877
FXUS65 KPSR 150908
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
208 AM MST THU JAN 15 2026
KEY MESSAGES
- DRY CONDITIONS WITH TEMPERATURES HOVERING AROUND 8 TO 12 DEGREES
ABOVE NORMAL WILL PREVAIL THROUGH THIS WEEKEND.
- A SLIGHT COOLING TREND IS ANTICIPATED BY EARLY NEXT WEEK WITH
LOWER DESERT HIGHS FALLING FROM THE UPPER 70S TO THE MID 70S
SHORT TERM /TODAY THROUGH SATURDAY/
AN UNSEASONABLY STRONG RIDGE OF HIGH PRESSURE LOCATED OVER NORTHERN
CA HAS REMAIN INTACT AND UNCHANGED OVER THE PAST 24 HOURS. THIS
LARGE SCALE RIDGING PATTERN CONTINUES TO RESULT IN POSITIVE HGHT
ANOMALIES OVERSPREADING THE DESERT SOUTHWEST WITH H5 HGHTS NOW UP TO
582-584 DAM WHICH HAVE EXCEEDED THE 90TH PERCENT OF CLIMATOLOGY FOR
THIS TIME OF YEAR. THE NBM DETERMINISTIC HAS BEEN PERFORMING
POORLY W.R.T TEMPERATURES OVER THE PAST COUPLE DAYS AS OBSERVED
HIGHS HAVE BEEN 3 TO 5 DEGREES COOLER THAN FORECAST. THIS
DISCREPANCY IS LIKELY DUE TO THE FACT THERE HAS BEEN A PERSISTENT
NE DOWNSLOPING WIND COMPONENT WHICH HAS LEAD TO COMPRESSIONAL
WARMING ACROSS THE FOOTHILLS AND LOWER DESERTS. THIS MAY BE THE
CASE AGAIN TODAY AS BREEZY NE WINDS ARE ANTICIPATED THROUGH AT
LEAST EARLY THIS AFTERNOON. THEREFORE, FORECAST HIGHS WERE
ADJUSTED UPWARD TO BE MORE IN LINE WITH THE NBM 75TH PERCENTILE.
HIGHS ARE EXPECTED TO AGAIN REACH THE UPPER 70S IN MOST LOWER
DESERT COMMUNITIES THIS AFTERNOON, ALTHOUGH A FEW LOCATIONS
INCLUDING YUMA AND EL CENTRO COULD SEE HIGHS REACH THE LOW 80S.
HEADING INTO THIS WEEKEND, LONGWAVE TROUGHING OVER THE CENTRAL CONUS
WILL RETROGRADE SLIGHTLY AS A RESULT OF JET ENERGY DIGGING INTO
THE TROUGH BASE DOWNSTREAM. THIS WILL CAUSE THE RIDGE AXIS TO
SLIDE FARTHER NW AND ALLOW HEIGHTS ALOFT OVER OUR FORECAST AREA TO
DECREASE SLIGHTLY FRIDAY AND SATURDAY. DESPITE THE SLIGHT
REDUCTION IN 500 MB HEIGHTS, THERE WILL NOT BE A NOTICEABLE
DECREASE IN SFC TEMPERATURES AS HIGHS REMAIN IN THE MID TO UPPER
70S ACROSS THE LOWER DESERTS OR AROUND 6 TO 8 DEGREES ABOVE NORMAL.
LONG TERM /SUNDAY THROUGH THURSDAY/
LONG RANGE DETERMINISTIC GUIDANCE AND ENSEMBLE MEMBERS REMAIN IN
GOOD AGREEMENT THAT THE WEST COAST RIDGING AND CENTRAL U.S.
TROUGHING WILL CONTINUE THROUGH AT LEAST THE FIRST HALF OF NEXT
WEEK. THERE ARE SOME SIGNALS WITHIN THE EPS AND GEFS CLUSTERS THAT
THE RIDGE MAY BEGIN TO BREAK DOWN BY THE END OF NEXT WEEK. UNTIL
THEN, THERE IS STILL HIGH CONFIDENCE THAT DAILY TEMPERATURES WILL
HOVER WELL ABOVE NORMAL (6-10 DEGREES). BY THE MONDAY-TUESDAY
TIMEFRAME, OUR FORECAST AREA MAY SEE A SLIGHT COOLING TREND DUE TO
THE RELAXATION OF 500 MB HEIGHTS AS LOWER DESERT HIGHS FALL INTO
THE LOW TO MID 70S. WITH PERSIST NW FLOW CARRYING INTO EARLY NEXT
WEEK, DRY CONDITIONS ARE EXPECTED TO CONTINUE WITH RAIN CHANCES
REMAINING NIL ACROSS THE DESERT SOUTHWEST.
AVIATION
UPDATED AT 0500Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT; AND
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO MAJOR AVIATION WEATHER CONCERNS WILL EXIST THROUGH THURSDAY
UNDER PERIODS OF PASSING HIGH CIRRUS DECKS. EASTERLY WINDS WILL BE
FAVORED FOR THE PHOENIX TERMINALS THROUGH MOST OF THE PERIOD WITH
SOME VARIABILITY NEAR SUNSET THURSDAY AS DIRECTIONS ATTEMPT TO
SWITCH W/NW. A PERIOD OF LIGHT SW'RLY WINDS MAY ALSO DEVELOP AT
KPHX DURING THE PRE-DAWN HOURS THURSDAY, BUT CONFIDENCE IN THIS
OCCURRING IS LOW. A N/NW WIND COMPONENT WILL PREVAIL ACROSS SE
CALIFORNIA DURING THE DAYTIME HOURS AND BACK TO MORE OF A W/NW
DURING THE OVERNIGHT HOURS. EXTENDED PERIODS OF NEARLY CALM
CONDITIONS WILL BE COMMON ACROSS THE ENTIRE REGION, ESPECIALLY
OVERNIGHT AND IN THE MORNING.
FIRE WEATHER
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL OVER THE NEXT SEVERAL
DAYS WITH DRY WEATHER AND MOSTLY SUNNY SKIES PREVAILING. MINRH
VALUES OF 15-30% AND OVERNIGHT RECOVERIES OF 40-70% WILL CONTINUE
THROUGH THE END OF THE WORKWEEK. BY THIS WEEKEND, DRIER AIR WILL
FILTER INTO THE AREA CAUSING MINRHS TO FALL AROUND 15-25% ALONG WITH
OVERNIGHT RECOVERIES OF 30-60%. ELEVATED EASTERLY FLOW WILL CONTINUE
ACROSS THE EASTERN DISTRICTS TODAY AND TO A LESSER EXTENT ON FRIDAY.
GUSTS UP TO 20-25 MPH WILL BE POSSIBLE AT TIMES. WINDS SHOULD RELAX
THIS WEEKEND AND FOLLOW TYPICAL DIURNAL PATTERNS.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM...SALERNO
LONG TERM...SALERNO
AVIATION...BENEDICT/18
FIRE WEATHER...SALERNO
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