315
FXUS65 KPSR 131815
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1115 AM MST TUE OCT 13 2026
UPDATE
UPDATED AVIATION DISCUSSION.
KEY MESSAGES
- LINGERING RAIN CHANCES THIS MORNING WILL PUSH INTO THE EASTERN
ARIZONA HIGH TERRAIN THIS AFTERNOON BEFORE ENDING COMPLETELY
THIS EVENING.
- BELOW NORMAL TEMPERATURES ARE FORECAST THROUGH WEDNESDAY BEFORE
CREEPING BACK INTO THE NORMAL RANGE LATE WEEK.
- BREEZY TO WINDY CONDITIONS WILL IMPACT THE WESTERN DESERTS
THROUGH THURSDAY BEFORE SPREADING ACROSS THE REST OF SOUTHERN
AND CENTRAL ARIZONA BY FRIDAY. ADVISORY LEVEL WINDS WILL BE
POSSIBLE BY FRIDAY, PARTICULARLY ACROSS SOUTHEAST ARIZONA.
SHORT TERM /TODAY THROUGH WEDNESDAY/
LINGERING MOISTURE ASSOCIATED WITH A DEEP TROUGH CURRENTLY
CENTERED OVER NEVADA IS ALLOWING FOR A CONTINUATION OF ISOLATED
SHOWERS ACROSS CENTRAL AND EASTERN ARIZONA EARLY THIS MORNING. THE
TROUGH HAS HUNG AROUND SLIGHTLY LONGER THAN PREVIOUSLY ADVERTISED
WHICH IN TURN HAS ALLOWED FOR A BIT MORE SHOWER ACTIVITY THAN
FORECAST YESTERDAY. ADDITIONAL RAINFALL AMOUNTS OVER THE PAST 12
HOURS HAVE RANGED FROM UP TO AROUND 0.10" ACROSS MUCH OF MARICOPA
COUNTY TO AS MUCH AS 0.25-0.50" IN FAR EASTERN AND NORTHERN AREAS
OF PHOENIX AND INTO THE FOOTHILLS NORTH AND NORTHEAST OF PHOENIX.
ANOTHER ROUND OF SHOWERS IS EXPECTED TO MOVE THROUGH THE PHOENIX
AREA THROUGH SUNRISE WITH SHOWERS PERSISTING ACROSS THE EASTERN
ARIZONA HIGH TERRAIN THROUGH AT LEAST EARLY AFTERNOON. ADDITIONAL
LOCALIZED AMOUNTS UP TO AROUND 0.25" WILL BE POSSIBLE.
DRIER AIR IS GRADUALLY WORKING INTO WESTERN PORTIONS OF THE AREA
AND THIS SHOULD WORK THROUGH THE REST OF ARIZONA BY THIS EVENING.
THE COOLER AIR MASS WILL KEEP THE BULK OF THE AREA IN THE 70S
TODAY WITH OVERNIGHT LOWS DIPPING INTO THE 50S TONIGHT UNDER CLEAR
TO MOSTLY CLEAR SKIES. SIMILAR HIGHS ARE EXPECTED FOR WEDNESDAY,
BUT WITH SOME WESTERN DESERT LOCATIONS TOPPING 80 DEGREES AS
RIDGING BEGINS TO WORK INTO THE AREA FROM THE WEST. THE EXITING OF
THE DEEP TROUGH WILL ALSO BRING LOCALLY WINDY CONDITIONS ACROSS
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA FROM THIS AFTERNOON
THROUGH WEDNESDAY.
LONG TERM /THURSDAY THROUGH MONDAY/
FORECAST CONFIDENCE IS INCREASING FOR ADVISORY LEVEL WINDS
DEVELOPING LATER THIS WEEK ACROSS EASTERN AND SOUTHERN ARIZONA.
