938
FXUS65 KPSR 151142
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
442 AM MST FRI MAY 15 2026
UPDATE
UPDATED AVIATION DISCUSSION.
KEY MESSAGES
- BREEZY TO LOCALLY WINDY CONDITIONS RETURN OVER THE WEEKEND,
WITH THE STRONGEST GUSTS ACROSS SOUTHEAST CALIFORNIA AND THE
ARIZONA HIGH TERRAIN.
- CRITICAL FIRE WEATHER CONDITIONS WILL BE POSSIBLE THIS WEEKEND,
PARTICULARLY ON SUNDAY FOR THE EASTERN ARIZONA HIGHER TERRAIN.
- AFTERNOON HIGH TEMPERATURES 4 TO 8 DEGREES ABOVE NORMAL THROUGH
SATURDAY WILL DROP INTO A NEAR TO BELOW NORMAL RANGE SUNDAY AND
EARLY NEXT WEEK.
SHORT TERM /TODAY THROUGH SUNDAY/
CLEAR SKIES ARE OBSERVED ACROSS MUCH OF THE REGION, AS A WEAK
DISTURBANCE SLOWLY TRACKS EASTWARD ACROSS AZ EARLY THIS MORNING.
WITH GENERALLY WEAK REGIONAL PRESSURE/TEMPERATURE GRADIENTS AND H5
HEIGHTS BEING MAINTAINED AROUND 582 DAM, ANTICIPATE ONLY MODEST
AFTERNOON BREEZINESS AND A NEAR PERSISTENCE TEMPERATURE FORECAST
WITH LOWER DESERT HIGHS COMMONLY REACHING THE MIDDLE TO UPPER 90S
AND NEAR 100F FOR SOME SPOTS.
A QUICK-MOVING, RELATIVELY LOW-AMPLITUDE TROUGH IS CURRENTLY SEEN
OFF THE PACIFIC NORTHWEST COAST. ENSEMBLES REMAIN IN EXCELLENT
AGREEMENT THAT THIS FEATURE WILL MOVE ONSHORE TONIGHT INTO EARLY
SATURDAY FOLLOWED BY A PERIOD OF AMPLIFICATION ONCE IT REACHES THE
INTERIOR WEST (APPROXIMATELY OVER THE GREAT BASIN). THERE WILL BE
A FEW SHORTWAVES THAT ROTATE THROUGH AS THE LARGER SYSTEM
DEEPENS, ONE LIKELY ON SATURDAY JUST AHEAD OF THE MORE PRONOUNCED
HEIGHT FALLS OVER THE GREAT BASIN, AND THE SECOND MORE POTENT
PIECE OF ENERGY LATE SUNDAY INTO MONDAY. HOWEVER, THERE ARE STILL
SOME NOTABLE DISCREPANCIES BETWEEN THE ENSEMBLES ON THE STRENGTH
OF THE TROUGH AND HOW CLOSE IT WILL DRAW TO THE AREA, AND SO THE
TIMING AND PEAK MAGNITUDE OF WINDS HAS CONTINUED TO SHIFT OVER THE
LAST FEW FORECAST UPDATES. FOR EXAMPLE, THE LATEST 00Z GEFS
FAVORS A DEEPER, MORE SOUTHERN SOLUTION FOR THIS SYSTEM THAN THE
ECMWF ENS OR GEPS, AND SO THERE IS MORE PRONOUNCED HEIGHT PACKING
OVER NORTHERN/CENTRAL AZ IN THE GEFS SOLUTIONS. THE RESULT OF SOME
OF THE LATEST GUIDANCE SHIFTS HAS BEEN A LATER TIMING OF PEAK
WINDS ALOFT (NOW SUNDAY NIGHT) AND THUS PEAK GUSTS ON SUNDAY
ACROSS THE AZ HIGH TERRAIN. ADDITIONALLY, AFTERNOON MINRHS HAVE
COME UP A FEW PERCENTAGE POINTS, LEADING TO MARGINAL AND SHORTER
DURATION OF CRITICAL (15% OR LESS) THRESHOLDS BEING MET.
REGARDLESS, BREEZY TO LOCALLY WINDY CONDITIONS WILL DEVELOP THIS
WEEKEND, LEADING TO WIDESPREAD ELEVATED AND LOCALLY NEAR CRITICAL
FIRE DANGER. A WIND ADVISORY WILL BE IN EFFECT FOR THE TYPICALLY
PRONE SW CORNER OF IMPERIAL COUNTY SATURDAY LATE AFTERNOON THROUGH
SUNDAY EVENING. FIRE WEATHER HEADLINES MAY BE POSTED LATER TODAY
FOR THE EASTERN AZ HIGH TERRAIN ON SUNDAY IF THE FORECAST HOLDS.
ASIDE FROM WINDS AND FIRE WEATHER CONCERNS, THE PATTERN THIS
WEEKEND WILL PROMOTE COOLER TEMPERATURES BY SUNDAY. LOWER LEVEL
THERMAL PROFILES WILL NOT HAVE HAD TIME TO MODIFY BY SATURDAY, AND
SO AFTERNOON HIGHS WILL BE SIMILAR, OR ONLY 1F-2F COOLER ACROSS
THE AREA. NEGATIVE H5 HEIGHT ANOMALIES AROUND THE 20TH-25TH
PERCENTILE OF CLIMATOLOGY WILL ESTABLISH OVER THE FORECAST AREA
SUNDAY INTO EARLY NEXT WEEK, WITH VALUES BOTTOMING OUT AROUND
571-574 DAM. AS A RESULT, ANTICIPATE LOWER DESERT HIGHS TO FALL
INTO A 90F-95F RANGE BY SUNDAY.
