579
FXUS65 KPSR 292301
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
400 PM MST SAT MAR 29 2025
UPDATE
UPDATED AVIATION
SYNOPSIS
TEMPERATURES WILL REMAIN AROUND NORMAL THROUGH EARLY NEXT WEEK WITH
HIGHS REMAINING IN THE LOW TO MID EIGHTIES ACROSS THE LOWER DESERTS.
AFTERNOON BREEZINESS CAN BE EXPECTED EACH DAY WITH THE STRONGEST
GUSTS RESIDING ACROSS SOUTHEAST CALIFORNIA. A PATTERN CHANGE NEXT
WEEK WILL BRING CONTINUED BREEZINESS, WITH THE STRONGEST WINDS
TUESDAY, MUCH COOLER TEMPERATURES, AND A LOW CHANCE FOR RAIN LATE IN
THE WEEK.
DISCUSSION
SKIES HAVE CLEARED UP FOLLOWING THE PASSAGE OF A WEAK SHORTWAVE
TROUGH THIS MORNING, BUT SOME MORE THIN MID AND HIGH CLOUDS WILL
MOVE IN LATER THIS AFTERNOON THROUGH THIS EVENING AS A STREAM OF
UPPER LEVEL MOISTURE MOVES IN FROM THE WEST WITHIN THE QUASI-ZONAL
FLOW. OBJECTIVE ANALYSIS EARLY THIS AFTERNOON SHOWS 500MB HEIGHTS IN
THE REGION IN THE UPPER 560S DAM, WHICH IS AROUND THE 25TH
PERCENTILE FOR THIS TIME OF YEAR. GLOBAL MODELS KEEP THIS PATTERN
GOING THROUGH THIS WEEKEND. DESPITE THE NEGATIVE HEIGHT ANOMALIES,
SURFACE TEMPERATURES WILL HOVER RIGHT AROUND SEASONAL NORMS THROUGH
THIS WEEKEND, WITH LOWER DESERT HIGHS IN THE LOW 80S AND LOWS IN THE
MID TO UPPER 50S. AFTERNOONS AND EVENINGS WILL REMAIN BREEZY UNDER
THE THIS PATTERN. MOST LOWER DESERT LOCATIONS WILL SEE GUSTS UP TO
20-25 MPH, WHILE HIGHER TERRAIN EAST OF PHOENIX SEE GUSTS UP TO 25-
30 MPH. STRONGEST WINDS IN THE CWA WILL BE IN IMPERIAL COUNTY, WHERE
DOWNSLOPING ENHANCEMENTS WILL PUSH GUSTS UP TO 35 MPH AND WIND GUSTS
IN THE SOUTHWEST CORNER OF THE COUNTY MAY GUST UP TO 50 MPH. A WIND
ADVISORY HAS BEEN ISSUED FOR THE SOUTHWEST CORNER FOR THIS EVENING
THROUGH SUNDAY MORNING. THIS MAY BE A COMMON ISSUANCE AS THE PATTERN
PERSISTS THROUGH EARLY NEXT WEEK.
A PATTERN SHIFT IS STILL EXPECTED BY THE MIDDLE OF NEXT WEEK WITH
GREATER NEGATIVE HEIGHT ANOMALIES ACROSS THE WESTERN CONUS AS
LONGWAVE TROUGHING DEVELOPS, WITH MULTIPLE EMBEDDED SHORTWAVE
TROUGHS. GLOBAL ENSEMBLES ARE NOW IN MUCH BETTER AGREEMENT WITH THIS
PATTERN THAN THEY HAVE BEEN THE PAST FEW DAYS. MOST NOTABLY THIS
PATTERN, WHICH WILL PERSIST THROUGH THE END OF NEXT WEEK, WILL DROP
TEMPERATURES 5-10 DEGREES BELOW NORMAL, MEANING LOWER DESERT HIGH
TEMPERATURES IN THE MIDDLE 70S, AND CONTINUE THE BREEZY CONDITIONS.
UNFORTUNATELY, THE PROSPECT FOR RAIN IS NOT GREAT WITH THIS LONGWAVE
PATTERN NEXT WEEK. AT LEAST NOT FOR THE LOWER DESERTS, DUE LARGELY
TO THE MORE CONTINENTAL TRACK OF THE TROUGH AND SEASONAL TO SUB-
SEASONAL MOISTURE LEVELS. LATEST NBM POPS HAVE DROPPED SIGNIFICANTLY
DURING THE SECOND HALF OF NEXT WEEK. POPS NOW MAX OUT AT 10% IN THE
LOWER DESERTS OF SOUTH-CENTRAL AZ ON FRIDAY, WITH SLIGHTLY HIGH POPS
IN THE HIGHER TERRAIN. MEDIAN TOTAL QPF FROM GLOBAL ENSEMBLES IS NO
MEASURABLE RAIN FOR LOWER DESERTS AND THE 90TH PERCENTILE (10%
CHANCE) IS ONLY AROUND 0.1-0.2". THIS DOES NOT MEAN THERE WILL NOT
BE ANY RAIN SHOWERS AROUND, BUT DO NOT COUNT ON ANY MEANINGFUL RAIN
WITH THIS SYSTEM.
