675
FXUS65 KPSR 281205
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
505 AM MST FRI MAR 28 2025
UPDATE
UPDATED 12Z AVIATION DISCUSSION.
SYNOPSIS
A QUICK MOVING DRY WEATHER SYSTEM WILL BRING BREEZY TO LOCALLY
WINDY CONDITIONS AND SLIGHTLY COOLER TEMPERATURES TO THE REGION
TODAY. AFTER THIS INITIAL WEATHER SYSTEM DEPARTS, THE REGION WILL
REMAIN UNDER THE INFLUENCE OF ZONAL FLOW ALOFT OR WEAK TROUGHING
INTO EARLY NEXT WEEK. THIS PATTERN WILL FOSTER CONTINUED BREEZY
CONDITIONS AND TEMPERATURES HOVERING AROUND NORMAL. BY THE END OF
NEXT WEEK, A POTENTIAL STRONGER WEATHER SYSTEM COULD BRING BELOW
NORMAL TEMPERATURES AND CHANCES FOR SHOWERS TO THE REGION.
DISCUSSION
AFTER A STRETCH OF WELL ABOVE AVERAGE TEMPERATURES, WE WILL
FINALLY SEE A REPRIEVE FROM THE EARLY SPRING HEAT AS A SERIES OF
QUICK MOVING WEATHER SYSTEMS BRINGS MORE SEASONAL TEMPERATURES TO
THE FORECAST AREA. TODAY, THE FIRST IN THE SERIES OF DRY WEATHER
SYSTEMS WILL ARRIVE. THIS SYSTEM WILL DRAG A PACIFIC COLD FRONT
THROUGH SOUTHCENTRAL AZ BY THIS AFTERNOON RESULTING IN AN UPTICK
IN WINDS AND TEMPERATURES COOLING CLOSER TO AVERAGE. DESPITE A
LACK OF MOISTURE WITH THIS SYSTEM, FORECAST SOUNDINGS DO SHOW
SATURATION ABOVE 15 KFT WHICH WILL EQUATE TO SOME MID-LVL CLOUDS
AND POSSIBLY SOME VIRGA SHOWERS/SPRINKLES PROGRESSING THROUGH THE
LOWER DESERTS. WIDESPREAD BREEZY CONDITIONS ARE EXPECTED IN THE
WAKE OF THE FRONT WITH GUSTS INCREASING TO AROUND 20-30 MPH. WINDS
WILL BE STRONGEST ACROSS THE IMPERIAL VALLEY WHERE GUSTS COULD
REACH 30-40 MPH AT TIMES AND EVEN HIGHER UP TO 50 MPH IN SW
IMPERIAL COUNTY INCLUDING THE MOUNTAIN SPRINGS AREA. THEREFORE, A
WIND ADVISORY WILL REMAIN IN EFFECT FOR THE FAR SW CORNER OF
IMPERIAL COUNTY THROUGH LATE TONIGHT. HIGHS THIS AFTERNOON WILL
TOP OUT IN THE LOWER TO MID 80S ACROSS THE LOWER DESERTS AND MID
70S IN THE HIGH TERRAIN LOCATIONS.
HEADING INTO THIS WEEKEND, WESTERLY ZONAL FLOW WILL SET UP OVER THE
FORECAST REGION WHICH WILL KEEP HIGHS RIGHT AROUND AVERAGE IN THE
UPPER 70S TO LOWER 80S ACROSS THE LOWER DESERTS. THE 700-500 MB HGHT
GRADIENT WILL CONTINUE TO BE TIGHT RESULTING IN BREEZY CONDITIONS,
ESPECIALLY ACROSS SE CALIFORNIA AND THE AZ HIGH TERRAIN EACH
AFTERNOON/EVENING. THERE WILL ALSO BE BATCHES OF HIGH CLOUDS THAT
STREAM IN FROM THE EASTERN PACIFIC THROUGH SUNDAY, BUT OUR REGION IS
EXPECTED TO REMAIN DRY. BY EARLY NEXT WEEK, 850 MB TEMPERATURES WILL
CLIMB TO AROUND 14-15C ON MONDAY WHICH LOOKS TO BE THE WARMEST DAY
OF THE FORECAST PERIOD. FROM TUESDAY ONWARDS, LONGWAVE TROUGHING
WILL TAKE SHAPE OVER THE WESTERN CONUS AND WILL INTRODUCE NEGATIVE
HGHT ANOMALIES OVER THE FORECAST AREA. THEREFORE, TEMPERATURES WILL
COOL DOWN CLOSER TO AVERAGE THROUGH THE MIDDLE OF THE WEEK.