LONG TERM /MONDAY THROUGH THURSDAY/
THE AFOREMENTIONED SECOND, MORE POTENT PIECE OF ENERGY WILL
ROTATE THROUGH JUST NORTH OF THE AREA SUNDAY NIGHT INTO MONDAY,
WITH SEVERAL GLOBAL MODELS DEPICTING AN ASSOCIATED FRONT BEING
SENT DOWN THE LOWER CO RIVER VALLEY, RESULTING IN LOCALLY WINDY
CONDITIONS FOR PORTIONS OF SOUTHEAST CA MONDAY MORNING. THIS IS
THE FINAL ANTICIPATED IMPACT FROM THE SYSTEM THAT DEEPENS OVER THE
WESTERN US THIS WEEKEND, AS NEGATIVE HEIGHT ANOMALIES RETREAT TO
THE NORTH AND EAST HEADING INTO THE MIDDLE OF THE UPCOMING
WORKWEEK. MONDAY IS ALSO SHAPING UP TO BE THE "COOLEST" OF THE
NEXT 7 DAYS, WITH AFTERNOON HIGHS POTENTIALLY STRUGGLING TO REACH
90F ACROSS THE LOWER DESERTS, AROUND 5F BELOW DAILY NORMALS.
FORECAST UNCERTAINTY REMAINS MODERATE TO HIGH MONDAY ONWARD,
HOWEVER, AS THE CORE OF THE WEEKEND SYSTEM DEPARTS NORTHEASTWARD,
SOME MEASURE OF BROAD CYCLONIC FLOW OVER THE WESTERN US WILL
REMAIN AND LIKELY EVOLVE INTO QUASI-ZONAL FLOW THROUGH THE MIDDLE
OF THE WEEK. HEIGHTS ALOFT WILL REBOUND CLOSER TO SEASONAL
AVERAGES AND SO TEMPERATURES ARE EXPECTED TO WARM THROUGH THE
MIDDLE OF THE WEEK, WITH DRY CONDITIONS CONTINUING.
AVIATION
UPDATED AT 1141Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
TYPICAL DIURNAL WIND PATTERNS ARE FAVORED THROUGH THE TAF PERIOD,
WITH SPEEDS MOSTLY STAYING BELOW 10 KTS, UNDER CLEAR SKIES. A
PERIOD OF LIGHT SOUTHERLY CROSS-RUNWAY WINDS ARE ANTICIPATED AT
KPHX AROUND MIDDAY AHEAD OF THE WESTERLY SHIFT THIS AFTERNOON.
OCCASIONAL AFTERNOON/EARLY EVENING GUSTS IN THE MID TO UPPER TEENS
WILL BE COMMON.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO MAJOR AVIATION WEATHER CONCERNS UNDER CLEAR SKIES CAN BE
EXPECTED THROUGHOUT THE TAF PERIOD. AT KIPL, WESTERLY WINDS WILL
BE COMMON WHILE AT KBLH, WINDS WILL FLUCTUATE PREDOMINANTLY
BETWEEN THE SOUTH TO SOUTHWEST. GUSTS UPWARDS OF 25 KTS ARE
ANTICIPATED ONCE AGAIN LATE FRIDAY AFTERNOON/EARLY EVENING AT
KIPL.
FIRE WEATHER
SLIGHTLY ABOVE NORMAL TEMPERATURES AND GENERALLY LIGHT WINDS WITH
TYPICAL AFTERNOON UPSLOPE/UPVALLEY BREEZINESS WILL PREVAIL TODAY.
A WEATHER SYSTEM WILL MOVE ONSHORE ALONG THE PACIFIC NORTHWEST
EARLY SATURDAY AND DEEPEN OVER THE WESTERN US RESULTING IN
INCREASED WINDS ACROSS THE AREA THIS WEEKEND. AFTERNOON/EARLY
EVENING WIND GUSTS WILL COMMONLY PEAK BETWEEN 20-35 MPH
SATURDAY, WITH LOCALLY STRONGER GUSTS IN SOUTHEAST CA. THE
STRONGEST GUSTS BY SUNDAY WILL LIKELY BE CONFINED TO EASTERN AZ
HIGHER TERRAIN. THIS WILL LIKELY RESULT IN ELEVATED TO LOCALLY
CRITICAL FIRE WEATHER CONDITIONS ACROSS THE REGION BOTH DAYS.
AFTERNOON MINRHS MOSTLY BETWEEN 8-12% TODAY WILL INCREASE BY
SEVERAL POINTS THIS WEEKEND, WITH VALUES 7-15% AREAWIDE SATURDAY,
THEN 10-20% SUNDAY. OVERNIGHT RECOVERIES RANGING FROM 25-45%
ACROSS THE AREA AND IMPROVING ONLY SLIGHTLY FROM THERE ON SATURDAY
AND SUNDAY NIGHTS.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...WIND ADVISORY FROM 2 PM SATURDAY TO 11 PM PDT SUNDAY FOR CAZ562.
WIND ADVISORY FROM 4 PM TO 11 PM PDT SATURDAY FOR CAZ566.
SHORT TERM...WHITTOCK
LONG TERM...WHITTOCK
AVIATION...BENEDICT/LOJERO
FIRE WEATHER...WHITTOCK
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