547
FXUS65 KPSR 021130
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
430 AM MST SUN AUG 2 2026
KEY MESSAGES
- EXTREME HEAT WILL PERSIST THROUGH THE START OF THE WEEK WITH
HIGH TEMPERATURES TOPPING OUT IN THE 110 TO 118 DEGREE RANGE
OVER MUCH OF THE LOWER DESERTS, HOVERING RIGHT AROUND RECORD
LEVELS.
- EXTREME HEAT WARNINGS ARE IN EFFECT REGIONWIDE THROUGH TUESDAY.
- HIGH PRESSURE AND DRIER AIR OVER THE REGION WILL CONFINE
SHOWERS AND THUNDERSTORMS PRIMARILY TO FAR EASTERN AND
SOUTHEASTERN ARIZONA AREAS THROUGH AT LEAST MONDAY.
- SHOWER AND THUNDERSTORM CHANCES INCREASE ACROSS SOUTH-CENTRAL
ARIZONA BY THE SECOND HALF OF THE WEEK.
SHORT TERM /TODAY THROUGH TUESDAY/
NEAR RECORD STRENGTH HIGH PRESSURE REMAINS IN PLACE OVER AZ THIS
MORNING AND THE 00Z SOUNDING FROM FLAGSTAFF ONCE AGAIN MEASURED A
600DAM 500MB HEIGHT. THIS STRONG HIGH HAS LED TO EXTREME
TEMPERATURES ACROSS THE REGION. HEIGHTS AT 500MB ARE EXPECTED TO
GRADUALLY LOWER A FEW DECAMETERS THROUGH MONDAY, DOWN TO
594-595DAM, WHICH IS STILL RIGHT AT THE 90TH PERCENTILE OF
CLIMATOLOGY. SO, THERE WILL AT LEAST BE A SLOW DECLINE IN AMBIENT
TEMPERATURES THROUGH THE FIRST HALF OF THIS WEEK. FOR TODAY
THOUGH, HIGH TEMPERATURES WILL BE NEARLY IDENTICAL TO YESTERDAY,
WITH MOST LOWER DESERTS TOPPING OUT AROUND 112-118F AFTER ONLY
COOLING OFF INTO THE MIDDLE 80S TO LOWER 90S. THESE TEMPERATURES
WILL ONCE AGAIN LEAD TO WIDESPREAD MAJOR TO EXTREME HEATRISK, AND
BOTH HIGH AND LOW TEMPERATURES WILL BE NEAR DAILY RECORDS. HIGHS
FOR MONDAY WILL ONLY DROP 1-3 DEGREES FROM TODAY AND MOST MAJOR
POPULATED AREAS WILL REMAIN UNDER MAJOR TO EXTREME HEATRISK.
ANOTHER 2-4 DEGREES OF COOLING IS EXPECTED HEADING INTO TUESDAY,
BRINGING THE LOWER DESERT HIGHS DOWN TO 107-113 DEGREES. HOWEVER,
CONDITIONS WILL BECOME MUCH MORE HUMID TUESDAY, AS MOST GUIDANCE
SHOW A STRONG PUSH OF BOUNDARY LAYER MOISTURE FROM THE SOUTH
MONDAY NIGHT THROUGH TUESDAY MORNING. SURFACE DEW POINTS ARE
FORECAST TO REACH THE MIDDLE 60S TO LOWER 70S ACROSS THE LOWER
DESERTS. THIS ADDED HUMIDITY WILL MAKE TEMPERATURES VERY
UNCOMFORTABLE AND LEAD TO HEAT INDICES UP TO 111- 117 DEGREES. AN
EXTREME HEAT WARNING REMAINS IN EFFECT THROUGH MONDAY FOR ALL
AREAS, BUT HAS NOW BEEN EXTENDED THROUGH TUESDAY FOR ALL LOWER
DESERT LOCATIONS, LARGELY DUE TO THE HIGH HUMIDITY. THE WARNING
FOR HIGHER TERRAIN AREAS WILL BE ALLOWED TO EXPIRE MONDAY EVENING.
THE ATMOSPHERIC SETUP WILL LIKELY REMAIN UNFAVORABLE FOR STORMS
IN SOUTH-CENTRAL AZ THROUGH AT LEAST THE START OF THE WEEK, DUE TO
THE VERY WARM TEMPERATURES ALOFT AND SUBSIDENCE WITH THE HIGH
PRESSURE OVERHEAD. STORMS THE NEXT FEW AFTERNOONS WILL CONTINUE TO
FAVOR EASTERN AND SOUTHEASTERN AZ, WITH A NORTHEASTERLY STEERING
WIND. STORMS WILL BE STRONG TO SEVERE ACROSS THESE AREAS. STORMS
MOVING OUT OF THE WHITE MTNS THIS AFTERNOON MAY CLIP INTO PORTIONS
OF FAR SOUTHEAST GILA COUNTY, INCLUDING THE SAN CARLOS AREA, AND
WILL BE CAPABLE OF PRODUCING LOCALLY STRONG TO SEVERE WIND GUSTS.
