061
FXUS65 KPSR 121025
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
325 AM MST MON MAY 12 2025
SYNOPSIS
A DRY WEATHER SYSTEM WILL MOVE THROUGH THE REGION EARLY THIS WEEK
WHICH WILL ALLOW TEMPERATURES TO COOL THROUGH WEDNESDAY. IN ADDITION
TO COOLER TEMPERATURES THIS WEATHER SYSTEM WILL ALSO BRING BREEZY TO
LOCALLY WINDY CONDITIONS TO THE REGION OVER THE NEXT COUPLE OF DAYS.
THESE INCREASED WINDS IN COMBINATION WITH VERY LOW HUMIDITY WILL
LEAD TO ELEVATED FIRE WEATHER CONDITIONS. TEMPERATURES WILL RETURN
TO NEAR NORMAL LEVELS FOR THE SECOND HALF OF THE WEEK.
DISCUSSION
UPPER LEVEL WATER VAPOR SATELLITE IMAGERY AND OBJECTIVE ANALYSIS
DEPICT QUASI-ZONAL FLOW OVER ARIZONA WITH THE CENTER OF A LOW
PRESSURE SYSTEM JUST OFF THE COAST OF OREGON. THIS LOW WILL MOVE ON
SHORE THROUGHOUT THE MORNING AND CONTINUE TO PUSH EASTWARD INTO OUR
AREA OVER THE NEXT COUPLE OF DAYS. AS A RESULT TEMPERATURES WILL
COOL THROUGH THE MIDDLE OF THE WEEK. ALTHOUGH TEMPERATURES TODAY
WILL BE COOLER THAN THEY HAVE BEEN THE PAST COUPLE OF DAYS THEY WILL
STILL BE ABOVE NORMAL. WITH AFTERNOON HIGH TEMPERATURES IN THE
UPPER 90S TO LOW 100S ACROSS THE LOWER DESERTS AND IN THE 90S IN
THE HIGHER TERRAIN AREAS. THERE WILL STILL BE AREAS OF MODERATE
HEATRISK ACROSS PORTIONS OF SOUTH-CENTRAL AZ, SO MAKE SURE TO KEEP
PRACTICING SMART HEAT SAFETY. THE REAL COOL DOWN WILL BE FELT
TOMORROW WITH AFTERNOON HIGH TEMPERATURES FORECASTED TO BE 10-15
DEGREES COOLER THAN TODAY. THE BASE OF THE TROUGH WILL MOVE
THROUGH OUR FORECAST AREA DURING THE TUESDAY-WEDNESDAY TIMEFRAME,
WHICH WILL BE THE COOLEST DAYS OF THE WEEK WITH TEMPERATURES
FALLING BELOW NORMAL. AFTERNOON HIGH TEMPERATURES TUESDAY AND
WEDNESDAY ARE FORECASTED TO BE IN THE 80S TO NEAR 90 DEGREES
ACROSS THE LOWER DESERTS AND IN UPPER 70S TO MID 80S IN THE HIGHER
TERRAIN AREAS.
WHILE THIS WEATHER SYSTEM WILL MOVE THROUGH DRY, IT WILL CAUSE SOME
WEATHER IMPACTS. IT WILL BRING BREEZY TO LOCALLY WINDY CONDITIONS TO
THE REGION. WIND GUSTS OF 25-40 MPH ARE EXPECTED ACROSS THE AREA,
MAINLY DURING THE AFTERNOONS AND EVENING. THE HIGHEST WIND GUSTS
WILL OCCUR ACROSS SOUTHEASTERN CA AND THE HIGHER TERRAIN IN
EASTERN AZ. A WIND ADVISORY REMAINS IN EFFECT FOR THE FAR SW
CORNER OF IMPERIAL COUNTY FROM SUNRISE THIS MORNING THROUGH
SUNRISE WEDNESDAY MORNING WHERE WIND GUSTS UP TO 55 MPH WILL BE
POSSIBLE. HREF AND ECMWF SHOW GOOD CONFIDENCE (>70%) OF WINDS IN
EXCESS OF 40 MPH REACHING INTO IMPERIAL VALLEY. DUE TO THIS, THE
WIND ADVISORY HAS BEEN EXPANDED AND NOW INCLUDES THE REST OF
WESTERN IMPERIAL COUNTY (INCLUDING IMPERIAL VALLEY AND THE SALTON
SEA). THIS WIND ADVISORY IS IN EFFECT FROM THIS AFTERNOON THROUGH
THE EARLY MORNING HOURS ON WEDNESDAY FOR GUSTS UP TO 45 MPH. THESE
GUSTY WINDS IN COMBINATION WITH THE DRY CONDITIONS (RELATIVE
HUMIDITY OF 8-15%) AND DRY FUELS WILL LEAD TO ELEVATED FIRE
WEATHER CONDITIONS. DUE TO THIS COMBINATION A RED FLAG WARNING HAS
BEEN ISSUED FOR SOUTHERN GILA COUNTY AND THE HIGHER ELEVATIONS OF
NORTHEASTERN PINAL AND EASTERN MARICOPA COUNTIES FOR THIS
AFTERNOON AND EARLY EVENING AND AGAIN TOMORROW FROM THE LATE
MORNING THROUGH EARLY EVENING.
