642
FXUS65 KPSR 052322
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
422 PM MST SUN JUL 5 2026
UPDATE
00Z 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 WARNING 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/
IT LOOKS A BIT MESSY ON EARLY AFTERNOON 500MB RAP ANALYSIS, BUT IT
APPEARS THAT THE CENTER OF THE SUB-TROPICAL HIGH HAS SHIFTED
WESTWARD TOWARD ARIZONA AFTER SPENDING SOME TIME OVER TEXAS AND
NEW MEXICO DURING THE START OF THE WEEKEND. AS THIS SHIFT OCCURS,
DRIER AIR HAS BEEN FUNNELING IN OFF THE EASTERN PACIFIC TOWARD THE
DESERT SOUTHWEST, ALLOWING FOR CLEARER SKIES AFTER A VERY CLOUDY
SATURDAY AND FIRST PART OF SUNDAY. THE GREATER INSOLATION THIS
AFTERNOON COMPARED TO YESTERDAY WILL ALLOW FOR A NOTICEABLE WARM
UP FOR PARTS OF THE REGION AFTER SOME AREAS (MAINLY IN SOUTH-
CENTRAL ARIZONA) FAILED TO REACH THE TRIPLE DIGITS. IN FACT, HIGHS
FOR THE PHOENIX METRO MIGHT BE A GOOD 5-10 DEGREE WARMER THAN THE
4TH OF JULY, WHICH TRANSLATES TO READINGS AROUND 105-110 DEGREES.
A SIMILAR TEMP RANGE CAN BE EXPECTED ELSEWHERE ACROSS THE LOWER
DESERTS, BUT THE DAY-TO-DAY DIFFERENCE WILL NOT BE AS STARK,
RUNNING MAYBE 2-4 DEGREES HOTTER.
THE HIGH WILL MORE OR LESS SIT OVER THE DESERT SOUTHWEST AS WE
TRANSITION INTO THE START OF THE UPCOMING WEEK, WHICH WILL ALLOW
FOR FURTHER WARMING REGIONWIDE. AFTERNOON HIGHS 110F AND ABOVE
WILL BE COMMON ACROSS LOWER ELEVATION LOCATIONS, PUSHING US TO
JUST BELOW MAJOR HEATRISK LEVELS. OVERNIGHT LOWS WILL BE THE MAIN
REASON WHY MOST AREAS AVOID REACHING THIS HEATRISK THRESHOLD,
THEREFORE PREVENTING ANY EXTREME HEAT PRODUCTS FROM BEING ISSUED
FOR MONDAY. HOWEVER, FURTHER STRENGTHENING OF THE HIGH AS WE
PROGRESS THROUGH THE FRONT HALF OF THE WEEK MEANS THAT WE WILL NOT
ESCAPE EXTREME HEAT COMPLETELY, AND THAT WILL BE DISCUSSED MORE
BELOW.
LONG TERM /TUESDAY THROUGH SATURDAY/
GUIDANCE REMAINS VERY CONFIDENT IN THE FURTHER AMPLIFICATION 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. IN RESPONSE TO THE FORECAST CERTAINTY,
THE EXTREME HEAT WATCH HAS BEEN UPGRADED TO A WARNING, RUNNING
BETWEEN TUESDAY 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.
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 2330Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NO SIGNIFICANT AVIATION WEATHER CONCERNS WILL EXIST THROUGH
THE FORECAST PERIOD. WINDS WILL MOSTLY FOLLOW TYPICAL DIURNAL
TRENDS, ASIDE FROM EXTENDED PERIODS OF LIGHT AND VRB PRIOR TO THE
ONSET OF DIURNAL WIND SHIFTS. AT KPHX, THERE WILL BE A LATER THAN
USUAL EASTERLY SHIFT ON MONDAY 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 THIS EVENING INTO EARLY MONDAY
MORNING WITH BASES MOSTLY STAYING AOA 15 KFT AGL.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO AVIATION WEATHER CONCERNS WILL EXIST THROUGH THE TAF PERIOD
UNDER MOSTLY CLEAR SKIES. AT KIPL, CURRENT S-SW WINDS WILL SHIFT
OUT OF THE WEST BY SUNSET TONIGHT. SUNDOWNER WIND GUSTS OF 20-25
KT WILL BE LIKELY LATER THIS EVENING FOR A FEW HOURS BETWEEN
01-06Z. AT KBLH, WINDS WILL FAVOR A S-SW COMPONENT WITH 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 WARNING FROM 10 AM TUESDAY TO 8 PM MST THURSDAY FOR
AZZ530>534-536>551-553>555-559-560-562.
CA...EXTREME HEAT WARNING FROM 10 AM TUESDAY TO 8 PM PDT THURSDAY FOR
CAZ562-564>570.
SHORT TERM...RW
LONG TERM...KUHLMAN/RW
AVIATION...SALERNO/BENEDICT
FIRE WEATHER...KUHLMAN
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