475
FXUS65 KPSR 141733
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1033 AM MST FRI AUG 14 2026
UPDATE
UPDATED 18Z AVIATION
KEY MESSAGES.
- A FEW ISOLATED SHOWERS AND THUNDERSTORMS WILL REMAIN POSSIBLE
MAINLY DURING THE AFTERNOON HOURS TODAY ACROSS THE LOWER
COLORADO RIVER VALLEY.
- NEAR TO BELOW NORMAL TEMPERATURES ARE FORECAST THROUGH SATURDAY
BEFORE HEATING BACK UP INTO EARLY NEXT WEEK AS OVERALL DRY
CONDITIONS PERSIST.
- AN EXTREME HEAT WATCH HAS BEEN ISSUED FOR MARICOPA AND PINAL
COUNTIES FOR NEXT MONDAY THROUGH WEDNESDAY.
SHORT TERM /TODAY THROUGH SATURDAY/
BROAD UPPER LEVEL TROUGHING STILL RESIDES OVER THE WEST COAST
STATES, WHILE THE SUBTROPICAL RIDGE REMAINS CENTERED OVER THE
LOWER MS VALLEY. GRADUAL DRYING FROM WEST TO EAST IS STILL ONGOING
WITH GUIDANCE SHOWING LOW LEVEL MIXING RATIOS BETWEEN 8-10 G/KG
TODAY DROPPING TO 7-8 G/KG SATURDAY. THE TROUGH IS ALSO PROVIDING
A STEADY STREAM OF HIGHER LEVEL MOISTURE AND CLOUDS BLANKETING
SOUTHERN CALIFORNIA WHILE SOUTHERN AND CENTRAL ARIZONA SEES PARTLY
CLOUDY SKIES. WITH THE VERY MARGINAL MOISTURE REMAINING IN PLACE
AND FAR FROM OPTIMAL INSOLATION EXPECTED LATER THIS MORNING AND
AFTERNOON, THE CONVECTIVE POTENTIAL IS EXPECTED TO DROP FURTHER.
HI-RES CAMS STRUGGLED A BIT YESTERDAY, ESPECIALLY WITH THE CLOUDS
IMPACTING HEATING AND IT SEEMS TO BE A SIMILAR SITUATION FOR
TODAY. CAMS ARE TRYING TO SHOW SOME SHOWERS AND STORMS FORMING
WITHIN THE LOWER CO RIVER VALLEY THIS AFTERNOON, BUT EXTENSIVE
CLOUD COVER SHOULD PREVAIL OVER THAT AREA WELL INTO THE AFTERNOON.
IT SEEMS LIKELY THE CAMS ARE OVERDOING THE CONVECTIVE POTENTIAL AS
THEY DID YESTERDAY, SO POPS REMAIN UNDER 20% FOR THE WESTERN
DESERTS. ONLY WIDELY ISOLATED SHOWERS AND MAYBE A FEW WEAK
THUNDERSTORMS ARE EXPECTED ACROSS SOUTH-CENTRAL AND EASTERN
ARIZONA THIS AFTERNOON.
THE ADDITIONAL DRYING FORECAST FOR SATURDAY SHOULD SHUT DOWN THE
CONVECTIVE POTENTIAL FOR ALL BUT THE FAR EASTERN AND NORTHERN
ARIZONA HIGH TERRAIN. WE ALSO EXPECT THE STREAM OF UPPER LEVEL
CLOUDS TO SHIFT MORE INTO ARIZONA ON SATURDAY LEAVING MOSTLY
CLOUDY SKIES FOR MUCH OF OUR AREA. SINCE THE TROUGH WILL HANG
AROUND TODAY AND TO A DEGREE THROUGH SATURDAY, TEMPERATURES WILL
BE SLOW TO WARM WITH HIGHS AT OR JUST ABOVE 100 DEGREES TODAY AND
MAYBE CLOSER TO 105 DEGREES SATURDAY DEPENDING ON THE CLOUD COVER.
LONG TERM /SUNDAY THROUGH THURSDAY/.
