399
FXUS65 KPSR 272123
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
223 PM MST SUN JUL 27 2025
KEY MESSAGES
- TEMPERATURES WILL CONTINUE TO WARM UP EARLY THIS WEEK PUSHING
DAILY HIGHS ACROSS THE LOWER DESERTS TO AROUND 110 DEGREES,
RESULTING IN WIDESPREAD MODERATE HEATRISK.
- A RETURN TO A MORE TYPICAL MONSOON PATTERN WILL ALLOW SHOWER
AND THUNDERSTORM ACTIVITY TO INCREASE FOR EASTERN PORTIONS OF
ARIZONA MONDAY INTO TUESDAY AND THEN INTO CENTRAL ARIZONA
WEDNESDAY INTO THURSDAY.
SHORT TERM /TODAY THROUGH TUESDAY/
THOUGH SOME MEASURE OF BROAD CYCLONIC FLOW WILL BE MAINTAINED TO
THE NORTHWEST OF THE REGION, GUIDANCE SHOWS MIDLEVEL NEGATIVE
HEIGHT ANOMALIES RETREATING WESTWARD AND OFFSHORE THROUGH THE NEXT
FEW DAYS, ALLOWING THE INFLUENCE OF THE HIGH PRESSURE (CURRENTLY
SPREAD OVER THE SOUTHEAST US AND SOUTHERN PLAINS) TO ENCROACH ON
EASTERN AZ. THIS WILL TURN FLOW ALOFT FROM ITS CURRENT DRY,
SOUTHWESTERLY CONFIGURATION TO SOUTHEASTERLY, AT LEAST OVER THE
EASTERN HALF OF THE STATE, BY MONDAY. AS LONG AS THIS MORE
TYPICAL MONSOON PATTERN IS MAINTAINED, A FAMILIAR EVOLUTION WILL
BEGIN TO TAKE PLACE, WITH MOSTLY ISOLATED CONVECTIVE ACTIVITY
ACROSS THE EASTERN AZ HIGH TERRAIN MONDAY BECOMING SOMEWHAT MORE
WIDESPREAD AND DRAWING CLOSER TO SOUTH-CENTRAL AZ TUESDAY AS
BETTER QUALITY MOISTURE CONTINUES TO BE IMPORTED. THE MAIN CONCERN
WITH CONVECTIVE ACTIVITY AT FIRST WILL BE STRONG, GUSTY WINDS
OVER THE EASTERN AZ HIGH TERRAIN MONDAY, WITH HIGH CLOUD BASES AND
INVERTED-V MODEL SOUNDINGS. BY TUESDAY, THE VALLEY STANDS A BETTER
CHANCE AT SEEING GUSTY OUTFLOW WINDS FROM NEARBY CONVECTIVE
ACTIVITY TO THE EAST/SOUTHEAST, THOUGH T-STORM DEVELOPMENT SHOULD
STILL OVERALL BE CONFINED TO HIGHER TERRAIN FEATURES.
AS HIGH PRESSURE SHIFTS WESTWARD OVER THE DESERT SOUTHWEST,
ENSEMBLE MEAN H5 HEIGHTS INCREASE TO A 591-595 DAM RANGE BY
MONDAY. THIS WILL LEAD TO WARMING TEMPERATURES INTO THE BEGINNING
OF THE WORKWEEK, THOUGH INCREASING MOISTURE OVER THE EASTERN CWA
SHOULD THEN TEMPER DAILY HIGHS AS THE WEEK GOES ON. LATEST NBM
SHOWS MONDAY AS THE WARMEST DAY OF THE UPCOMING WORKWEEK, WITH
MANY LOWER DESERT LOCATIONS NEARING 110F AND A FEW LIKELY
EXCEEDING 110F (90% CHANCE FOR 110+F AT PHOENIX SKY HARBOR
AIRPORT.)
LONG TERM /WEDNESDAY THROUGH SATURDAY/
MODEL UNCERTAINTY COMES MORE INTO PLAY FOR WEDNESDAY AND THURSDAY
AS GUIDANCE SHOWS A BIG DISPARITY AMONG MEMBERS FOR HOW MUCH AND
HOW FAR WEST THE MOISTURE WILL REACH INTO ARIZONA. THE GEFS IS
MUCH MORE OPTIMISTIC WITH HOW MUCH MOISTURE WILL MAKE ITS WAY INTO
SOUTH-CENTRAL ARIZONA STARTING WEDNESDAY AND THIS IS LARGELY IN
PART BECAUSE THE GFS SHOWS AN INVERTED TROUGH MOVING INTO FAR
SOUTHERN ARIZONA WHEREAS THE EURO MOSTLY KEEPS IT OVER SONORA
MEXICO. GIVEN THE DIFFERENCES, FORECAST CONFIDENCE REMAINS FAIRLY
LOW FOR THE POTENTIAL FOR MONSOON ACTIVITY INTO THE LOWER DESERTS
DURING THE MIDDLE PART OF THE WEEK. FOR NOW, NBM POPS SEEM
FAIRLY REASONABLE FOR WEDNESDAY AND THURSDAY WITH 15-25% CHANCES
OVER THE LOWER DESERTS OF MARICOPA COUNTY TO AS HIGH AS 50% WITHIN
GILA COUNTY. OTHER THAN THE POTENTIAL MOISTURE, THE SYNOPTIC SET-
UP DOES NOT LOOK VERY FAVORABLE AS WE ARE LIKELY TO BE NEAR OR
WITHIN THE RIGHT EXIT SUBSIDENT REGION OF A WEST TO EAST UPPER
LEVEL JET STREAMING OFF THE PACIFIC THROUGH CENTRAL CALIFORNIA. WE
WILL HOPEFULLY HAVE A BETTER IDEA ON THIS STORM POTENTIAL WITHIN
THE NEXT COUPLE DAYS.
