686
FXUS65 KPSR 300939
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
239 AM MST THU JUL 30 2026
KEY MESSAGES
- EXTREME HEAT WILL BUILD OVER THE REGION OVER THE NEXT COUPLE OF
DAYS AND LAST THROUGH AT LEAST THE WEEKEND. EXPECT RECORD TO
NEAR RECORD TEMPERATURES FRIDAY THROUGH SUNDAY.
- EXTREME HEAT WARNINGS ARE IN EFFECT AREAWIDE FROM TODAY THROUGH
SUNDAY.
- DRIER AIR OVER THE REGION WILL CONFINE ANY CHANCES FOR SHOWERS
AND THUNDERSTORMS OVER FAR EASTERN ARIZONA HIGH TERRAIN THROUGH
AT LEAST SUNDAY.
SHORT TERM /TODAY THROUGH FRIDAY/
THE MAIN FORECAST CONCERN OVER THE NEXT SEVERAL DAYS WILL BE THE
BUILDING EXTREME HEAT ACROSS THE REGION AS THE SUBTROPICAL RIDGE
STRENGTHENS AND SHIFTS DIRECTLY OVER ARIZONA STARTING FRIDAY. H5
HEIGHTS ARE FORECAST TO RISE FROM THE CURRENT 592-594DM TO
598-600DM LATER ON FRIDAY AND LAST THROUGH SATURDAY. GUIDANCE
CONTINUES TO INDICATE THE STRENGTH OF THE RIDGE WILL REACH
CLIMATOLOGICAL RECORD LEVELS ACROSS MUCH OF THE SOUTHWESTERN U.S.
FOR FRIDAY INTO SATURDAY.
CURRENT OBJECTIVE ANALYSIS SHOWS THE RIDGE CENTER OVER SOUTHEAST
NEW MEXICO WITH SOUTH SOUTHWESTERLY FLOW ACROSS ARIZONA. IR
IMAGERY ALSO SHOWS EXTENSIVE HIGHER LEVEL CLOUDS ACROSS SONORA
FROM A DECAYING MCS AND SOME OF THIS MOISTURE AND CLOUDS ARE
EXPECTED TO PASS OVER SOUTHEAST AND SOUTH-CENTRAL ARIZONA TODAY.
DRIER AIR ALREADY INFILTRATED THE REGION YESTERDAY, ESPECIALLY IN
THE LOWER LEVELS WHERE MIXING RATIOS HAVE DROPPED TO AROUND 9-10
G/KG IN THE PHOENIX AREA TO AS LOW AS 4-5 G/KG IN SOUTHEAST
CALIFORNIA. THIS DRIER AIR IS HELPING TO COOL OFF NIGHTTIME
TEMPERATURES ACROSS THE WESTERN DESERTS WHERE LOWS THIS MORNING
MAY REACH INTO THE LOWER 80S, BUT HIGHER BOUNDARY LAYER MOISTURE
IN THE PHOENIX AREA WILL KEEP LOWS IN THE UPPER 80S TO THE LOWER
90S.
HIGH TEMPERATURES TODAY WILL EASY TOP 110 DEGREES ACROSS THE
WESTERN DESERTS AND POTENTIALLY REACHING 115 DEGREES IN SOME
SPOTS. THE SCATTERED HIGH CLOUDS OVER CENTRAL AND EASTERN ARIZONA
MAY HELP TO KEEP TEMPERATURES RIGHT AROUND 110 DEGREES IN THE
PHOENIX AREA, BUT THE LATEST NBM FORECAST HIGHS SHOW 110-113
DEGREES AS STRONG MIXING IS LIKELY TO QUICKLY LOWER SURFACE
MOISTURE. JUST LIKE THE LAST COUPLE OF DAYS, LITTLE IF ANY
CONVECTIVE ACTIVITY IS FORECAST FOR TODAY WITH THE ONLY 10% OR
GREATER POPS IN THE WHITE MTNS AND THE RIM. ONCE THE RIDGE CENTER
MOVES OVERHEAD ON FRIDAY, TEMPERATURES WILL CLIMB ANOTHER 2-3
DEGREES UNDER GENERALLY SUNNY SKIES AS HIGHS SHOULD REACH 115
DEGREES FOR THE HOTTEST LOWER DESERT LOCALES. WOULD NOT SURPRISING
TO EVEN HAVE SOME SPOTS HIT 117-118 DEGREES, BUT IT SEEMS MORE
LIKELY THE HOTTEST DAY WILL BE SATURDAY. EXTREME HEAT WARNINGS GO
IN EFFECT LATER THIS MORNING ACROSS THE ENTIRE CWA AND LAST
THROUGH THE UPCOMING WEEKEND.