THE LOW PRESSURE SYSTEM WILL ADVECT INTO THE NORTHERN PLAINS DURING
THE LATTER HALF OF THE WEEK LEAVING QUASI-ZONAL FLOW IN ITS WAKE. H5
HEIGHTS WILL RISE OVER OUR AREA (TO A 576-579 DM RANGE) LEADING TO
SOME WARMING. THIS WILL ALLOW TEMPERATURES TO WARM BACK TO NEAR
NORMAL READINGS FOR THIS TIME OF YEAR WITH AFTERNOON HIGH
TEMPERATURES IN THE MID 90S ACROSS THE LOWER DESERTS AND IN THE 80S
IN THE HIGHER TERRAIN AREAS. THE QUASI-ZONAL FLOW WILL REMAIN
OVERHEAD HEADING INTO THE WEEKEND KEEPING TEMPERATURES STEADY FOR
THE END OF THE WEEK. GLOBAL ENSEMBLES START TO DIFFER BY THE END OF
THE FORECAST PERIOD, ALTHOUGH THEY HAVE COME INTO SLIGHTLY BETTER
AGREEMENT THAN YESTERDAY. OVERALL THE ENSEMBLES LEAN IN FAVOR
ANOTHER TROUGH MOVING INTO WESTERN CONUS BY THE END OF THE
WEEKEND. HOWEVER, THEY DIFFER ON THE EXACT STRENGTH AND TIMING OF
THIS TROUGH. WHETHER IT'S A STRONGER/DEEPER TROUGH OR
WEAKER/SHALLOWER TROUGH TEMPERATURES ARE EXPECTED TO COOL AT LEAST
A LITTLE BIT. DRY CONDITIONS WILL PERSIST THROUGH THE WEEKEND.
AVIATION
UPDATED AT 0530Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, KDVT:
NO AVIATION CONCERNS ARE ANTICIPATED THROUGH THE FORECAST PERIOD.
WINDS WILL REMAIN LIGHT, AOB 7 KTS OVERNIGHT WITH THE EXCEPTION OF
KIWA WHERE WINDS WILL BE SLIGHTLY MORE ELEVATED AROUND 11 KTS.
EXPECT AN EASTERLY SHIFT AT KPHX BY 09Z. WINDS WILL INCREASE OUT
OF THE S-SE AFTER SUNRISE TOMORROW MORNING, RESULTING IN A
SOUTHERLY CROSS-RUNWAY COMPONENT AT KPHX FOR APPROX 3-4 HOURS
BEFORE ULTIMATELY SHIFTING OUT OF THE SW BY THE EARLY AFTERNOON.
GUSTS BETWEEN 20-25 KTS WILL BE COMMON FROM THE LATE AFTERNOON
THROUGH THE EARLY EVENING AT ALL TERMINALS. HIGH CLOUDS WILL
CONTINUE TO OVERSPREAD THE REGION TONIGHT AND INTO TOMORROW WITH
BASES REMAINING AOA 15 KFT AGL.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
GUSTY WINDS AND THE POTENTIAL FOR BLOWING DUST WILL BE THE PRIMARY
AVIATION CONCERNS AT THE SOUTHEAST CA TERMINALS, ESPECIALLY BY
TOMORROW AFTERNOON AND EVENING. WINDS WILL REMAIN WESTERLY AT KIPL
AND SOUTHERLY TO SOUTHWESTERLY AT KBLH THROUGH THE PERIOD. EXPECT
SPEEDS TO BE ELEVATED AROUND 10-15 KTS OVERNIGHT. BY EARLY
TOMORROW MORNING, GUSTS WILL MATERIALIZE AT BOTH TERMINALS,
REACHING 25-30 KTS AT TIMES. STRONGER GUSTS INTO THE 30-35 KT
RANGE WILL BE POSSIBLE AT BOTH SITES BY TOMORROW AFTERNOON WHICH
COULD LEAD TO PERIODS OF REDUCED VSBY DUE TO BLOWING DUST. HIGH
CLOUDS WILL CONTINUE TO OVERSPREAD THE REGION WITH BASES REMAINING
AOA 18 KFT AGL.
FIRE WEATHER
ELEVATED FIRE DANGER WILL EXIST TODAY AND TOMORROW AS WARM
TEMPERATURES, LOW HUMIDITY LEVELS, AND GUSTY WINDS BECOME
JUXTAPOSED WITH RECEPTIVE, DRY FINE FUELS. MINRHS OF 8-15% WILL
BE COMMON THROUGHOUT THE WEEK FOLLOWING POOR TO FAIR OVERNIGHT
RECOVERY OF 20-50%. WINDS WILL BE STRONGEST TODAY AND TOMORROW
WITH GUSTS 25-40 MPH DURING THE AFTERNOON AND EARLY EVENING, SOME
HIGHER GUSTS ARE POSSIBLE IN WESTERN IMPERIAL COUNTY. GUSTS WILL
LIKELY BE MOST PRONOUNCED ACROSS RIDGE TOPS AND IN THE TYPICAL
DOWNSLOPING AREAS. SPEEDS SHOULD WEAKEN DURING THE LATTER HALF OF
THE WEEK, THOUGH STILL WILL RETAIN THE USUAL AFTERNOON UPSLOPE
GUSTINESS. TEMPERATURES WILL ALSO COOL DURING THE FIRST HALF OF
THE WEEK AS THE WEATHER SYSTEM MOVES INTO THE REGION, HOWEVER
SHOULD REBOUND CLOSER TO SEASONAL NORMALS BY THE END OF THE WEEK.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...RED FLAG WARNING FROM NOON TODAY TO 7 PM MST THIS EVENING FOR
AZZ133.
RED FLAG WARNING FROM 10 AM TO 8 PM MST TUESDAY FOR AZZ133.
CA...WIND ADVISORY FROM 5 AM EARLY THIS MORNING TO 5 AM PDT WEDNESDAY
FOR CAZ562.
WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 2 AM PDT WEDNESDAY FOR
CAZ563-566-567.
DISCUSSION...BERISLAVICH
AVIATION...SALERNO
FIRE WEATHER...BERISLAVICH/18
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