795
FXUS65 KPSR 151737
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1036 AM MST SAT AUG 15 2026
UPDATE
18Z AVIATION DISCUSSION.
KEY MESSAGES.
- DRY CONDITIONS, PARTLY CLOUDY SKIES, AND NEAR NORMAL TEMPERATURES
ARE EXPECTED THIS WEEKEND.
- EXTREME HEAT WATCHES HAVE BEEN ISSUED FOR THE LOWER DESERTS OF
SOUTHEAST CALIFORNIA AND SOUTHERN AND CENTRAL ARIZONA FOR MUCH
OF NEXT WEEK.
SHORT TERM /TODAY THROUGH SUNDAY/
THE INFLUENCE OF THE UPPER LEVEL TROUGH THAT BROUGHT COOLER
CONDITIONS OVER THE PAST SEVERAL DAYS IS WAINING AS IT CONTINUES
TO WEAKEN AND RETROGRADE TO THE NORTHWEST. MOISTURE LEVELS ACROSS
THE REGION HAVE FALLEN TO SLIGHTLY BELOW NORMAL ACROSS MUCH OF
ARIZONA WHILE SLIGHTLY ELEVATED MOISTURE LEVELS LINGER ACROSS
SOUTHERN CALIFORNIA. THESE MOISTURE LEVELS ARE EXPECTED TO STAY
FAIRLY STABLE THROUGH THE REST OF THE WEEKEND AND LIKELY FOR MUCH
OF NEXT WEEK. THE SUBTROPICAL RIDGE CURRENTLY CENTERED OVER THE
LOWER MS RIVER VALLEY IS SLATED TO GRADUALLY SHIFT WESTWARD OVER
THE NEXT SEVERAL DAYS, EVENTUALLY BECOMING FULLY ENTRENCHED ACROSS
THE SOUTHWESTERN U.S. BY AROUND TUESDAY. THE OVERALL LACK OF
DECENT MONSOON MOISTURE IN COMBINATION WITH INCREASING SUBSIDENCE
FROM THE INCOMING RIDGE WILL MOSTLY INHIBIT CONVECTIVE POTENTIAL
ACROSS OUR AREA THIS WEEKEND AND LIKELY WELL INTO NEXT WEEK.
AS HEIGHTS INCREASE OVER THE REGION TODAY INTO SUNDAY, WARMING
CONDITIONS WILL PUSH DAYTIME HIGHS BACK INTO THE NORMAL RANGE.
PERIODS OF HIGHER CLOUDS, AT TIMES SOMEWHAT THICK, SHOULD HELP TO
TAKE THE EDGE OFF THE AFTERNOON TEMPERATURES THIS WEEKEND, BUT
PROBABLY NOT ENOUGH TO KEEP LOWER DESERT HIGHS FROM REACHING 105
DEGREES IN MOST SPOTS.
LONG TERM /MONDAY THROUGH FRIDAY/.
THE WEATHER PATTERN FOR NEXT WEEK WILL SEE THE SUBTROPICAL HIGH
BECOMING THE DOMINATE FEATURE ACROSS THE SOUTHWESTERN U.S. WHILE
ITS STRENGTH WILL BARELY CHANGE. GUIDANCE AGREES THE RIDGE CENTER
WILL SHIFT FROM TEXAS ON MONDAY TO SOMEWHERE OVER ARIZONA ON
TUESDAY WITH H5 HEIGHTS RISING TO 595-597DM. H5 HEIGHTS OF THIS
MAGNITUDE WILL REPRESENT THE 97TH PERCENTILE OF CLIMATOLOGY FOR
THE PERIOD AND TEMPERATURES WILL FOLLOW WITH FORECAST HIGHS ONLY
FALLING SHORT OF DAILY RECORDS BY A FEW DEGREES STARTING MONDAY.
SINCE MOISTURE LEVELS ARE NOW EXPECTED TO REMAIN FAIRLY LIMITED
FOR MUCH IF NOT ALL OF NEXT WEEK, THE DAY-TO-DAY CONVECTIVE
POTENTIAL SHOULD REMAIN QUITE LOW AND LIKELY CONFINED TO FAR
EASTERN ARIZONA. THE MOST LIKELY SCENARIO KEEPS THE RIDGE IN FULL
CONTROL OVER THE DESERT SOUTHWEST WITH THE CENTER HOVERING
SOMEWHERE OVER ARIZONA AND/OR INTO WESTERN NEW MEXICO.
