954
FXUS65 KPSR 051807
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1107 AM MST SUN JUL 5 2026
UPDATE
UPDATED 18Z AVIATION DISCUSSION.
KEY MESSAGES
- VERY HOT TEMPERATURES WILL RETURN OVER THE NEXT FEW DAYS
CREATING MODERATE TO MAJOR HEAT RISK BY TUESDAY AND LASTING
THROUGH AT LEAST THURSDAY.
- AN EXTREME HEAT WATCH HAS BEEN ISSUED FOR TUESDAY THROUGH
THURSDAY ACROSS THE LOWER DESERTS, INCLUDING PHOENIX, YUMA, AND
EL CENTRO. FORECAST HIGHS ARE CURRENTLY 111 TO 116 DEGREES.
- DRY CONDITIONS WILL PREVAIL MUCH OF THE COMING WEEK, ALTHOUGH
ISOLATED STORM CHANCES ARE EXPECTED TO RETURN OVER THE ARIZONA
HIGH TERRAIN BY TUESDAY OR WEDNESDAY.
SHORT TERM /TODAY THROUGH MONDAY/
EXTENSIVE CLOUD COVER ON SATURDAY KEPT MUCH OF THE AREA BELOW
NORMAL, BUT THAT IS EXPECTED TO CHANGE TODAY AS DRY AIR ALOFT WILL
MOVE IN FROM THE SOUTHWEST THROUGHOUT THE DAY. MUCH OF THE AREA
REMAINS QUITE CLOUDY EARLY THIS MORNING AND IT IS LEADING TO VERY
WARM OVERNIGHT TEMPERATURES. AFTER THE WARM START TO TODAY, IT
WILL NOT TAKE MUCH SUNSHINE TO WARM DAYTIME TEMPERATURES TO ABOVE
100 DEGREES WITH HIGHS OF 110 DEGREES LIKELY POSSIBLE FOR SOME
LOCALES. THE WESTERN LOWER DESERTS ARE EXPECTED TO SEE CLEARING
SKIES FIRST THIS MORNING WITH MUCH OF SOUTH-CENTRAL AND EASTERN
ARIZONA LIKELY HANGING ON TO SOME PARTLY CLOUDY SKIES THROUGH AT
LEAST SUNSET.
THE SUBTROPICAL HIGH WILL AGAIN BECOME THE DOMINANT WEATHER
FEATURE STARTING TODAY WITH THE CENTER OF THE HIGH JUST TO OUR
EAST SOUTHEAST. THE CENTER IS STILL FORECAST TO SLOWLY DRIFT
WESTWARD INTO MONDAY, LIKELY SETTING UP OVER SOUTHEAST ARIZONA
WHILE RAISING HEIGHTS EVEN FURTHER ACROSS THE REGION. MONDAY
LOOKS TO BE A CLEAR DAY ACROSS THE WESTERN LOWER DESERTS TO MOSTLY
CLEAR ACROSS THE REST OF ARIZONA. HOWEVER, LOWER LEVEL MOISTURE
WILL CONTINUE TO GRADUALLY IMPROVE THROUGH AT LEAST MONDAY WITH
SURFACE DEW POINTS RISING WELL INTO THE 40S TO EVEN THE LOWER 50S
IN SOUTHWEST ARIZONA. THE RISING HEIGHTS AND MORE SUNSHINE SHOULD
HELP TO PUSH DAYTIME HIGHS ON MONDAY TO OVER 110 DEGREES FOR THE
BULK OF THE LOWER DESERTS WITH READINGS TOPPING OUT BETWEEN
109-113 DEGREES, OR JUST BELOW MAJOR HEATRISK.
LONG TERM /TUESDAY THROUGH SATURDAY/
THE MAIN FORECAST CONCERN FOR THE UPCOMING WEEK IS STILL THE
POTENTIAL FOR EXTREME HEAT ACROSS THE REGION STARTING AS EARLY AS
TUESDAY. GUIDANCE REMAINS VERY CONFIDENT IN THE STRENGTHENING AND
REPOSITIONING OF THE SUBTROPICAL HIGH DIRECTLY OVER ARIZONA FOR
TUESDAY AND WEDNESDAY BEFORE SHIFTING MORE TO THE WEST LATE WEEK.
FORECAST H5 HEIGHTS ARE SHOWN RISING TO ABOVE THE 90TH PERCENTILE
LATER ON TUESDAY AND LASTING THROUGH WEDNESDAY, WHILE BOUNDARY
LAYER MOISTURE SLOWLY IMPROVES. DAYTIME TEMPERATURES ARE EXPECTED
TO REACH TO 110-114 DEGREES ON TUESDAY BEFORE LIKELY PEAKING AT
112-116 DEGREES WEDNESDAY. THE SLIGHTLY HIGHER MOISTURE WILL ALSO
HELP TO KEEP OVERNIGHT TEMPERATURES VERY WARM WITH LOWS ON AVERAGE
IN THE MID 80S TO AS WARM AS THE LOW 90S IN THE URBAN CORE OF
PHOENIX. FORECAST CONFIDENCE CONTINUES TO INCREASE FOR A PERIOD OF
2-4 DAYS OF EXTREME HEAT LATER THIS WEEK WITH THE CORE DAYS BEING
WEDNESDAY AND THURSDAY. FRIDAY MAY ALSO NEED TO BE INCLUDED
DEPENDING ON HOW QUICKLY AND HOW FAR WEST THE HIGH CENTER MOVES
LATER IN THE WEEK. FOR NOW, THE EXTREME HEAT WATCH REMAINS IN
EFFECT FOR TUESDAY-THURSDAY.
