948
FXUS65 KPSR 040505
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1005 PM MST FRI JUL 3 2026
UPDATE
UPDATED AVIATION
KEY MESSAGES
- TEMPERATURES WILL CONTINUE TO WARM THROUGH NEXT WEEK REACHING
ABOVE NORMAL LEVELS BY MONDAY.
- AS THE HEAT BUILDS, MODERATE HEAT RISK WILL INCREASE WITH LOWER
ELEVATION HIGHS REACHING 110 DEGREES FOR MUCH OF NEXT WEEK.
- DRY CONDITIONS WILL PREVAIL, ALTHOUGH A SPRINKLE CANNOT BE RULED
OUT SATURDAY INTO SUNDAY, BEFORE ISOLATED STORM CHANCES RETURN OVER
THE ARIZONA HIGH TERRAIN BY THE MIDDLE OF NEXT WEEK.
SHORT TERM /TODAY THROUGH SUNDAY/
SUBTROPICAL HIGH PRESSURE HAS NUDGED INTO THE REGION, WITH 594DAM
HEIGHTS CENTERED OVER SOUTHERN NM AND 590-592DAM HEIGHTS OVER THE
LOCAL AREA. THIS INCREASE IN HEIGHTS OVER THE AREA HAS YIELDED A
WARMING OF TEMPERATURES. MIDDAY TEMPERATURES WERE RUNNING AROUND 2-5
DEGREES WARMER THAN THE SAME TIME YESTERDAY AND WITH THIS WARMING,
AFTERNOON HIGH TEMPERATURES ARE FORECAST TO BE AROUND SEASONAL
AVERAGES, WITH LOWER DESERT HIGHS IN THE 104-107F RANGE.
SOME HIGH-LEVEL CLOUDS HAVE BEGUN SPREADING INTO THE REGION. MUCH OF
THIS IS MOISTURE SHEDDING OFF OF FORMER TROPICAL SYSTEM DOUGLAS.
CLOUDS WILL CONTINUE TO STREAM INTO THE REGION FROM THE SOUTHWEST
AND THICKEN, THROUGH THIS WEEKEND AS REMNANT MIDLEVEL VORTICITY IS
ALSO SHOWN TO MOVE NORTH TOWARD L.A. LATER ON SATURDAY WITH A WEAK
SHORTWAVE PROGRESSING ACROSS AZ. PWATS WILL GO FROM ABNORMAL DRY AT
AROUND 0.3" TODAY TO SEASONAL LEVELS, 0.9-1.1", BY THE END OF THE
DAY SATURDAY. THIS MOISTURE FLUX WILL BE CONFINED TO THE MID AND
UPPER LEVELS, WITH DRY AIR PERSISTING BELOW 700MB. DEW POINT
TEMPERATURES WILL HARDLY BUDGE FROM TODAY TO TOMORROW. THE MOISTURE
ALOFT WILL BE DEEP ENOUGH TO SUPPORT SPOTTY LIGHT SHOWERS SATURDAY,
BUT WITH THE DRY SUB-CLOUD LAYER MOST PRECIPITATION OVER THE LOWER
DESERTS WILL EVAPORATE BEFORE REACHING THE GROUND. THERE WILL BE
BETTER CHANCES FOR SHOWERS AND EVEN LIGHT RAINFALL ACCUMULATION OVER
HIGHER ELEVATIONS OF NORTHERN AZ. SPRINKLES HAVE AT LEAST BEEN ADDED
TO THE FORECAST FOR PORTIONS OF SOUTH-CENTRAL AZ. THE CHANCES OF
GETTING A LIGHTNING STRIKE OUT OF THIS ACTIVITY IS VERY LOW (<5%),
DUE TO VERY LOW INSTABILITY. HEADING INTO SUNDAY CLOUD COVER WILL
GRADUALLY SCATTER OUT AS THE WEAK SHORTWAVE AND LIFT PROGRESSES OFF
TO THE NORTH.
