERN PORTIONS OF THE DESERT SOUTHWEST. THIS WILL  
PUSH WEST SOUTHWESTERLY DRY FLOW OVER OUR AREA THROUGHOUT THE DAY  
THURSDAY. THE TIMING OF THIS DRYING IS STILL A BIT UNCERTAIN, BUT  
IT LIKELY WON'T BE FAST ENOUGH TO STOP SOME ISOLATED TO SCATTERED  
SHOWERS AND THUNDERSTORMS FROM FORMING THURSDAY MORNING AND  
AFTERNOON. POPS THURSDAY ARE ACTUALLY THE HIGHEST OVER THE  
PHOENIX AREA IN THE MORNING AT 20% WITH THE DRIER AIR LIKELY  
ENDING CHANCES IN THE AFTERNOON FOR THE LOWER DESERTS. HIGHER  
TERRAIN AREAS EAST OF PHOENIX SHOULD KEEP RAIN CHANCES THROUGH THE  
AFTERNOON HOURS BEFORE ENDING IN THE EVENING AS THE REMNANTS OF  
THE LOW SHIFTS INTO NORTHEAST ARIZONA. THE PASSAGE OF THE LOW ON  
THURSDAY WILL ALSO KEEP TEMPERATURES FROM REACHING THE NORMAL FOR  
THE DATE WITH HIGHS MOSTLY BETWEEN 100-105 DEGREES.  
 
FOR THE 4TH OF JULY, DRY WESTERLY FLOW WILL END ANY RAIN CHANCES  
AND TEMPERATURES WILL MAYBE GAIN A DEGREE OVER THURSDAY'S HIGHS.  
OVERNIGHT TEMPERATURES WILL ALSO NOTICEABLY IMPROVE BY FRIDAY  
WITH LOWS MOSTLY IN THE 70S FOR THE LOWER DESERTS TO THE LOWER 80S  
WITHIN THE URBAN CORE OF PHOENIX. THE WEATHER PATTERN FOR THE  
COMING WEEKEND WILL INITIALLY KEEP THE BROAD CYCLONIC FLOW IN  
PLACE, BUT WE ARE LIKELY TO SEE THE SUB-TROPICAL RIDGE TO  
GRADUALLY BUILD BACK IN FROM THE EAST WITH A HIGH CENTER FORMING  
SOMEWHERE OVER NEW MEXICO. THIS SHOULD KEEP A DRY WESTERLY FLOW IN  
PLACE THROUGH THE WEEKEND WITH NO REALISTIC RAIN CHANCES. AS THE  
RIDGE GRADUALLY TAKES OVER AGAIN ACROSS OUR REGION, TEMPERATURES  
ARE EXPECTED TO GRADUALLY HEAT UP WITH HIGHS NEARING THE 110  
DEGREE MARK AGAIN AS EARLY AS SUNDAY. THERE IS STILL SOME MODEL  
UNCERTAINTY FOR THE FIRST HALF OF NEXT WEEK, BUT TRENDS ARE  
SHOWING THE RIDGE SHIFTING MORE TOWARD THE FOUR CORNERS AREA BY  
NEXT TUESDAY OR WEDNESDAY ALLOWING MOISTURE AND RAIN CHANCES TO  
AGAIN RETURN TO PORTIONS OF THE AREA.  
 
 
   
AVIATION  
UPDATED AT 0536Z.  
 
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, KDVT:  
AN EARLY SHIFT TO THE EAST IS EXPECTED TONIGHT, AS A WEAK OUTFLOW  
BOUNDARY IS PUSHING THROUGH NOW, WITH ALL TERMINALS SHIFTING EAST  
BY 7-8Z. EASTERLY SUSTAINED WINDS TONIGHT WILL BE AROUND 10-15  
KTS, WITH OCCASIONAL GUSTS TO AROUND 20 KTS. LLWS MAGNITUDES  
TONIGHT ARE EXPECTED TO COME UP SHY OF THE THRESHOLD FOR MENTION  
IN THE TAF (30 KT). GUSTS TO 20 KTS WILL BE MORE COMMON BETWEEN  
15-19Z, AFTER SUNRISE. WINDS SUBSIDE AROUND NOON TOMORROW AND VEER  
TO A SOUTHERLY COMPONENT, WITH SOME 150V220 VARIABILITY THROUGH  
MUCH OF THE AFTERNOON. FEW TO SCT MID LEVEL CLOUDS WILL REMAIN  
ABOVE 12K FT AGL.  
 
