559
FXUS65 KPSR 180908
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
208 AM MST SUN JAN 18 2026
KEY MESSAGES
- STRONG HIGH PRESSURE ACROSS THE REGION WILL PERSIST FOR MUCH OF
THE COMING WEEK LEADING TO ABOVE NORMAL TEMPERATURES AND DRY
CONDITIONS.
- A BIT MORE UNSETTLED WEATHER MAY AFFECT THE REGION BY NEXT
WEEKEND WITH RAIN CHANCES POTENTIALLY RETURNING AND
TEMPERATURES DROPPING CLOSER TO NORMAL.
SHORT TERM /TODAY THROUGH TUESDAY/
TRANQUIL WEATHER CONDITIONS WILL PREVAIL EARLY THIS WEEK AS WE
REMAIN STUCK UNDER A BLOCKING RIDGE OF HIGH PRESSURE. THE CURRENT
WEATHER REGIME SHOWS AN OMEGA BLOCKING PATTERN WITH RIDGING
THROUGHOUT THE WESTERN U.S. AND SOUTHWEST CANADA AND DEEP
TROUGHING ACROSS THE EASTERN 2/3RDS OF THE CONUS AND CANADA. THIS
WILL CONTINUE TO PROVIDE FOR POSITIVE TEMPERATURES ANOMALIES
ACROSS THE DESERT SOUTHWEST AND MUCH OF THE WESTERN STATES THIS
WEEK. H5 HEIGHTS REACHING INTO THE 90TH PERCENTILE OF CLIMATOLOGY
WILL CONTINUE ACROSS OUR REGION TODAY BEFORE LOWERING ON MONDAY.
TEMPERATURES WILL BARELY RESPOND TO THE LOWERING HEIGHTS WITH
HIGHS ESSENTIALLY STAYING IN A 72-76 DEGREE RANGE EARLY THIS WEEK.
WE WILL ALSO BEGIN TO SEE SOME HIGH CLOUDS MOVE INTO THE AREA
LATER TODAY AND LAST THROUGH MONDAY, BUT THEY WILL REMAIN QUITE
THIN ALLOWING FOR PLENTY OF SUNSHINE BOTH DAYS. SUNNY SKIES ARE
EXPECTED FOR TUESDAY.
LONG TERM /WEDNESDAY THROUGH SATURDAY/
UPPER LEVEL RIDGING IS FORECAST TO CONTINUE ON WEDNESDAY AND
LIKELY INTO THURSDAY BEFORE MUCH OF THE WESTERN U.S. BEGINS TO
FALL UNDER SOME MODEST TROUGHING BY FRIDAY. AT THE SAME TIME, A
CUT-OFF LOW WILL DEVELOP OFF THE COAST OF CALIFORNIA WITH THE BULK
OF THE ENSEMBLE GUIDANCE POINTING AT THIS DISTURBANCE NOT GAINING
MUCH STRENGTH AND EVENTUALLY DRIFTING SOUTHEASTWARD BY NEXT
WEEKEND. THE SHIFT AWAY FROM THE RIDGING LATER THIS WEEK SHOULD
LOWER OUR TEMPERATURES MODESTLY BY FRIDAY INTO NEXT WEEKEND, BUT
SO FAR THE NBM KEEPS OUR TEMPERATURES BARELY TOUCHING THE NORMAL
RANGE. THE CUT-OFF LOW COULD GET CLOSE ENOUGH TO AFFECT PORTIONS
OF OUR REGION BY NEXT WEEKEND, BUT MODEL TRENDS HAVE BEEN LEANING
TOWARD THE SYSTEM MOSTLY BYPASSING OUR REGION TO THE SOUTH. MODELS
HAVE A DIFFICULT TIME HANDLING THESE CUT-OFF LOWS, SO FORECAST
CONFIDENCE REMAINS QUITE LOW FOR FRIDAY INTO NEXT WEEKEND. BETWEEN
THE GEFS AND THE EPS, AROUND 25% OF THE MEMBERS SHOW DECENT RAIN
CHANCES WITH THE CUT-OFF LOW. MODELS ARE NOT LIKELY TO HAVE A GOOD
HANDLE ON THIS SYSTEM UNTIL AT LEAST THE MIDDLE OF THE WEEK.
AVIATION
UPDATED AT 0522Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NO AVIATION CONCERNS ARE EXPECTED DURING THE TAF PERIOD. WINDS
WILL TEND TO FOLLOW THEIR DIURNAL TENDENCIES WITH SPEEDS GENERALLY
AOB 6 KT. EXTENDED PERIODS OF LIGHT AND VARIABLE TO CALM
CONDITIONS ARE ALSO EXPECTED. THE OVERALL SYNOPTIC PATTERN IS
CONDUCIVE TO KPHX SWITCHING TO LIGHT SW'RLY WINDS BRIEFLY IN THE
MORNING. HOWEVER, CONFIDENCE IN THIS SHIFT IS LOW, SO HAVE GONE
WITH VRB IN THE TAF FOR NOW. CLEAR SKIES WILL CONTINUE THROUGH
TOMORROW MORNING WITH FEW-SCT HIGH CIRRUS CLOUDS MOVING IN FOR THE
AFTERNOON AND EVENING HOURS.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
NO MAJOR AVIATION CONCERNS ARE EXPECTED OVER THE NEXT 24 HOURS.
CURRENT NW'RLY WINDS AT KBLH WILL GO W'RLY DURING THE OVERNIGHT
HOURS, THEN BACK NW'RLY TOMORROW AFTERNOON. AT KIPL, CURRENT W'RLY
WINDS WILL GO NW'RLY BY THE LATE MORNING HOURS. WIND SPEEDS AT
BOTH TERMINALS, WILL BE AOB 6 KT THROUGH THE TAF PERIOD. FEW-SCT
HIGH CIRRUS CLOUDS WILL CONTINUE THROUGH THE TAF PERIOD.
FIRE WEATHER
STRONG HIGH PRESSURE WILL PERSIST ACROSS THE REGION OVER THE NEXT
SEVERAL DAYS KEEPING TEMPERATURES ABOVE NORMAL AND DRY CONDITIONS
IN PLACE. DAILY MINRH VALUES WILL REMAIN STABLE, FALLING TO
15-20% EACH DAY WITH OVERNIGHT RECOVERIES OF 30-50%. WINDS WILL
OVERALL BE LIGHT THROUGH THE PERIOD WITH ONLY SOME PERIODIC
BREEZINESS ACROSS THE LOWER CO RIVER VALLEY AND OVER THE ARIZONA
HIGH TERRAIN.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM...KUHLMAN
LONG TERM...KUHLMAN
AVIATION...BERISLAVICH
FIRE WEATHER...KUHLMAN
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