631
FXUS65 KPSR 100923
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
223 AM MST TUE FEB 10 2026
KEY MESSAGES
- WELL ABOVE NORMAL TEMPERATURES CONTINUE TODAY WITH HIGHS IN THE
UPPER SEVENTIES TO LOWER EIGHTIES, RESULTING IN AREAS OF MINOR
HEATRISK ACROSS THE LOWER ELEVATIONS.
- A PATTERN CHANGE MID TO LATE WEEK WILL LEAD TO COOLER
TEMPERATURES AND INCREASING RAIN CHANCES, PARTICULARLY ACROSS
THE EASTERN HALF OF ARIZONA ON FRIDAY.
- WEATHER CONDITIONS WILL BRIEFLY TURN QUIETER OVER THE WEEKEND
BEFORE BECOMING MORE UNSETTLED ONCE AGAIN EARLY NEXT WEEK AS
ANOTHER STORM SYSTEM IMPACTS THE REGION, RESULTING IN BETTER
CHANCES OF MORE WIDESPREAD PRECIPITATION.
SHORT TERM /TODAY THROUGH WEDNESDAY/
LATEST SATELLITE IMAGERY SHOWS A STREAM MID TO HIGH-LEVEL CLOUDINESS
MOVING ONSHORE ACROSS CENTRAL AND SOUTHERN CA AND THROUGH THE GREAT
BASIN IN RESPONSE TO A LONGWAVE TROUGH GRADUALLY ENCROACHING UPON
THE WEST COAST. THE APPROACHING TROUGH IS THE BEGINNINGS OF AN
OVERALL PATTERN CHANGE TO A COOLER AND MORE UNSETTLED PERIOD THAT IS
EXPECTED TO LAST THROUGH THE REMAINDER OF THE WEEK. THE TROUGH AS
MAKES ITS APPROACH ALONG THE WEST COAST WILL LOWER 500 MB HEIGHT
FIELDS TO AROUND 570-574DM WITH MID TO HIGH CLOUDS GRADUALLY
SPREADING EASTWARD THROUGH SOUTHERN CA AND AZ THROUGHOUT THE DAY.
AS A RESULT, AFTERNOON TEMPERATURES TODAY WILL LOWER BY 4-5
DEGREES FROM THE AFTERNOON HIGHS FROM YESTERDAY, BUT STILL REMAIN
WELL-ABOVE NORMAL AS READINGS WILL TOP OUT IN THE UPPER 70S TO
LOWER 80S. THESE TEMPERATURE READINGS WILL STILL BE SUFFICIENT TO
RESULT IN AREAS OF MINOR HEATRISK, ALTHOUGH OF LESSER COVERAGE
FROM PREVIOUS DAYS.
THE AFOREMENTIONED TROUGH WILL SLOWLY APPROACH THE CENTRAL CA COAST
ON WEDNESDAY, BUT WILL BE ON A WEAKENING PHASE AS IT DOES. MOST OF
THE ASSOCIATED PVA AND FORCING WITH THIS TROUGH WILL REMAIN TO THE
NORTHWEST OF THE REGION OVER THE GREAT BASIN AND THUS WHERE THE BEST
PRECIPITATION CHANCES AND COVERAGE WILL BE CONFINED. HOWEVER,
MOISTURE VALUES IN THE MID TO UPPER-LEVELS WILL GO UP LATER TODAY
THROUGH WEDNESDAY AS PWATS PEAK UPWARDS OF 0.7-0.8", WHICH IS ABOUT
175-200% OF NORMAL. AS A RESULT, A FEW SHOWERS IN UPSLOPE FLOW MAY
BE SQUEEZED OUT ACROSS THE HIGHER TERRAIN AREAS NORTH AND EAST OF
PHOENIX LATE TONIGHT THROUGH WEDNESDAY MORNING, WITH LITTLE TO NO
ACCUMULATIONS EXPECTED. A FURTHER LOWERING OF 500 MB HEIGHTS TO 568-
573DM DURING THE DAY WEDNESDAY WILL CAUSE AFTERNOON HIGHS TO RETREAT
INTO THE MID TO UPPER 70S ACROSS THE LOWER DESERTS.