VERY HIGH CONFIDENCE AN OUTFLOW BOUNDARY WILL MOVE THROUGH THE  
PHOENIX AREA LATE TOMORROW AFTERNOON AND EVENING, FROM THE E/NE.  
TIMING CURRENTLY LOOKS LIKE AROUND 1-2Z AND THERE ARE 70-80% ODDS  
FOR GUSTS >30 KTS. WINDS WILL BE CAPABLE OF GENERATING BLOWING  
DUST, WITH SURFACE VISIBILITY REDUCTIONS ONLY ANTICIPATED AT KIWA  
AT THIS TIME, WITH SLANTWISE IMPACTS AT OTHER TERMINALS.  
PROBABILITY OF PRECIPITATION (~10%) AND CONFIDENCE IS TOO LOW TO  
INCLUDE ANY SH/TS MENTION IN THE TAFS, BUT SOME ISOLATED  
CONVECTION MAY DEVELOP OVER TERRAIN FEATURES WITHIN 40 MILES OF  
KPHX, LIKE OVER THE SUPERSTITIONS AND THE ESTRELLAS.  
 
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:  
WEST WINDS WILL CONTINUE TO PREVAIL AT KIPL, WHILE KBLH WILL SEE  
PREDOMINANT SOUTH TO SOUTHWEST WINDS. OCCASIONAL WIND GUSTS UP TO  
20-25 KTS ARE ANTICIPATED AT BOTH TERMINALS DURING THE AFTERNOON  
AND EVENING. THERE WILL ALSO BE BRIEF PERIODS OF LIGHT VARIABILITY  
TOMORROW MORNING AT BOTH TERMINALS. SKIES WILL REMAIN MOSTLY CLEAR  
WITH FEW TO SCT DECKS AROUND 15-17K FT AGL TOMORROW MORNING.  
 
 
   
FIRE WEATHER  
 
TODAY WILL AGAIN BE VERY HOT, BUT WITH A SLIGHT UPTICK IN MOISTURE  
LEVELS PUSHING MINRHS THIS AFTERNOON INTO THE TEENS TO UP TO 20%  
FOR MUCH OF THE EASTERN DISTRICTS. THUNDERSTORM ACTIVITY WILL  
ALSO INCREASE TODAY OVER EASTERN ARIZONA HIGHER TERRAIN WITH  
CHANCES UPWARDS OF 40%. GUSTY ERRATIC WINDS ARE LIKELY TO OCCUR  
WITH THE THUNDERSTORM ACTIVITY, WITH OUTFLOW WINDS EXPECTED TO  
MOVE INTO THE SOUTH-CENTRAL ARIZONA LOWER DESERTS BY EARLY  
EVENING. WEDNESDAY SHOULD BRING ANOTHER ACTIVE WEATHER DAY ACROSS  
THE EASTERN DISTRICTS WITH SHOWER AND THUNDERSTORM CHANCES AT  
AROUND 50% OVER THE HIGHER TERRAIN TO AROUND 30% INTO THE LOWER  
DESERTS. HUMIDITIES WILL CONTINUE TO IMPROVE ON WEDNESDAY WITH  
MINRHS AROUND 20% FOR THE LOWER DESERTS TO 30-35% IN GILA CO.  
STORM CHANCES DIMINISH STARTING THURSDAY AND END COMPLETELY BY  
FRIDAY. DRIER AIR WILL FILTER INTO THE REGION BY THE WEEKEND WITH  
MINRHS FALLING TO 10-15% BY SUNDAY. TEMPERATURES WILL RUN NEAR  
NORMAL FROM THURSDAY THROUGH THE WEEKEND.  
 
 
   
PSR WATCHES/WARNINGS/ADVISORIES  
 
AZ...EXTREME HEAT WARNING UNTIL 8 PM MST THIS EVENING FOR AZZ530>540-  
542>544-546-548-550-551-553-554-559.  
 
BLOWING DUST ADVISORY FROM 4 PM THIS AFTERNOON TO 8 PM MST THIS  
EVENING FOR AZZ553-554.  
 
CA...EXTREME HEAT WARNING UNTIL 8 PM PDT THIS EVENING FOR CAZ562-  
565>567-569-570.  
 
 
 
 
 
SHORT TERM/LONG TERM...KUHLMAN  
AVIATION...BENEDICT  
FIRE WEATHER...KUHLMAN  
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