THE MAIN CONCERN FOR NEXT WEEK REMAINS THE BUILDING HEAT AS THE
SUBTROPICAL RIDGE GRADUALLY SHIFTS WESTWARD BACK OVER OUR REGION
BEGINNING SUNDAY. H5 HEIGHTS ARE EXPECTED TO CLIMB FROM 588-591DM
ON SATURDAY TO 594-596DM SUNDAY BEFORE PEAKING ON TUESDAY AT
AROUND 596-597DM. FORECAST H5 HEIGHTS MONDAY THROUGH AT LEAST
WEDNESDAY FALL CLOSE TO THE 97TH PERCENTILE OF CLIMATOLOGY FOR THE
PERIOD, BUT FORECAST HIGHS REMAIN AT LEAST A FEW DEGREES BELOW
RECORDS. AN EXTREME HEAT WATCH REMAINS IN EFFECT FOR MONDAY-
WEDNESDAY FOR THE SOUTH-CENTRAL ARIZONA LOWER DESERTS AND ITS VERY
PLAUSIBLE IT MAY NEED TO GO THROUGH THE REST OF THE WORKWEEK AS
THE RIDGE IS NOT LIKELY TO WEAKEN OR MOVE MUCH LATE NEXT WEEK. THE
LATEST NBM FORECAST TEMPERATURES FOR LATE NEXT WEEK HAVE ALSO
BEEN TRENDING UP, BASICALLY KEEPING HIGHS AROUND 110 DEGREES. THE
MAIN QUESTION ABOUT THE HEAT WILL BE THE AMOUNT OF CONVECTION
THAT MAY FORM OVER EASTERN ARIZONA POTENTIALLY BRING OUTFLOWS
INTO THE LOWER DESERTS AND/OR DEBRIS CLOUDS. GUIDANCE DOES AGREE
SOME MODEST MOISTURE ADVECTION IS EXPECTED EARLY NEXT WEEK, BUT IT
SHOULD ONLY BE ENOUGH TO HELP HIGHER TERRAIN AREAS. AS OF RIGHT
NOW, THERE ARE NO CLEAR SIGNS THE CONVECTIVE POTENTIAL WILL BE
ENOUGH TO GREATLY AFFECT TEMPERATURES EARLY NEXT WEEK, SO MORE
THAN LIKELY THE CURRENT FORECAST HIGHS OF AROUND 110 DEGREES WILL
HOLD.
AVIATION
UPDATED AT 1735Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NO MAJOR AVIATION WEATHER CONCERNS ARE EXPECTED THROUGHOUT THE TAF
PERIOD UNDER MID TO HIGH LEVEL CLOUDS. THE OVERALL WIND PATTERN
WILL EXHIBIT THE TYPICAL DIURNAL TENDENCIES WITH SPEEDS GENERALLY
AOB 10KTS. CONFIDENCE IS GOOD THAT THUNDERSTORM ACTIVITY/OUTFLOWS
WILL REMAIN WELL REMOVED FROM THE TERMINALS TODAY.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
ISOLATED THUNDERSTORM ACTIVITY LATER THIS AFTERNOON, RESULTING IN
GUSTY AND ERRATIC WINDS WILL BE THE MAIN AVIATION WEATHER CHALLENGE
THROUGHOUT THE TAF PERIOD. WINDS WILL GENERALLY FLUCTUATE BETWEEN
THE SOUTHEAST TO SOUTHWEST WITH OVERALL SPEEDS AOB 10 KTS, ALTHOUGH
SOME MODEST AFTERNOON GUSTS IN THE MID TO UPPER TEENS WILL BE
POSSIBLE. ISOLATED THUNDERSTORM ACTIVITY IS POSSIBLE DURING THE MID
TO LATE AFTERNOON, WITH A LOW PROBABILITY (10-20%) OF DIRECT IMPACTS
TO THE TERMINALS WITH THE MORE LIKELY IMPACT BEING GUSTY OUTFLOW
WINDS.
FIRE WEATHER
GRADUAL DRYING CONDITIONS WILL PREVAIL OVER THE NEXT SEVERAL DAYS
WITH MONSOON STORM ACTIVITY NEARLY COMING TO AN END. HUMIDITY
LEVELS ARE SLATED TO DROP WHILE TEMPERATURES WARM BACK TO ABOVE
NORMAL BY SUNDAY. AFTERNOON MINRHS OF 25-35% TODAY WILL DROP INTO
THE TEENS ACROSS THE LOWER DESERTS TO AROUND 25% FOR HIGHER
TERRAIN AREAS STARTING SUNDAY. OVERNIGHT RECOVERIES WILL SHIFT
FROM GOOD THROUGH SATURDAY TO FAIR EARLY NEXT WEEK. WINDS WILL
REMAIN PREDOMINATELY OUT OF THE SOUTH SOUTHWEST MUCH OF THE PERIOD
WITH OVERNIGHT LIGHT EASTERLY DOWNSLOPING WINDS OVER THE EASTERN
DISTRICTS.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...EXTREME HEAT WATCH FROM MONDAY MORNING THROUGH WEDNESDAY EVENING
FOR AZZ534-537>544-546-548>551-553>555-559.
CA...NONE.
SHORT TERM...KUHLMAN
LONG TERM...KUHLMAN
AVIATION...LOJERO/FRIEDERS
FIRE WEATHER...KUHLMAN
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