771
FXUS65 KPSR 010455
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
955 PM MST FRI OCT 31 2025
UPDATE
UPDATED AVIATION DISCUSSION
KEY MESSAGES
- DRY AND TRANQUIL CONDITIONS WILL CONTINUE THROUGH NEXT WEEK WITH
TEMPERATURES REMAINING ABOVE NORMAL.
SHORT TERM /TODAY THROUGH SUNDAY/
AN INNOCUOUS SHORTWAVE DISTURBANCE IS PASSING SOUTHWARD ALONG THE CA
COAST EARLY THIS AFTERNOON, BRINGING SOME CIRRUS OVER THE AREA AND A
SLIGHT UPTICK IN WINDS MAINLY OVER THE EASTERN AZ HIGH TERRAIN. THE
MAIN STORY TODAY AND THROUGH THE WEEKEND, HOWEVER, WILL BE THE
PERSISTENT INFLUENCE OF HIGH PRESSURE OVER THE REGION. CURRENT 500
MB RAP ANALYSIS PLACES THE AXIS OF A HIGH AMPLITUDE RIDGE
APPROXIMATELY ALONG THE WEST COAST. ENSEMBLES SHOW THE RIDGE AXIS
SHIFTING EASTWARD OVER THE WEEKEND, WITH H5 HEIGHTS OVER THE
FORECAST AREA INCREASING FROM ~584 DAM THIS AFTERNOON TO A PEAK OF
AROUND 590 DAM LATE SATURDAY/EARLY SUNDAY AS THE RIDGE AXIS PASSES
DIRECTLY OVERHEAD. DESPITE THE INCREASING HEIGHTS ALOFT, THE
RELATIVELY SHORT RESIDENCE TIME OF THOSE PEAK VALUES WILL MEAN THAT
THERMAL PROFILES DO NOT HAVE MUCH TIME TO RESPOND, AND DAILY HIGHS
SHOULD BE FAIRLY STABLE IN A 5-8 DEGREE ABOVE NORMAL RANGE (IN
THE UPPER 80S TO AROUND 90F FOR THE TYPICALLY WARMER LOWER DESERT
LOCALES.)
LONG TERM /MONDAY THROUGH FRIDAY/
THE WEATHER PATTERN WILL REMAIN STAGNANT FOR OUR REGION WELL INTO
NEXT WEEK, POTENTIALLY LONGER. FORECAST H5 HEIGHTS ARE EXPECTED
TO MOSTLY RANGE BETWEEN 584-588DM, OR RIGHT AROUND THE 90TH
PERCENTILE OF CLIMATOLOGY, KEEPING TEMPERATURES ABOVE NORMAL.
ALTHOUGH THE RIDGE WILL REMAIN THE DOMINANT WEATHER FEATURE FOR
OUR REGION, THERE SHOULD BE A COUPLE OF DRY WEATHER SYSTEMS
PASSING THROUGH THE GREAT BASIN, ONE ON MONDAY AND ANOTHER DURING
THE MIDDLE OF NEXT WEEK. OTHER THAN SOME MOSTLY THIN HIGHER LEVEL
CLOUDS PASSING THROUGH OUR REGION, THESE SYSTEMS WILL LARGELY PASS
BY WITHOUT MUCH NOTICE. FORECAST TEMPERATURES FOR THE FIRST HALF
OF NEXT WEEK WILL REMAIN FAIRLY STABLE WITH HIGHS MOSTLY IN THE
UPPER 80S ACROSS THE LOWER DESERTS. GUIDANCE IS SUGGESTING A
SLIGHT COOL DOWN LATER NEXT WEEK WITH HIGHS FALLING BACK INTO THE
LOW TO MID 80S, BUT THAT SEEMS A LITTLE SUSPECT GIVEN FORECAST H5
HEIGHTS MAY ONLY DROP TO BETWEEN 582-585DM. EITHER WAY, THE
PATTERN WILL CONTINUE TO SUPPORT DRY WESTERLY FLOW THROUGH MOST
OF, IF NOT ALL OF NEXT WEEK.
AVIATION
UPDATED AT 0455Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT; AND
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO AVIATION WEATHER CONCERNS ARE EXPECTED DURING THE TAF PERIOD
UNDER CLEAR SKIES. WINDS WILL CONTINUE TO FOLLOW LIGHT AND DIURNAL
TENDENCIES WITH EXTENDED WINDOW OF VARIABLE TO EVEN CALM
CONDITIONS.
FIRE WEATHER
TEMPERATURES WILL FLUCTUATE A FEW DEGREES OVER THE NEXT 7 DAYS, BUT
REMAIN AROUND 5-8 DEGREES ABOVE NORMAL FOR THIS TIME OF YEAR. MINRHS
WILL BE AROUND 10-15% FOR THE LOWER DESERTS TO AROUND 20% FOR THE
HIGHER TERRAIN AREAS THROUGH THE WEEK, WITH OVERNIGHT RECOVERY OF 20-
40%. WINDS WILL FOLLOW THEIR TYPICAL DIURNAL TENDENCIES WITH MINIMAL
AFTERNOON GUSTINESS.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM...WHITTOCK
LONG TERM...KUHLMAN
AVIATION...RW
FIRE WEATHER...KUHLMAN
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