GUIDANCE CONTINUES TO SHOW A FAST MOVING DRY SHORTWAVE TROUGH
DIVING SOUTHWESTWARD INTO THE WESTERN PART OF THE LARGE SCALE
TROUGH LINGERING ACROSS THE SOUTHWESTERN U.S. WEDNESDAY NIGHT
INTO THURSDAY. THIS DISTURBANCE IS THEN EXPECTED TO FORM A CUT-
OFF LOW JUST TO OUR SOUTHWEST AT THE SAME TIME STRONG RIDGING
EDGES INTO CALIFORNIA AND THE GREAT BASIN.
THURSDAY LOOKS TO BE A TRANSITION DAY WITH A CONTINUATION OF
ENHANCED NORTHERLY WINDS DOWN THE LOWER CO RIVER VALLEY WHILE
TEMPERATURES WARM CLOSER TO NORMALS AS NORTHERLY DOWNSLOPE
WARMING SPREADS THROUGH MUCH OF ARIZONA. THESE NORTHERLY WINDS
SHOULD QUICKLY SHIFT OUT OF THE EAST LATE THURSDAY NIGHT/FRIDAY
MORNING AS THE CUT-OFF LOW FORMS AND DRIFTS SOUTHWESTWARD OFF THE
COAST OF BAJA. A STRONG PRESSURE GRADIENT WILL THEN DEVELOP ACROSS
ARIZONA BETWEEN THE CUT-OFF LOW TO THE SOUTHWEST AND THE RIDGE TO
OUR NORTH RESULTING IN INCREASING EASTERLY WINDS FRIDAY MORNING.
GUIDANCE SHOWS 30-45 KT H8 WINDS SETTING UP ACROSS SOUTHERN
ARIZONA FRIDAY MORNING WHICH SHOULD TRANSLATE TO WIDESPREAD 30-40
MPH GUSTS AT TIMES TO AS HIGH AS 45 MPH ACROSS PORTIONS OF PINAL
AND SOUTHERN MARICOPA COUNTIES. A WIND ADVISORY IS EXPECTED TO BE
NEEDED FOR THESE AREAS ON FRIDAY AND POSSIBLY INTO SATURDAY
MORNING BEFORE THE GRADIENT BEGINS TO RELAX.
THE STRONG EASTERLY WINDS ON FRIDAY WILL ALSO USHER IN SOME COOLER
AIR FROM NEW MEXICO, KEEPING DAYTIME HIGHS IN THE LOW TO MID 80S
ACROSS THE PHOENIX AREA. THE WESTERN LOWER DESERTS WILL BE LESS
AFFECTED BY THIS BACK-DOOR COOL FRONT WITH HIGHS CLOSER TO 90
DEGREES.
MODEL UNCERTAINTY INCREASES FOR THE WEEKEND AS THERE IS SOME
QUESTION OF HOW LONG THE CUT-OFF LOW WILL SIT JUST TO OUR SOUTH
BEFORE EJECTING BACK TO THE EAST AND WHETHER OR NOT THE REMNANTS
OF TC SIMON WILL PLAY ANY ROLE IN OUR WEATHER. AS OF RIGHT NOW,
GUIDANCE SHOWS THE CUT-OFF WEAKENING AND SHIFTING EAST NORTHEAST
ACROSS NORTHERN MEXICO LATER SATURDAY INTO SUNDAY WHILE THE
REMNANTS OF SIMON MOSTLY LIKELY BYPASSES OUR REGION TO THE
SOUTHEAST. BEFORE THIS OCCURS, THE POSITIONING OF THE CUT-OFF LOW
AND THE INCREASED EASTERLY FLOW IS EXPECTED TO BRING GOOD MID AND
UPPER LEVEL MOISTURE ADVECTION INTO ARIZONA AND SOUTHERN
CALIFORNIA ON FRIDAY, BUT LIKELY LITTLE IF ANY LOW LEVEL MOISTURE.