LONG TERM /SATURDAY THROUGH WEDNESDAY/
MODEL ENSEMBLES HAVE CHANGED LITTLE FROM YESTERDAY'S RUNS SHOWING
THE PEAK OF THE RIDGE AND TEMPERATURES OCCURRING ON SATURDAY
BEFORE THE RIDGE WEAKENS SUNDAY INTO MONDAY. NBM FOREAST HIGHS
HAVE COME DOWN A DEGREE OR SO FROM YESTERDAY, BUT IT IS HARD TO
FIND A GOOD REASON WHY. FORECAST CONFIDENCE REMAINS HIGH THAT
SOME DAILY HEAT RECORDS ARE LIKELY TO BE BROKEN THIS WEEKEND WITH
SOUTHEAST CA LOWER DESERTS REACHING 115-120 DEGREES TO 113-117
DEGREES ACROSS THE ARIZONA LOWER DESERTS. TO GIVE SOME
PROSPECTIVE, PHOENIX HAS ONLY REACHED 116 DEGREES OR HIGHER 18
TIMES AFTER JULY 30TH, HALF OF WHICH OCCURRED SINCE 2023 AND ONLY
REACHED 117 DEGREES OR HIGHER 6 TIMES. THE PROBABILITY OF KPHX
HITTING AT LEAST 116 DEGREES FRIDAY-SUNDAY IS 20%, 67%, AND 35%
RESPECTIVELY. FOR SATURDAY, THE NBM ALSO SHOWS A 20-25%
PROBABILITY OF TYING THE ALL-TIME HOTTEST TEMPERATURE IN AUGUST OF
118 DEGREES WHICH OCCURRED AUGUST 7, 2025. WE WILL HAVE SOME
RELIEF FROM THE EXTREME HEAT AT NIGHT, MORE SO ACROSS THE WESTERN
DESERTS WHERE LOWS SHOULD STILL DIP INTO THE MID TO UPPER 80S. THE
BULK OF THE PHOENIX METRO SHOULD HAVE LOWS ONLY IN A 90-95 DEGREE
RANGE FRIDAY-SUNDAY.
ANY POTENTIAL RAIN CHANCES OVER THE WEEKEND ARE TRENDING EVEN
LOWER WITH GUIDANCE MOSTLY SHOWING ANY DECENT MOISTURE ADVECTION
HOLDING OFF UNTIL LATE SUNDAY INTO MONDAY. SOME MEMBERS STILL
SHOW SOME IMPROVED CHANCES OVER THE EASTERN ARIZONA HIGH TERRAIN
CONVECTION AS EARLY AS SUNDAY WITH POTENTIAL FOR OUTFLOWS INTO
THE PHOENIX AREA SUNDAY EVENING, BUT IT SEEMS MORE LIKELY THAT
WILL NOT OCCUR UNTIL MONDAY AT THE EARLIEST. GUIDANCE DOES AGREE
ON THE RIDGE NOTICEABLY WEAKENING BY MONDAY WITH H5 HEIGHTS
DROPPING TO 594-596DM, BUT THE RESIDUAL HEAT OVER THE REGION MAY
STILL KEEP EXTREME HEAT CONDITIONS THROUGH MONDAY. THE RIDGE
CENTER SHOULD ALSO BEGIN TO DRIFT BACK TO THE NORTHEAST, CLOSER TO
THE FOUR CORNERS AREA BY AROUND NEXT TUESDAY. IF AND WHEN THIS
HAPPENS, IT SHOULD OPEN UP PORTIONS OF THE REGION FOR BETTER
MOISTURE ADVECTION OUT OF THE SOUTHEAST. MONSOON STORM CHANCES ARE
EXPECTED TO GRADUALLY IMPROVE GOING INTO THE MIDDLE OF NEXT WEEK,
WHILE NBM FORECAST HIGHS DROP BACK TO WITHIN A FEW DEGREES OF
NORMALS.
