177
FXUS65 KPSR 212321
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
420 PM MST FRI FEB 21 2025
UPDATE
UPDATED AVIATION
SYNOPSIS
WARM, DRY, AND TRANQUIL WEATHER WILL PREVAIL THROUGH THIS WEEKEND
WITH TEMPERATURES CONTINUING TO RANGE AROUND 8 TO 10 DEGREES ABOVE
NORMAL. AN ANOMALOUSLY STRONG RIDGE OF HIGH PRESSURE IS THEN
EXPECTED TO BUILD OVER THE DESERT SOUTHWEST BEGINNING SUNDAY,
REACHING PEAK STRENGTH BY THE MIDDLE OF NEXT WEEK. THIS RIDGING
PATTERN WILL RESULT IN HIGHS APPROACHING THE LOWER 90S OR NEAR
RECORD TERRITORY ACROSS THE LOWER DESERT COMMUNITIES FROM TUESDAY
THROUGH THURSDAY.
DISCUSSION
CURRENT IR WV AND VISIBLE SATELLITE IMAGERY REVEALS A POSITIVELY
TILTED SHORTWAVE TROUGH APPROACHING THE 4-CORNERS REGION. AN
INCREASED PRESSURE GRADIENT IN RESPONSE TO THIS TROUGH HAS RESULTED
IN BREEZY TO LOCALLY WINDY CONDITIONS ACROSS THE COLORADO RIVER
VALLEY AND AZ HIGH TERRAIN THIS AFTERNOON WHERE GUSTS ARE NOW
REACHING 20-30 MPH. WINDS SHOULD BEGIN TO SLACKEN AFTER PEAK HEATING
WITH SPEEDS FALLING BELOW 10 MPH AFTER SUNSET. TEMPERATURES ACROSS
THE REGION WILL FALL INTO THE MID 40S TO LOWER 50S LATE TONIGHT.
BY THIS WEEKEND, DETERMINISTIC MODELS AND ENSEMBLE MEMBERS SHOW A
STEADY WARMING TREND AS A PATTERN SHIFT FROM NW FLOW ALOFT TO UPPER
LVL RIDGING TAKES SHAPE. ON SATURDAY, ANOTHER WEAK DISTURBANCE WILL
PROGRESS THROUGH THE AREA BUT WILL RESULT IN LITTLE TO NO CHANGE TO
OUR WEATHER CONDITIONS AS TEMPERATURES REMAIN AROUND 8 TO 10 DEGREES
ABOVE AVERAGE. RIDGING OVER THE EASTERN PACIFIC WILL THEN SHIFT EWD,
ENCOMPASSING MUCH OF THE DESERT SOUTHWEST ON SUNDAY. THIS WILL
RESULT IN HIGHS MAINLY REACHING INTO THE LOWER 80S ACROSS THE LOWER
DESERTS SUNDAY AFTERNOON.
H5 HEIGHTS WILL CONTINUE TO RISE ABOVE 580 DAM LATE SUNDAY INTO
MONDAY WHICH WILL PROMOTE A SIGNIFICANT WARM UP ACROSS THE ENTIRE
REGION EARLY NEXT WEEK. NBM FORECAST TEMPERATURES ARE STILL SHOWING
MID 80S MONDAY, AND MOSTLY THE UPPER 80S STARTING TUESDAY. A FEW
LOCATIONS ACROSS THE WESTERN DESERTS WILL LIKELY SEE THEIR FIRST 90
DEGREE READING OF THE YEAR ON TUESDAY AFTERNOON, WHICH WOULD BE
AROUND A MONTH EARLIER THAN NORMAL. THE MOST LIKELY TIMEFRAME FOR 90
DEGREE HIGHS IN SOUTHCENTRAL AZ INCLUDING THE PHOENIX METRO STILL
LOOKS TO BE WEDNESDAY-THURSDAY. DURING BOTH OF THESE DAYS, HIGHS
COULD REACH RECORD LEVELS AT PHOENIX SKY HARBOR (CURRENT CHANCES OF
REACHING RECORD HIGHS AT 40-60%).