ENSEMBLE GUIDANCE DOES SHOW OVERALL TROUGHING PERSISTING INTO THE
LATTER HALF OF NEXT WEEK. HOWEVER THERE ARE LARGE DISCREPANCIES IN
BOTH THE STRENGTH AND POSITIONING OF THE OVERALL TROUGH. THE EPS
IS MORE BULLISH SHOWING A DEEPER AND STRONGER CLOSED LOW ARRIVING
INTO THE DESERT SOUTHWEST DURING THE THURSDAY-FRIDAY TIMEFRAME. IF
THIS SOLUTION PLAYS OUT, WE WILL HAVE A BETTER OPPORTUNITY FOR
INCREASING MOISTURE AND RAIN CHANCES. CURRENTLY THE NBM HAS AROUND
20-30 POPS ACROSS SOUTHCENTRAL AZ BEGINNING LATE THURSDAY AND
PERSISTING INTO FRIDAY. HOWEVER, THERE IS STILL A LOT OF
UNCERTAINTY REGARDING THIS SYSTEM AS IT IS STILL 6-7 DAYS OUT.
WHAT DOES LOOK MORE LIKELY IS TEMPERATURES REMAINING NEAR AVERAGE
THROUGH THE END OF NEXT WEEK.
AVIATION
UPDATED AT 1200Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NO MAJOR WEATHER CONCERNS WILL EXIST THROUGH EARLY SATURDAY
MORNING UNDER THICKENING MID-LEVEL CIGS THIS AFTERNOON. WINDS HAVE
SHIFTED TO AN EASTERLY COMPONENT ACROSS THE TERMINALS, AND THIS
EAST COMPONENT SHOULD PERSIST THROUGH AT LEAST 15-16Z. CONFIDENCE
IS LOW TO MODERATE ON THE EXACT TIMING OF A WEST SHIFT, HOWEVER,
WINDS SHOULD SHIFT OUT OF THE WEST EARLIER THAN USUAL AND INCREASE
IN SPEED BY LATE THIS MORNING. THIS AFTERNOON, MOST GUIDANCE SHOWS
THE POTENTIAL FOR OCCASIONAL SOUTHWESTERLY GUSTS TO AROUND 20 KTS,
BUT WITH THE INFLUENCE OF THICK CLOUD COVER, SPEEDS ARE EXPECTED
TO PREVAIL AOB 12 KTS SUSTAINED. PERIODS OF VIRGA SHOULD BE COMMON
ACROSS THE AREA THIS AFTERNOON.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
GUSTY WEST TO SOUTHWEST WINDS WILL BE THE PRIMARY AVIATION CONCERN
THROUGH THE TAF PERIOD UNDER BKN-OVC MID-LEVEL CLOUD DECKS THIS
MORNING. AT KIPL, GUSTS TO AROUND 20-25 KTS WILL BE COMMON THROUGH
THIS EVENING, WITH SOME PERIODS OF LIGHTER SPEEDS EARLY THIS
MORNING AND STRONGER GUSTS BY LATE THIS AFTERNOON INTO THIS
EVENING. WINDS WILL REMAIN OUT OF THE WEST THROUGH THE PERIOD AT
KIPL. AT KBLH, SPEEDS WILL BE LIGHTER, WITH OCCASIONAL GUSTS TO
AROUND 20 KTS THIS AFTERNOON INTO THE EVENING AND DIRECTIONS
VARYING FROM SSW TO WSW. EXPECT MID-LEVEL CIGS TO CLEAR
TEMPORARILY THIS AFTERNOON AND RETURN TONIGHT INTO EARLY SATURDAY
MORNING.
FIRE WEATHER
CONTINUED DRY AND BREEZY CONDITIONS ARE EXPECTED TO PERSIST
THROUGH THIS WEEKEND, RESULTING IN PERIODS OF ELEVATED FIRE
WEATHER. THE STRONGEST WINDS UP TO 25-35 MPH WILL RESIDE ACROSS
THE WESTERN DISTRICTS AND HIGHER TERRAIN OF MARICOPA AND GILA
COUNTIES. MINIMUM RELATIVE HUMIDITY IS EXPECTED TO RANGE FROM
15-20% EACH AFTERNOON AND OVERNIGHT RECOVERIES SHOULD REMAIN FAIR
UP TO 40-50%. THERE WILL BE A SLOW IMPROVEMENT IN MOISTURE LEVELS
BY THE MIDDLE TO LATTER PORTIONS OF NEXT WEEK AS A POTENTIAL
STRONGER WEATHER SYSTEM ARRIVES. THERE IS STILL A LOT OF
UNCERTAINTY WHETHER ANY MEANINGFUL PRECIPITATION WILL ACCOMPANY
THIS SYSTEM, BUT CHANCES FOR ANY WETTING RAINFALL LOOKS LOW AT
THIS TIME.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...WIND ADVISORY UNTIL 5 AM PDT SATURDAY FOR CAZ562.
DISCUSSION...SALERNO
AVIATION...WHITTOCK/18
FIRE WEATHER...SALERNO
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