THE GRADUAL INCREASE IN MOISTURE EARLY THIS WEEK SHOULD
EVENTUALLY BRING SOME ISOLATED SHOWER AND STORM CHANCES, BUT THE
STRONG SUBSIDENCE UNDER THE RIDGE WILL DEFINITELY HOLD BACK THE
POTENTIAL CONVECTION THROUGH MIDWEEK. LOW END POPS OF 10-15% ARE
MAINLY FORECAST FOR THE HIGHER TERRAIN EAST OF GLOBE THROUGH
THURSDAY WITH LITTLE IF ANY CHANCE OF ANYTHING NEARING THE LOWER
DESERTS. ONCE THE HIGH SHIFTS FAR ENOUGH TO THE WEST BY FRIDAY,
GUIDANCE DOES SHOW SOME ADDITIONAL MOISTURE ADVECTION ACROSS
SOUTHERN AND CENTRAL ARIZONA, BUT HOW MUCH AND EXACTLY WHEN IS
STILL UNKNOWN. A GOOD PORTION OF THE ENSEMBLE MEMBERS THEN SHOW
THE HIGH CENTER DRIFTING BACK TO THE NORTH NORTHEAST NEXT WEEKEND
POTENTIALLY SETTING UP OVER UTAH OR WESTERN COLORADO. IF THIS
OCCURS, IT SHOULD BE QUITE FAVORABLE FOR MONSOON STORM ACTIVITY TO
INCREASE ACROSS MUCH OF OUR AREA, EITHER AT SOME POINT NEXT
WEEKEND OR DURING THE FIRST PART OF THE FOLLOWING WEEK. THE
SUBTROPICAL RIDGE IS ALSO EXPECTED TO STRENGTHEN AGAIN AS IT
SHIFTS SOMEWHERE NEAR THE FOUR CORNERS AREA. THIS WOULD KEEP
HIGHER THAN NORMAL HEIGHTS OVER THE DESERT SOUTHWEST AND LIKELY
LEAD TO A CONTINUATION OF ABOVE NORMAL TEMPERATURES THROUGH AT
LEAST NEXT WEEKEND.
AVIATION
UPDATED AT 1806Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NO SIGNIFICANT AVIATION WEATHER CONCERNS WILL EXIST THROUGH
MONDAY. WINDS WILL MOSTLY FOLLOW TYPICAL DIURNAL TRENDS, WITH A
PERIOD OF LIGHT VARIABILITY DURING DIURNAL WIND SHIFTS. AT KPHX,
THERE WILL BE A LATER THAN USUAL EASTERLY SHIFT TOMORROW MORNING,
AROUND TO 10-12Z, DUE IN PART TO AN INCREASE IN WEST WINDS BETWEEN
03-10Z, UP TO 20-25 KTS, ABOVE THE SURFACE AROUND 500-1000 FT
AGL. CLOUDS HAVE SCATTERED OUT AND WILL REMAIN FEW TO SCT THROUGH
THIS AFTERNOON AND THEN WILL INCREASE TO SCT TO BKN AGAIN TONIGHT
THROUGH EARLY MONDAY MORNING WITH BASES MOSTLY STAYING AOA 15K FT
AGL.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO MAJOR AVIATION WEATHER CONCERNS WILL EXIST THROUGH THE TAF
PERIOD UNDER MOSTLY CLEAR SKIES. AT KIPL, CURRENT WESTERLY WINDS
WILL LIKELY VEER S-SSW THIS AFTERNOON THEN BACK WESTERLY TONIGHT.
SUNDOWNER WIND GUSTS OF 20-25 KT ARE POSSIBLE LATER THIS EVENING
FOR A FEW HOURS BETWEEN 01-06Z. AT KBLH, WINDS WILL FAVOR A S-SW
COMPONENT WITH AFTERNOON SPEEDS TO AROUND 10 KTS AND GUSTS UP TO
20 KTS.
FIRE WEATHER
HOTTER CONDITIONS, BUT A SLIGHT IMPROVEMENT IN MOISTURE IS
EXPECTED FOR THE FIRST HALF OF THIS WEEK. LOWER DESERT HIGHS WILL
WARM TO OVER 110 DEGREES AS EARLY AS MONDAY BEFORE PEAKING AT
AROUND 115 DEGREES MIDWEEK. MINIMUM AFTERNOON HUMIDITIES OF 10-15%
ARE ANTICIPATED EACH DAY WITH OVERNIGHT RECOVERIES OF 25-40%.
WINDS WILL FOLLOW DIURNAL UPSLOPE/DOWNVALLEY PATTERNS WITH MODEST
UPSLOPE AFTERNOON BREEZINESS MOSTLY STAYING BELOW 20 MPH, WHICH
WILL CONTINUE TO RESULT IN PERIODS OF ELEVATED FIRE DANGER.
A GRADUAL INCREASE IN MOISTURE THIS WEEK SHOULD EVENTUALLY LEAD TO
SOME ISOLATED STORM CHANCES ACROSS THE EASTERN ARIZONA HIGH
TERRAIN, BUT ANY CHANCES FOR WETTING RAINS IN SOUTH-CENTRAL AZ IS
MORE LIKELY TO HOLD OFF UNTIL NEXT WEEKEND.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...EXTREME HEAT WATCH FROM TUESDAY MORNING THROUGH THURSDAY EVENING
FOR AZZ530>534-536>551-553>555-559-560-562.
CA...EXTREME HEAT WATCH FROM TUESDAY MORNING THROUGH THURSDAY EVENING
FOR CAZ562-564>570.
SHORT TERM...KUHLMAN
LONG TERM...KUHLMAN
AVIATION...BENEDICT/BERISLAVICH
FIRE WEATHER...KUHLMAN
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