THE SOUTHEASTERLY MOIST FLOW IS NOT LIKELY TO LAST LONG AS
GUIDANCE SHOWS THE CENTER OF THE SUBTROPICAL RIDGE SHIFTING OVER
SOUTHERN NEW MEXICO ON THURSDAY BEFORE POTENTIALLY SETTING UP
OVER FAR SOUTHERN ARIZONA AND NORTHERN MEXICO FRIDAY INTO NEXT
WEEKEND. THIS SHIFT WOULD LIKELY BRING IN DRIER WESTERLY FLOW AS
EARLY AS LATE THURSDAY OR EARLY FRIDAY, MOSTLY ENDING ANY RAIN
CHANCES FOR THE LOWER DESERTS ON FRIDAY. HIGHER TERRAIN AREAS OF
EASTERN ARIZONA WILL LIKELY STILL CONTINUE TO SEE DAILY CHANCES
INTO NEXT WEEKEND, BUT THE COVERAGE IS LIKELY TO BE SCALED BACK
QUITE A BIT.
TEMPERATURES FOR THE LATTER HALF OF THIS WEEK ARE NOT LIKELY TO
CHANGE ALL THAT MUCH WITH DAILY HIGHS MOSTLY RUNNING A COUPLE
DEGREES ABOVE NORMAL. HOWEVER, NBM GUIDANCE DOES SHOW A BIT OF AN
UPTICK IN TEMPERATURES BY NEXT WEEKEND AND THIS MAKES SENSE GIVEN
THE LIKELIHOOD OF DECREASING MOISTURE AND THE RIDGE CENTER MOVING
CLOSER TO OUR AREA. THE UPPER END OF GUIDANCE ALSO SHOWS SOME
POTENTIAL FOR HIGHS NEAR 115 DEGREES AND LOCALIZED MAJOR HEATRISK
FOR NEXT WEEKEND.
AVIATION
UPDATED AT 1741Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
WINDS WILL TEND TO FOLLOW TYPICAL DIURNAL TENDENCIES, WITH PERIODS
OF CALM AND LIGHT VARIABILITY DURING THE OVERNIGHT AND MORNING
HOURS. SPEEDS THIS AFTERNOON AND EVENING WILL INCREASE TO AROUND
10 KTS WITH OCCASIONAL 15-20 KT GUSTS. FEW TO SCT HIGH LEVEL
CLOUDS WILL CONTINUE THROUGH THE TAF PERIOD.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
WINDS AT KIPL WILL PREDOMINANTLY FAVOR THE WEST TO NORTHWEST, AND
SOUTH TO SOUTHWEST AT KBLH, WITH PERIODS OF LIGHT VARIABILITY IN
THE MORNING. SKC WILL PREVAIL.
FIRE WEATHER
TODAY WILL BRING ANOTHER DRY AND QUIET DAY BEFORE MOISTURE FINALLY
BEGINS TO CREEP BACK INTO EASTERN PORTIONS OF ARIZONA TONIGHT
INTO MONDAY. THIS SHOULD BRING SOME SCATTERED SHOWERS AND A FEW
THUNDERSTORMS MONDAY AFTERNOON ACROSS THE FAR EASTERN ARIZONA
HIGHER TERRAIN. EXPECT SLIGHTLY ABOVE NORMAL TEMPERATURES OVER THE
NEXT SEVERAL DAYS. WINDS WILL GENERALLY FOLLOW TYPICAL DIURNAL
TENDENCIES WITH SOME AFTERNOON UPSLOPE GUSTINESS. MINRHS WILL
CONTINUE TO RANGE FROM 5-10% AREAWIDE THROUGH MONDAY, WITH POOR
OVERNIGHT RECOVERIES OF 15-35%. MOISTURE AND RAIN CHANCES ARE THEN
LIKELY TO SPREAD WESTWARD INTO SOUTH-CENTRAL ARIZONA BY THE MIDDLE
OF NEXT WEEK WITH A MODEST INCREASE IN HUMIDITIES.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM...WHITTOCK
LONG TERM...KUHLMAN
AVIATION...BENEDICT
FIRE WEATHER...KUHLMAN
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