THE THICKER CLOUDS SATURDAY WILL LIKELY MODERATE THE SURFACE
TEMPERATURES TO A DEGREE, LIMITING THE SOLAR RADIATION. LATEST NBM
FORECAST HIGHS HAVE TRENDED A DEGREE COOLER ON SATURDAY THAN
PREVIOUS FORECASTS, BUT IT WOULD NOT BE SURPRISING TO SEE HIGHS FAIL
TO REACH 105F, ESPECIALLY ACROSS SOUTH-CENTRAL AZ. THE ADDED CLOUD-
COVER WILL ALSO HELP INSULATE MORNING TEMPERATURES SATURDAY MORNING,
WITH LOWS LIKELY STAYING IN THE 80S IN A FEW SPOTS. WITH MORE SUN
MIXING IN ON SUNDAY, AND THE GRADUAL WARMING ATMOSPHERE, SURFACE
TEMPERATURES WILL LIKELY RUN A FEW DEGREES WARMER THAN SATURDAY. A
FEW LOWER DESERT SPOTS WILL EVEN NEAR 110F, INCLUDING IN PHOENIX
WHERE THERE IS AROUND 30-50% ODDS OF REACHING THE MARK. BESIDES THE
HEAT, AND POTENTIAL WET STUFF FALLING FROM THE SKY, WINDS WILL
REMAIN SEASONALLY BREEZY IN THE AFTERNOONS THROUGH THE WEEKEND, WITH
GUSTS MOSTLY UP TO 15-20 MPH.
LONG TERM /MONDAY THROUGH THURSDAY/
THE WEATHER PATTERN IS EXPECTED TO GRADUALLY SHIFT MORE INTO A
MONSOON PATTERN STARTING NEXT WEEK. HOWEVER, A GOOD DEAL OF
UNCERTAINTY REMAINS WITH THE POSITIONING OF THE SUBTROPICAL RIDGE
AND THUS THE AMOUNT OF SUBSIDENCE, AND WHETHER OR NOT MUCH MOISTURE
WILL ADVECT INTO THE AREA. THE RIDGE IS EXPECTED TO STRENGTHEN EARLY
NEXT WEEK AND BRIEFLY FORM A CENTER SOMEWHERE ALONG THE ARIZONA/NEW
MEXICO BORDER, BUT GUIDANCE IS NOW LEANING TOWARD THE CENTER OF THE
HIGH EVENTUALLY SHIFTING WESTWARD TO OFF THE SOUTHERN CALIFORNIA
COAST BY AROUND THURSDAY. AT LEAST FOR A BRIEF PERIOD BEFORE
POTENTIALLY REPOSITIONING AGAIN BACK TOWARD THE FOUR CORNERS TOWARD
NEXT WEEKEND.
H5 HEIGHTS ARE STILL EXPECTED TO FALL WITHIN SEASONAL NORMALS ON
MONDAY, BUT SOME STRENGTHENING TUESDAY INTO WEDNESDAY IS LIKELY TO
PUSH HEIGHTS ABOVE THE 90TH PERCENTILE. THE MORE FAVORABLE
POSITIONING OF THE HIGH BY MONDAY SHOULD ALSO ALLOW FOR SOME MODEST
GULF OF CALIFORNIA MOISTURE SURGES, POTENTIALLY LEADING TO SURFACE
DEW POINTS NEARING 50 DEGREES AND LOW LEVEL MIXING RATIOS OF 6-7
G/KG. ALTHOUGH THIS MOISTURE WILL BE AN IMPROVEMENT, IT WILL NOT BE
ENOUGH TO COUNTERACT THE SUBSIDENCE FROM THE RIDGE, AT LEAST ON
MONDAY. SOME FURTHER IMPROVEMENT IN MOISTURE OVER THE EASTERN
ARIZONA HIGH TERRAIN INTO THE MIDDLE OF NEXT WEEK SHOULD FINALLY
ALLOW FOR SOME ISOLATED CONVECTION, BUT AS OF NOW IT DOES NOT LOOK
TO BE MUCH MORE THAN 10-20% CHANCES.
