787  
FXUS65 KPSR 302007  
AFDPSR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PHOENIX AZ  
107 PM MST WED JUL 30 2025  
   
KEY MESSAGES
 
 
- ABOVE NORMAL TEMPERATURES WITH LOWER DESERT HIGHS BETWEEN  
108-114 DEGREES WILL PREVAIL THROUGH NEXT WEEK, RESULTING IN  
WIDESPREAD MODERATE HEATRISK WITH AREAS OF MAJOR HEATRISK ACROSS  
THE SOUTH-CENTRAL AZ LOWER DESERTS FOR FRIDAY AND SATURDAY WITH  
EXTREME HEAT WARNINGS IN EFFECT.  
 
- LIMITED MONSOON MOISTURE WILL RESULT IN DAILY CHANCES FOR  
THUNDERSTORM ACTIVITY ACROSS THE EASTERN ARIZONA HIGH TERRAIN  
THROUGH FRIDAY, WITH ONLY A VERY SLIGHT CHANCE FOR ISOLATED  
ACTIVITY ACROSS THE SOUTH-CENTRAL AZ LOWER DESERTS LATE THURSDAY  
AFTERNOON AND EVENING.  
 

 
   
SHORT TERM /TODAY THROUGH THURSDAY/
 
 
LATEST WATER VAPOR SATELLITE IMAGERY SHOWS A SUBSTANTIAL AMOUNT  
MID TO UPPER-LEVEL DRY AIR IN PLACE AS A RESULT OF SOUTHWESTERLY  
FLOW ALOFT ENVELOPED ACROSS MUCH OF SOUTHERN CA THROUGH WESTERN  
AND CENTRAL AZ FROM A TROUGH SITUATED ACROSS CENTRAL CA. AS A  
RESULT OF THIS PATTERN, MOISTURE LEVELS CONTINUE TO BE WELL-BELOW  
NORMAL WITH THE LATEST SPC MESOANALYSIS SHOWING PWATS RANGING  
BETWEEN 0.5-0.9" ACROSS THE LOWER DESERTS OF SOUTH-CENTRAL AND  
SOUTHWESTERN AZ THROUGH SOUTHEAST CA TO AS HIGH AS 1.0-1.3"  
ACROSS THE SOUTHEASTERN THIRD OF AZ. GIVEN THE MEAGER MOISTURE IN  
PLACE, THUNDERSTORM ACTIVITY SIMILAR TO THE PAST COUPLE OF DAYS  
WILL BE LIMITED TO THE EASTERN AND SOUTHEASTERN THIRD OF AZ THIS  
AFTERNOON THROUGH EARLY THIS EVENING WHILE THE REST OF THE REGION  
WILL REMAIN DRY WITH MOSTLY CLEAR SKIES. HEADING INTO THURSDAY,  
MOISTURE LEVELS DO IMPROVE SOME AS PWATS INCREASE TO 1.0-1.3"  
ACROSS THE SOUTH-CENTRAL AZ LOWER DESERTS, WHICH COULD ALLOW FOR  
SOME OF THUNDERSTORM ACTIVITY THAT DOES DEVELOP DURING THE  
AFTERNOON ACROSS THE EASTERN THIRD OF AZ TO SPREAD WESTWARD.  
HOWEVER, IT IS STILL LOOKING LIKE ANY ACTIVITY THAT ATTEMPTS TO  
DEVELOP INTO THE LOWER-DESERTS WILL BE ISOLATED AT BEST WITH POPS  
AT AROUND 10%.  
 
THE MAIN STORY WILL CONTINUE TO BE THE HOT TEMPERATURES AS  
TEMPERATURES WILL BE A GOOD 3-5 DEGREES ABOVE NORMAL, RANGING  
BETWEEN 107-111 DEGREES ACROSS THE LOWER DESERTS THROUGH THURSDAY  
AS 500 MB HEIGHT FIELDS WILL RANGE BETWEEN 593-596DM. THIS WILL  
RESULT IN WIDESPREAD MODERATE HEATRISK AND THUS ANYONE SCHEDULING  
OUTDOOR ACTIVITIES AS WELL AS THE MOST VULNERABLE COMMUNITIES  
WILL NEED TO TAKE THE NECESSARY HEAT PRECAUTIONS.  
 

 
   
LONG TERM /FRIDAY THROUGH TUESDAY/
 
 
THE UPPER-LEVEL RIDGE WILL STRENGTHEN ACROSS CENTRAL AND SOUTHERN  
AZ FRIDAY AND SATURDAY AS 500 MB HEIGHT FIELDS INCREASE UP TO  
597-598DM. THIS WILL TRANSLATE TO HOTTER TEMPERATURES AS HIGHS  
WILL RANGE BETWEEN 110-114 DEGREES ACROSS THE LOWER DESERTS WITH  
EARLY MORNING LOWS BETWEEN 85-90 DEGREES ACROSS THE PHOENIX METRO  
AREA. THIS WILL BE ENOUGH TO RESULT IN AREAS OF MAJOR HEATRISK  
MATERIALIZING ACROSS THE SOUTH-CENTRAL AZ LOWER DESERTS AND AS A  
RESULT, EXTREME HEAT WARNINGS HAVE BEEN ISSUED FOR BOTH FRIDAY  
AND SATURDAY.  
 