MONDAY LOOKS TO BE A PARTICULARLY ACTIVE DAY FOR SOUTHEAST AZ, WITH
FAVORABLE SHEAR AND INSTABILITY FOR SOME ORGANIZED STORM
CLUSTERS. GIVEN HIGH DCAPE MAGNITUDES (>1500 J/KG), THE STORMS IN
SOUTHEAST AZ MONDAY WILL BE CAPABLE OF SENDING OUTFLOWS,
POTENTIALLY STRONG AND WITH DUST, WESTWARD AND NORTHWARD THROUGH
PINAL COUNTY. THESE OUTFLOWS AND A GULF SURGE MONDAY NIGHT WILL BE
THE DRIVER OF THE INCREASE IN MOISTURE HEADING INTO TUESDAY.
WHILE THIS SOUNDS PROMISING FOR STORM CHANCES ACROSS THE LOWER
DESERTS HEADING INTO TUESDAY, WITH MUCH BETTER INSTABILITY,
SUBSIDENCE, PERSISTENT VERY WARM TEMPERATURES ALOFT, AND FAIRLY
HIGH INHIBITION WILL CONTINUE TO COUNTER/HINDER CONVECTIVE
POTENTIAL. LATEST NBM POPS SHOW SLIGHT CHANCES (15-20%) FOR STORMS
IN SOUTHERN GILA COUNTY TUESDAY AND 10% POPS FOR THE TABLE TOP
AREA OF WESTERN PINAL AND SOUTHERN MARICOPA COUNTIES. ANY STORM
THAT IS ABLE TO DEVELOP OVER LOWER DESERT AREAS WILL BE CAPABLE OF
PRODUCING VERY STRONG TO LOCALLY SEVERE WIND GUSTS.
LONG TERM /WEDNESDAY THROUGH SATURDAY/
AFTER WEAKENING SLIGHTLY TO START THE WEAK, GLOBAL ENSEMBLES
SUPPORT THE SUBTROPICAL HIGH RESTRENGTHENING DURING THE SECOND
HALF OF THE WEEK, BACK UP TO A 600DAM HIGH, BUT ALSO DRIFTING A
LITTLE FURTHER NORTH TOWARD/INTO UT. H5 HEIGHTS OVER THE LOCAL
AREA ARE FORECAST TO CLIMB BACK UP TO A PEAK OF AROUND 596-597DAM
BY FRIDAY. COOLEST TEMPERATURES OVER THE NEXT WEEK ARE FORECAST
FOR WEDNESDAY, BUT TEMPERATURES WILL STILL BE ABOVE NORMAL WITH
LOWER DESERT HIGHS IN THE 106-112 DEGREE RANGE. DESPITE THE
RESTRENGTHENING OF THE HIGH, HIGH TEMPERATURES ARE NOT FORECAST TO
SEE A SIGNIFICANT INCREASE AGAIN, ROUGHLY 1 DEGREE EACH DAY
THROUGH SATURDAY, LIKELY DUE TO THE THE INCREASED MOISTURE.
HOWEVER, THE FORECAST CALLS FOR JUST ENOUGH WARMING TO ONCE AGAIN
INCREASE THE COVERAGE OF MAJOR HEATRISK. MORNING LOW TEMPERATURES
WILL LIKELY REMAIN QUITE WARM - BARRING ANY COOLING FROM STORMS -
MOSTLY IN THE 80S TO RIGHT AROUND 90 DEGREES.
WITH THE SMALL MOVEMENTS OF THE SUBTROPICAL HIGH MIDWEEK AND SHIFT
NORTH LATE WEEK, THERE WILL BE A BETTER FETCH OF EASTERLY WINDS
ACROSS SOUTHERN NEW MEXICO, SOUTHERN ARIZONA, AND NORTHERN MEXICO.
ABOVE NORMAL MOISTURE IS ALSO SHOWN TO STICK AROUND THROUGH THE
END OF THE WEEK AND NEXT WEEKEND, WITH 60S DEW POINTS. THIS
PATTERN WILL AT LEAST SUPPORT DAILY ROBUST THUNDERSTORMS
DEVELOPING OVER THE AZ HIGH TERRAIN, BUT THERE IS STILL
UNCERTAINTY WHETHER STORMS CAN FIRE OFF OR SURVIVE INTO LOWER
DESERT AREAS LIKE PHOENIX AND POINTS FURTHER WEST. STILL, THIS
LOOKS LIKE THE BEST CHANCE OF THE SUMMER SO FAT FOR THUNDERSTORMS
IN PORTIONS OF SOUTHWEST AZ AND SOUTHEAST CA, WHO HAVE BEEN
LACKING FOR RAIN SO FAR THIS SUMMER. LATEST NBM/WPC FORECAST
CONTINUES TO SHOW 10-30% POPS ACROSS MUCH OF SOUTH-CENTRAL
ARIZONA BY THURSDAY AND CONTINUING THROUGH THE END OF THE WEEK. A
PERIOD OF STRONGER MID-LEVEL EASTERLIES AND PERHAPS AND EASTERLY
WAVE/IT WILL CERTAINLY IMPROVE THE ODDS OF STORM CHANCES ACROSS
THE AREA STRONG TO SEVERE WIND GUSTS WILL BE POSSIBLE WITH MOST
STORMS AND AN INCREASE IN MIXING RATIOS UP TO 11-12 G/KG LATE WEEK
WILL SUPPORT VERY HEAVY RAINFALL.