THE MOST LIKELY SCENARIO CALLS FOR INCREASED HIGHER LEVEL CLOUDS
ON SATURDAY AND A 10-20% CHANCE OF SHOWERS FOCUSED MORE TOWARD
SOUTHEAST ARIZONA. HOWEVER, THERE ARE SOME ENSEMBLE MEMBERS (MAYBE
20%) THAT TRY TO PULL BETTER LOW LEVEL MOISTURE (EVEN POTENTIALLY
FROM SIMON'S REMNANTS) INTO AT LEAST SOUTHEAST ARIZONA SATURDAY
INTO EARLY SUNDAY. IF THIS WERE TO OCCUR, IT WOULD BRING MUCH
BETTER RAIN CHANCES AS FAR NORTHWEST AS THE PHOENIX AREA.
ALTHOUGH STILL UNLIKELY, IT WILL BE SOMETHING TO WATCH OVER THE
NEXT FEW DAYS. BY EARLY NEXT WEEK, WE SHOULD HAVE ANOTHER RIDGE
WITH DRY AIR ADVECTION MOVING IN FROM THE WEST LEADING TO QUIETER
WEATHER CONDITIONS.
AVIATION
UPDATED AT 1815Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
THE PRIMARY AVIATION WEATHER CONCERN WILL CONTINUE TO BE LINGERING
SHOWERS WITH LOW CIGS THROUGH THIS AFTERNOON. SHOWERS WILL
CONTINUE INTO THIS AFTERNOON, RESULTING IN LOWERED CIGS DOWN TO
AROUND 1-3 KFT, ALONG WITH BRIEF MVFR VISIBILITIES, AT TIMES
PRIMARILY AT KIWA, KSDL, AND KDVT. EXPECT SOME IMPROVEMENT IN
CIGS WITH SCT-BKN BASES GENERALLY AOA 3-5 KFT THIS AFTERNOON
BEFORE CLEARING OUT THIS EVENING. WESTERLY WINDS WILL INCREASE
INTO THIS AFTERNOON WITH A FEW GUSTS AROUND 15-20 KTS. WINDS
WEAKEN THIS EVENING BEFORE BECOMING LIGHT AND VARIABLE TONIGHT
INTO THE OVERNIGHT PERIOD.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO MAJOR AVIATION WEATHER CONCERNS ARE ANTICIPATED THROUGH THE
NEXT 24 HOURS UNDER MOSTLY CLEAR SKIES. WINDS WILL FAVOR THE W TO
NW AT KIPL, WHILE FAVORING THE N TO NW AT KBLH. A FEW GUSTS TO
AROUND 20 KTS ARE EXPECTED AT KBLH, TAPERING OFF THIS EVENING.
FIRE WEATHER
ISOLATED SHOWERS WILL PERSIST ACROSS THE EASTERN DISTRICTS FOR THE
FIRST PART OF TODAY BEFORE DRIER AIR SWEEPS THROUGH THE AREA
BEHIND A PASSING COLD FRONT. ELEVATED MOISTURE LEVELS WILL KEEP
MINRHS TODAY BETWEEN 25-35% FOR THE WESTERN DISTRICTS TO 40-70%
FOR THE EASTERN DISTRICTS BEFORE LOWERING DOWN TO 20-40%
WEDNESDAY. NORTHERLY BREEZY WINDS WILL DEVELOP ACROSS SOUTHEAST
CA AND SOUTHWEST AZ TODAY AND STRENGTHEN EACH DAY THROUGH THURSDAY
BEFORE STRONG EASTERLY WINDS SPREAD THROUGH THE REGION BY FRIDAY.
BELOW NORMAL TEMPERATURES THROUGH WEDNESDAY WILL EVENTUALLY RETURN
TO NEAR NORMAL TEMPERATURES LATE WEEK. SOME MOISTURE RETURN FRIDAY
INTO THE WEEKEND MAY BRING LOW-END RAIN CHANCES BY SATURDAY.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM...KUHLMAN
LONG TERM...KUHLMAN
AVIATION...SMITH
FIRE WEATHER...KUHLMAN
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