FORECAST CONFIDENCE FOR A MORE PROLONGED HEAT EVENT HAS INCREASED
LEADING US TO EXPAND THE EXTREME HEAT WATCH THROUGH SOUTHWEST
ARIZONA AND MUCH OF SOUTHEAST CALIFORNIA, WHILE EXTENDING THE
TIMEFRAME THROUGH NEXT FRIDAY. NBM FORECAST HIGHS SHOW READINGS
ANYWHERE FROM 108-113 DEGREES ACROSS THE LOWER DESERTS EACH DAY
NEXT WEEK WITH OVERNIGHT LOWS INCHING TOWARD THE 90 DEGREE MARK AS
EARLY AS TUESDAY AS SURFACE DEW POINTS SHIFT A BIT HIGHER.
FORECAST MAJOR HEATRISK HAS ALSO EXPANDED MORE ACROSS THE WESTERN
LOWER DESERTS GOING INTO THE MIDDLE PART OF NEXT WEEK WITH THE
BULK OF THE AREA KEEPING MAJOR HEATRISK LEVELS THROUGH AT LEAST
NEXT FRIDAY. THERE IS UNCERTAINTY IN THE LENGTH OF TIME THIS HEAT
EVENT WILL LAST AS SOME OF THE GUIDANCE SHOWS THE RIDGE CENTER
MAY EVENTUALLY SHIFT MORE TO THE NORTH. IF THIS OCCURS, IT SHOULD
HELP TO INCREASE THE AMOUNT OF MONSOON ACTIVITY OVER THE REGION,
EVENTUALLY LEADING TO SOME DEGREE OF COOLING.
AVIATION
UPDATED AT 1730Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NO AVIATION WEATHER CONCERNS ARE EXPECTED THROUGHOUT THE FORECAST
PERIOD UNDER INCREASING MID/HIGH CLOUD DECKS. THE OVERALL WIND
PATTERN WILL EXHIBIT TYPICAL DIURNAL TENDENCIES WITH SPEEDS
REMAINING AOB 10 KTS. A LATER THAN USUAL EASTERLY SHIFT IS
ANTICIPATED AT KPHX AND KIWA TONIGHT.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO AVIATION WEATHER CONCERNS ARE ANTICIPATED THROUGHOUT THE TAF
PERIOD UNDER INCREASING MID/HIGH CLOUD DECKS. WINDS WILL FLUCTUATE
BETWEEN SOUTHEAST TO WESTERLY AT KIPL AND SOUTHERLY TO SOUTHWESTERLY
AT KBLH, WITH MODEST AFTERNOON AND EARLY EVENING GUSTS.
FIRE WEATHER
DRIER CONDITIONS AND NEAR NORMAL TEMPERATURES WILL PREVAIL THIS
WEEKEND BEFORE TEMPERATURES RISE TO ABOVE NORMAL NEXT WEEK. LITTLE
IF ANY MONSOON STORM ACTIVITY IS EXPECTED OVER THE NEXT SEVERAL
DAYS WITH ONLY ISOLATED AFTERNOON STORMS POSSIBLE OVER THE FAR
EASTERN DISTRICTS. HUMIDITY LEVELS WILL CONTINUE TO DROP WITH
AFTERNOON MINRHS FALLING INTO THE TEENS ACROSS THE LOWER DESERTS
TO AROUND 25% FOR HIGHER TERRAIN AREAS STARTING SUNDAY. EXPECT
OVERALL LIGHT WINDS GENERALLY FOLLOWING TYPICAL DIURNAL PATTERNS.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...EXTREME HEAT WARNING FROM 10 AM MONDAY TO 8 PM MST FRIDAY FOR
AZZ530>544-546-548>551-553>555-559.
CA...EXTREME HEAT WARNING FROM 10 AM MONDAY TO 8 PM PDT FRIDAY FOR
CAZ562-565>567-569-570.
SHORT TERM...KUHLMAN
LONG TERM...KUHLMAN
AVIATION...SALERNO
FIRE WEATHER...KUHLMAN
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