AVIATION
UPDATED AT 1130Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NO MAJOR AVIATION WEATHER CONCERNS UNDER FEW TO OCCASIONALLY SCT
MID TO HIGH-LEVEL CLOUDS CAN BE EXPECTED THROUGHOUT THE TAF
PERIOD. THE OVERALL WIND PATTERN WILL GENERALLY EXHIBIT THE
TYPICAL DIURNAL TENDENCIES WITH OCCASIONAL AFTERNOON/EARLY EVENING
GUSTINESS NEAR 20 KTS.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO MAJOR AVIATION WEATHER CONCERNS UNDER MOSTLY CLEAR SKIES CAN BE
EXPECTED THROUGHOUT THE TAF PERIOD. AT KIPL, SOUTHEAST WINDS WILL
PREVAIL THROUGH THE AFTERNOON BEFORE ANOTHER TEMPORARY SHIFT OUT
OF THE WEST OCCURS DURING THE EVENING HOURS. AT KBLH, WINDS WILL
GENERALLY FLUCTUATE OUT OF THE SOUTH TO SOUTHWEST. OVERALL
SUSTAINED WIND SPEEDS WILL GENERALLY RANGE BETWEEN 8-12 KTS, WITH
SOME OCCASIONAL GUSTS BETWEEN 20-25 KTS AT KBLH DURING THE
AFTERNOON.
FIRE WEATHER
STRONG HIGH PRESSURE AND VERY HOT TEMPERATURES, WITH DRY
CONDITIONS, WILL PERSIST THROUGH THIS WEEKEND. AFTERNOON HIGH
TEMPERATURES WILL BE UP TO 112-118 DEGREES ACROSS LOWER ELEVATIONS
AND MINIMUM RH VALUES WILL BE AROUND 10-15%. TEMPERATURES THEN
DECLINE A FEW DEGREES EACH DAY THROUGH THE FIRST HALF OF THE WEEK
AND MOISTURE LEVELS WILL SLOWLY RISE. MINIMUM RHS WILL STILL BE
AROUND 15-20% MONDAY, BUT WILL INCREASE UP TO 20-30% STARTING
TUESDAY. OVERNIGHT RH RECOVERIES WILL BE FAIR TO GOOD THIS WEEKEND
AT 30-45% AND THEN INCREASE UP TO 45-70%. THE INCREASING MOISTURE
WILL RESULT IN AN INCREASE IN SHOWER AND STORM CHANCES. INITIALLY,
STORM CHANCES THIS WEEKEND THROUGH THE START OF THE WEEK WILL
FOCUS IN FAR EASTERN AND SOUTHEASTERN AZ, WITH POTENTIAL FOR STORM
OUTFLOW WINDS TO PROGRESS INTO SOUTH-CENTRAL AZ. SLIGHT CHANCES
FOR STORMS (15-30%) THEN SPREAD TO SOUTH-CENTRAL AZ BY THE MIDDLE
AND SECOND HALF OF THE WEEK. OUTSIDE OF STORM OUTFLOWS, WINDS
WILL MOSTLY FOLLOW DIURNAL PATTERNS, BUT WEST SOUTHWESTERLY WINDS
WILL BE DOMINANT MUCH OF THE TIME WITH AFTERNOON GUSTS OF 15-25
MPH AT TIMES.
CLIMATE
RECORD HIGH TEMPERATURES:
DATE PHOENIX YUMA EL CENTRO
---- ------- ---- ---------
AUG 2 114 IN 2025 117 IN 1918 117 IN 1969
AUG 3 116 IN 2024 116 IN 1998 117 IN 2021
PSR WATCHES/WARNINGS/ADVISORIES
AZ...EXTREME HEAT WARNING UNTIL 8 PM MST TUESDAY FOR AZZ530>544-546-
548>551-553>555-559.
EXTREME HEAT WARNING UNTIL 8 PM MST MONDAY FOR AZZ545-547-552-
556>558-560>563.
CA...EXTREME HEAT WARNING UNTIL 8 PM PDT TUESDAY FOR CAZ562-563-
565>567-569-570.
EXTREME HEAT WARNING UNTIL 8 PM PDT MONDAY FOR CAZ560-561-564-
568.
SHORT TERM...BENEDICT
LONG TERM...BENEDICT
AVIATION...LOJERO/KUHLMAN
FIRE WEATHER...BENEDICT
CLIMATE...18
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