PREVIOUS DISCUSSION
MODEL GUIDANCE IS STILL SHOWING A POTENTIAL SHIFT IN THE WEATHER
PATTERN LATE NEXT WEEK AS A PACIFIC LOW IS LIKELY TO DEVELOP AND
APPROACH THE WEST COAST AT SOME POINT BETWEEN NEXT THURSDAY AND
SATURDAY. TIMING AND TRACK DIFFERENCES AMONG THE ENSEMBLES MAKE IT
TOO DIFFICULT TO KNOW WHAT IS EXACTLY IN STORE FOR OUR REGION, BUT
GUIDANCE OVERALL FAVORS THE LOW TRACKING THROUGH OUR REGION AT SOME
POINT NEXT WEEKEND. FOR NOW, MOISTURE AVAILABILITY WITH THE SYSTEM
LOOKS TO BE FAIRLY LOW, SO ANY PROSPECTS FOR RAIN IS ALSO LOW. WE
SHOULD HOWEVER AT LEAST SEE A COOLING TREND BY NEXT WEEKEND, BUT SO
FAR NBM GUIDANCE INDICATES TEMPERATURES WILL REMAIN ABOVE NORMAL.
AVIATION
UPDATED AT 2320Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NO MAJOR WEATHER ISSUES WILL EXIST THROUGH SATURDAY EVENING UNDER A
FEW PASSING HIGH CIRRUS DECKS. CONFIDENCE IS VERY GOOD THAT WIND
CHARACTER WILL BE SIMILAR TO THE PAST 24 HOURS WITH THE EASTERLY
SHIFT MID/LATE EVENING.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
GUSTY NORTH WINDS THIS AFTERNOON AT KBLH WILL BE THE GREATEST
WEATHER IMPACT UNDER CLEAR SKIES. GUSTS 20-25 KTS WILL RELAX AFTER
SUNSET WITH WEAKER SPEEDS SATURDAY. NORTH WINDS SHOULD TEMPORARILY
BACK TO WESTERLY AT KIPL OVERNIGHT.
FIRE WEATHER
WARM AND DRY CONDITIONS WILL PERSIST THROUGH THE WEEKEND WITH STRONG
HIGH PRESSURE QUICKLY BUILDING INTO REGION BY SUNDAY. EXPECT BREEZY
CONDITIONS AGAIN THIS AFTERNOON ACROSS PORTIONS OF SOUTHEAST
CALIFORNIA INTO THE LOWER CO RIVER VALLEY BEFORE OVERALL LIGHT WINDS
ARE SEEN STARTING SATURDAY. LOW HUMIDITIES WILL CONTINUE DURING THE
PERIOD WITH MINRHS MAINLY BETWEEN 10-15% AND FAIR TO POOR OVERNIGHT
RECOVERIES TO AROUND 25-30%. UNSEASONABLY WARM TEMPERATURES ARE THEN
FORECAST FOR NEXT WEEK WHILE DRY CONDITIONS PERSIST.
CLIMATE
RECORD HIGH TEMPERATURES NEXT WEEK:
DATE PHOENIX YUMA EL CENTRO
---- ------- ---- ---------
FEB 24 91 IN 1904 93 IN 1986 92 IN 1986
FEB 25 92 IN 1921 95 IN 1986 94 IN 1986
FEB 26 91 IN 1986 96 IN 1986 95 IN 1986
FEB 27 92 IN 1986 95 IN 1986 96 IN 1986
FEB 28 89 IN 1986 97 IN 1986 92 IN 1986
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
DISCUSSION...SALERNO
PREVIOUS DISCUSSION...KUHLMAN
AVIATION...WHITTOCK/BENEDICT
FIRE WEATHER...KUHLMAN
CLIMATE...18
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