WINDS LOOK LIKE THE BIGGEST SENSIBLE WEATHER IMPACT WITH THIS
PATTERN CHANGE, ESPECIALLY TUESDAY. STRONG PRESSURE PACKING AND
700MB WINDS UP TO 40-50 KTS TUESDAY, AS THE LONGWAVE TROUGH DROPS
DOWN INTO THE AREA, WILL LEAD TO WIDESPREAD BREEZY TO WINDY
CONDITIONS. LATEST NBM GUIDANCE WIND GUSTS SHOWS WIDESPREAD SURFACE
WIND GUSTS UP TO 30-40 MPH. HOWEVER, THIS MAY TREND UPWARD AS THE
NBM IS KNOWN TO UNDERPLAY THE WINDS SLIGHTLY. IN ADDITION TO THE
WINDS, THERE WILL BE POTENTIAL FOR BLOWING AND LOFTED DUST.
AVIATION
UPDATED AT 2300Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
OCCASIONAL LATE AFTERNOON/EARLY EVENING GUSTY WINDS WILL BE THE MAIN
WEATHER ISSUE THROUGH SUNDAY EVENING UNDER PERIODS OF PASSING HIGH
CIRRUS DECKS. CONFIDENCE IS VERY GOOD THAT GUSTS AROUND 20KT WILL BE
COMMON THROUGH EARLY/MID EVENING BEFORE DECOUPLING. SIMILAR TO THE
PAST COUPLE DAYS, THE OVERNIGHT SWITCH TO AN EASTERLY COMPONENT WILL
OCCUR SLIGHTLY LATER THAN USUAL, THEN REVERTING BACK TO WESTERLY
SUNDAY LATE MORNING/EARLY AFTERNOON SOMEWHAT EARLIER THAN USUAL.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
PERIODS OF GUSTY WINDS WILL BE THE PRIMARY WEATHER ISSUE THROUGH
SUNDAY EVENING UNDER PASSING HIGH CIRRUS DECKS. CONFIDENCE IS GOOD
THAT WESTERLY GUSTS AROUND 25KT WILL IMPACT KIPL THROUGH THE EVENING
BEFORE DECOUPLING LATE NIGHT. GUSTS SHOULD RESUME LATE SUNDAY
AFTERNOON. LESS GUSTINESS WILL OCCUR AT KBLH WITH MORE VARIABILITY
IN DIRECTIONS, PARTICULARLY LATE NIGHT/EARLY MORNING, HOWEVER
DIRECTIONS SHOULD GENERALLY VARY BETWEEN WESTERLY AND SOUTHERLY
THROUGH THE PERIOD.
FIRE WEATHER
SEASONAL TEMPERATURES, DRY CONDITIONS, AND AFTERNOON BREEZINESS ARE
EXPECTED TO PERSIST THROUGH EARLY NEXT WEEK. EACH DAY DOES LOOK TO
BE PROGRESSIVELY WINDIER FROM SUNDAY-TUESDAY. THE STRONGEST WINDS
WILL RESIDE ACROSS THE WESTERN DISTRICTS AND HIGHER TERRAIN OF
MARICOPA AND GILA COUNTIES WHERE ELEVATED FIRE WEATHER CONCERNS WILL
REMAIN HEIGHTENED. WINDIEST DAY, AND HIGHEST FIRE WEATHER CONCERN,
IN THE FORECAST IS TUESDAY. MINIMUM RELATIVE HUMIDITY IS EXPECTED TO
RANGE FROM 15-20% MOST AFTERNOONS, INCLUDING TUESDAY, AND OVERNIGHT
RECOVERIES WILL BE FAIR AROUND 40-60%. A PATTERN CHANGE NEXT WEEK
WILL BRING BELOW NORMAL TEMPERATURES AND A LOW CHANCE (10-20%) FOR
SOME SHOWERS, MAINLY LATE WEEK, BUT CWR IS CURRENTLY AROUND 0-5%.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...WIND ADVISORY UNTIL 11 AM PDT SUNDAY FOR CAZ562.
DISCUSSION...BENEDICT
AVIATION...18
FIRE WEATHER...BENEDICT/SALERNO
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