WE ARE EXPECTING SOME LINGERING MOISTURE ACROSS THE EASTERN 1/3RD  
OF ARIZONA ON FRIDAY, BUT WITH THE HIGH CENTER SETTING UP  
DIRECTLY OVER SOUTHERN ARIZONA ANY CHANCES FOR SHOWERS OR STORMS  
SHOULD BE LIMITED TO HIGHER TERRAIN AREAS. MORE ORGANIZED WESTERLY  
DRY FLOW WILL ALSO SET UP FRIDAY INTO SATURDAY WITH PWATS QUICKLY  
DROPPING TO AROUND 0.75" ON SATURDAY, MOSTLY ENDING ANY RAIN  
CHANCES EVEN OVER THE HIGHER TERRAIN. THIS DRY WESTERLY FLOW IS  
EXPECTED TO AT LEAST PERSIST THROUGH SUNDAY, BUT BY MONDAY MODELS  
BEGIN TO SHIFT THE HIGH CENTER MORE OVER NEW MEXICO. IF THIS SHIFT  
OCCURS, IT MAY ALLOW FOR SOME MOISTURE TO BEGIN SEEPING BACK  
NORTHWARD INTO SOUTHERN ARIZONA AS EARLY AS MONDAY. LIMITED 10%  
POPS HAVE ADDED ACROSS THE PHOENIX METRO FOR MONDAY AND TUESDAY  
WITH CHANCES CLOSER TO 20% OVER THE EASTERN ARIZONA HIGH TERRAIN.  
 
TEMPERATURES ARE LIKELY TO TAKE A SLIGHT DIP OF A COUPLE OF  
DEGREES SUNDAY INTO MONDAY AS THE RIDGE SHIFTS AWAY FROM THE AREA  
AND WEAKENS SLIGHTLY. HOWEVER, WE ARE STILL ANTICIPATING THE  
ABOVE NORMAL TEMPERATURES TO CONTINUE WITH HIGHS BETWEEN 107-111  
DEGREES ACROSS THE LOWER DESERTS. LOOKING OUT TOWARD THE LATTER  
HALF OF NEXT WEEK, GUIDANCE IS STILL POINTING AT A RESTRENGTHENING  
OF THE RIDGE AND THE POTENTIAL RETURN OF EXTREME HEAT.  
 

 
   
AVIATION
 
UPDATED AT 1753Z.  
 
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:  
WINDS HAVE SHIFTED W'RLY EARLY AND WILL PERSIST THROUGH THIS  
EVENING, WITH SOME LIGHT VARIABILITY STILL EXPECTED THROUGH NOON.  
AFTERNOON WIND GUSTS UP TO 15-20 KTS ARE EXPECTED. SKIES SHOULD  
REMAIN CLEAR OVER THE PHOENIX AREA THROUGH THIS AFTERNOON, WITH  
CUMULUS AND ISOLATED STORMS DEVELOPING WELL TO THE EAST. THERE IS  
LOW POTENTIAL FOR AN OUTFLOW TO MOVE INTO THE PHOENIX AREA LATE  
THIS EVENING, BUT IF ONE DOES IT WILL MOSTLY JUST SERVE AS AN  
E'RLY WIND SHIFT. SIMILAR CONDITIONS ARE EXPECTED TOMORROW, BUT  
WITH AFTERNOON CUMULUS DEVELOPING CLOSER TO OR IN THE PHOENIX  
AREA.  
 
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:  
NO MAJOR AVIATION WEATHER CONCERNS UNDER CLEAR SKIES CAN BE  
EXPECTED THROUGHOUT THE TAF PERIOD. WINDS WILL FAVOR SOUTHEASTERLY  
DURING THE DAY AT KIPL, WITH WESTERLY WINDS THIS EVENING, AND S-SW  
AT KBLH. PERIODS OF LIGHT VARIABILITY CAN ALSO BE EXPECTED IN THE  
MORNINGS. A FEW GUSTS TO AROUND 20 KTS WILL BE POSSIBLE AT BOTH  
TERMINALS THIS AFTERNOON AND EVENING.  
 

 
   
FIRE WEATHER
 
 
LIMITED MONSOON MOISTURE WILL PROVIDE FOR DAILY CHANCES FOR  
SHOWERS AND ISOLATED THUNDERSTORMS PRIMARILY OVER THE EASTERN  
ARIZONA HIGH TERRAIN. CHANCES FOR WETTING RAINS WILL REMAIN BELOW  
10% RESULTING IN AT LEAST MINOR RISK OF DRY LIGHTNING. AFTERNOON  
MINRHS THROUGH FRIDAY WILL REMAIN BETWEEN 10-15% ACROSS THE LOWER  
DESERTS TO 15-20% IN HIGHER TERRAIN AREAS. OUTSIDE OF THE  
INFLUENCE OF THUNDERSTORMS, WINDS WILL GENERALLY FOLLOW DIURNAL  
TENDENCIES WITH TYPICAL AFTERNOON UPSLOPE GUSTINESS. TEMPERATURES  
WILL REMAIN ABOVE NORMAL WITH LOWER DESERT HIGHS MOSTLY BETWEEN  
108-112 DEGREES. HIGH PRESSURE WILL AGAIN TAKE OVER ACROSS THE  
REGION BY THE WEEKEND WITH CONDITIONS DRYING OUT FURTHER. THIS  
WILL PUSH HUMIDITIES INTO THE SINGLE DIGITS AND END ANY RAIN  
CHANCES.  
 

 
   
PSR WATCHES/WARNINGS/ADVISORIES
 
 
AZ...EXTREME HEAT WARNING FROM 10 AM FRIDAY TO 8 PM MST SATURDAY FOR  
AZZ534-537>544-546-548>555-559.  
 
CA...NONE.  

 
 

 
 
SHORT TERM...LOJERO  
LONG TERM...LOJERO/KUHLMAN  
AVIATION...BENEDICT/SMITH  
FIRE WEATHER...KUHLMAN  
 
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