AVIATION
UPDATED AT 0500Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NO SIGNIFICANT WEATHER CONCERNS WILL EXIST THROUGH THURSDAY NIGHT
UNDER OCCASIONAL MID/HIGH CLOUD DECKS. WINDS SHOULD FOLLOW SIMILAR
TRENDS TO THE PAST 24 HOURS WITH UNCERTAINTY REGRADING WHETHER
DIRECTIONS COMPLETE AN EASTERLY SWITCH OVERNIGHT. KPHX MAY NEVER
FULLY COMPLETE THE SWITCH WITH A VARIABLE COMPONENT BRIEFLY
MATERIALIZING BEFORE QUICKLY REVERTING TO WEST BY LATE MORNING. ANY
AFTERNOON GUSTINESS WILL BE LIMITED IN TIME AND SPACE WHILE TS
REMAIN WELL REMOVED FROM THE TERMINALS.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO WEATHER CONCERNS WILL EXIST THROUGH THURSDAY NIGHT UNDER CLEAR
SKIES. TRENDS IN WINDS SHOULD BE VERY SIMILAR TO THE PAST 24 HOURS
FEATURING A PREFERENCE TOWARDS A SOUTHERLY DIRECTION AND ONLY MODEST
AFTERNOON/EARLY EVENING GUSTS AROUND 15KT.
FIRE WEATHER
STRONG HIGH PRESSURE WILL GRADUALLY BUILD OVER THE REGION THROUGH
THE REST OF THE WEEK WHILE INCREASINGLY DRY AIR CONFINES ANY RAIN
CHANCES TO OVER FAR EASTERN ARIZONA. EXPECT HUMIDITIES TO
CONTINUE TO LOWER OVER THE NEXT COUPLE OF DAYS WITH MINRHS
SETTLING AT 10-15% BY FRIDAY, WHILE FALLING OVERNIGHT RHS OFFER
ONLY LITTLE TO MODEST RELIEF. RECORD TO NEAR RECORD TEMPERATURES
ARE ALSO FORECAST FOR FRIDAY AND THROUGH THE UPCOMING WEEKEND.
WINDS WILL MOSTLY FOLLOW DIURNAL PATTERNS, BUT WEST SOUTHWESTERLY
WINDS WILL BE DOMINANT MUCH OF THE TIME WITH AFTERNOON GUSTS OF
15-20 MPH AT TIMES.
CLIMATE
RECORD HIGH TEMPERATURES:
DATE PHOENIX YUMA EL CENTRO
---- ------- ---- ---------
JUL 31 116 IN 2020 119 IN 1957 119 IN 2020
AUG 1 116 IN 1972 117 IN 1993 118 IN 1993
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 SUNDAY FOR AZZ530-532-537-
540-542>544-546-548-550-551.
EXTREME HEAT WARNING FROM 10 AM THIS MORNING TO 8 PM MST SUNDAY
FOR AZZ531-533>536-538-539-541-545-547-549-552>563.
CA...EXTREME HEAT WARNING UNTIL 8 PM PDT SUNDAY FOR CAZ567-569-570.
EXTREME HEAT WARNING FROM 10 AM THIS MORNING TO 8 PM PDT SUNDAY
FOR CAZ560>566-568.
SHORT TERM...KUHLMAN
LONG TERM...KUHLMAN
AVIATION...18
FIRE WEATHER...KUHLMAN
CLIMATE...18
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page