THE BIGGER FORECAST CONCERN NEXT WEEK WILL BE THE WIDESPREAD
MODERATE HEATRISK DEVELOPING BY TUESDAY AND POTENTIALLY SOME AREAS
OF MAJOR HEATRISK. ENSEMBLE PEAK H5 HEIGHTS OF 594-596DM LOOK TO
OCCUR ON TUESDAY INTO EARLY WEDNESDAY AND THIS SHOULD LEAD TO
DAYTIME HIGHS RISING INTO A 110-115 DEGREE RANGE BOTH DAYS, WITH
ODDS OF EXCEEDING 115F AT 30-50% IN SOME LOCATIONS, INCLUDING
PHOENIX. OVERNIGHT LOWS WILL ALSO TREND UPWARD WITH MANY LOCATIONS
STAYING IN THE 80S AND POTENTIALLY NEAR 90 DEGREES IN CENTRAL
PHOENIX. GUIDANCE THEN INDICATES LOWERING HEIGHTS OVER AT LEAST
ARIZONA LATER NEXT WEEK AS THE RIDGE CENTER SHIFTS WEST
SOUTHWESTWARD TO OFF THE COAST OF CALIFORNIA. IF THIS OCCURS, IT
SHOULD SHAVE OFF 2-3 DEGREES FROM OUR HIGHS BY NEXT FRIDAY.
AVIATION
UPDATED AT 0505Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NO SIGNIFICANT WEATHER CONCERNS WILL EXIST THROUGH SATURDAY NIGHT
UNDER PERIODS OF THICKER MID/HIGH CIGS. WITH THESE CIGS, EXPANSIVE
VIRGA AND POTENTIALLY AN ISOLATED SHRA WILL BE LIKELY DURING
DAYLIGHT HOURS SATURDAY, BUT WITH LIMITED IMPACT TO OPERATIONS.
TRENDS IN WIND SHIFTS AND SPEEDS SHOULD BE SIMILAR TO THE PAST 24
HOUR WITH MINIMAL AFTERNOON GUSTINESS.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO MAJOR WEATHER CONCERNS WILL EXIST THROUGH SATURDAY NIGHT UNDER
PERIOD OF THICKER MID/HIGH CIGS, OCCASIONAL VIRGA, AND POTENTIALLY
AN ISOLATED SHRA. CHANCES FOR OPERATIONAL IMPACTS FROM CIGS/SHRA ARE
TOO LOW TO INCLUDE IN THIS TAF PACKAGE. CONFIDENCE IS GOOD THAT
WINDS WILL GENERALLY SHIFT BETWEEN SE AND SW WITH MODEST
AFTERNOON/EARLY EVENING GUSTINESS. PERIODS OF NEAR CALM CONDITIONS
MAY BE COMMON SATURDAY MORNING.
FIRE WEATHER
BUILDING HIGH PRESSURE OVER THE NEXT SEVERAL DAYS WILL LEAD TO
WARMING TEMPERATURES, EVENTUALLY LEADING TO ABOVE NORMAL
TEMPERATURES BY EARLY NEXT WEEK. WINDS WILL REMAIN FAIRLY LIGHT INTO
NEXT WEEK WITH ONLY THE TYPICAL AFTERNOON UPSLOPE/UPVALLEY 15-20 MPH
GUSTS AND MAINLY STARTING SUNDAY. AFTERNOON MINIMUM HUMIDITIES WILL
CONTINUE TO RANGE BETWEEN 5-10% THROUGH AT LEAST SATURDAY, WITH
OVERNIGHT RECOVERIES ONLY REACHING 15-30% THROUGH SATURDAY NIGHT,
BEFORE IMPROVING TO 10-15% STARTING SUNDAY. DESPITE THE DIMINISHED
WINDS, SEASONABLY ELEVATED FIRE DANGER WILL PERSIST THROUGH THE
WEEKEND DUE TO VERY DRY CONDITIONS AND VERY DRY AND RECEPTIVE FUELS.
MOISTURE IS STILL EXPECTED TO GRADUALLY INCREASE OVER THE REGION
DURING THE FIRST HALF OF NEXT WEEK, BUT OVERALL DRY CONDITIONS
SHOULD PERSIST.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM...BENEDICT
LONG TERM...KUHLMAN/BENEDICT
AVIATION...18
FIRE WEATHER...KUHLMAN
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