LONG TERM /THURSDAY THROUGH EARLY NEXT WEEK/
UNSETTLED WEATHER WILL REMAIN IN PLACE THROUGH THE END OF THE
WEEK AS ANOTHER TROUGHING FEATURE DIVES DOWN THROUGH THE WEST
COAST AND SWINGS THROUGH THE DESERT SOUTHWEST LATE THURSDAY INTO
FRIDAY. MODEL GUIDANCE IN THE LAST COUPLE OF ITERATIONS HAVE
TRENDED A BIT DEEPER WITH THE TROUGH AS IT SWINGS THROUGH THE
REGION, HOWEVER, THE PROGRESSIVE NATURE WILL SORT OF LIMIT ANY
ROBUST MOISTURE ADVECTION AND THUS ANY PRECIPITATION THAT FALLS
WILL BE LIMITED IN COVERAGE, WITH THE GREATEST COVERAGE EXPECTED
MOSTLY ACROSS THE AZ HIGH TERRAIN WHERE NBM POPS RANGE BETWEEN
40-70% WITH CONSIDERABLY LOWER POPS OF 10-40% ACROSS THE LOWER
ELEVATIONS OF WESTERN AND CENTRAL AZ. WITH THE TROUGH PASSAGE,
AFTERNOON HIGH TEMPERATURES ON FRIDAY WILL COOL DOWN TO AROUND 70
DEGREES ACROSS THE SOUTH-CENTRAL AZ LOWER DESERTS (WHICH IS RIGHT
AROUND SEASONAL NORMS) TO MIDDLE 70S ACROSS THE WESTERN DESERTS.
AS THE TROUGH QUICKLY EXITS TO THE EAST LATE FRIDAY INTO EARLY
SATURDAY, A QUIETER WEATHER PATTERN BRIEFLY SETTLES IN OVER THE
WEEKEND AS A TRANSIENT RIDGE MOVES OVERHEAD WITH DRY CONDITIONS AND
SLIGHTLY WARMER TEMPERATURES. ATTENTION THEN TURNS TO ANOTHER, MORE
POTENT LONGWAVE TROUGHING FEATURE THAT IS EXPECTED TO SET UP ALONG
THE WEST COAST HEADING INTO NEXT WEEK, WITH GUIDANCE SHOWING
MULTIPLE SHORTWAVES MOVING ONSHORE AND IF THE OVERALL TRAJECTORY IS
IDEAL, COULD LEAD TO MORE WIDESPREAD PRECIPITATION CHANCES. LATEST
DETERMINISTIC AND ENSEMBLE MODEL SUITE SHOW THE FIRST SHORTWAVE
MOVING THROUGH EARLY NEXT WEEK, DELIVERING THE FIRST WIDESPREAD
CHANCE OF PRECIPITATION WITH NBM POPS RANGING BETWEEN 25-60%
AREAWIDE. HOWEVER, GIVEN THAT THIS POTENTIAL SYSTEM IS STILL
NEARLY A WEEK OUT, LOTS OF UNCERTAINTY STILL REMAINS IN THE
OVERALL DETAILS AND THUS IT WILL PROBABLY TAKE UNTIL THE END OF
THE WEEK TO GET A BETTER GRASP ON HOW THINGS WILL EVOLVE. EVEN
THOUGH THE PRECIPITATION POTENTIAL IS UNCERTAIN, WHAT IS A BIT
MORE CERTAIN IS THAT TEMPERATURES ARE LIKELY TO COOL DOWN SEVERAL
DEGREES EARLY NEXT WEEK WITH THE LATEST NBM DETERMINISTIC SHOWING
HIGHS IN THE LOW 70S ACROSS THE LOWER DESERTS (VALUES MORE TYPICAL
FOR MID-FEBRUARY) WITH THE 25TH PERCENTILE IN THE UPPER 60S,
WHICH WOULD BE MORE LIKELY IF THE CLOUDY/RAINY SCENARIO COMES TO
FRUITION.
AVIATION
UPDATED AT 0535Z.
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:
NO AVIATION WEATHER CONCERNS ARE EXPECTED DURING THE TAF PERIOD.
E'RLY WINDS WILL PREVAIL TONIGHT BUT LOW CONFIDENCE EXISTS FOR THE
TYPICAL W'RLY SHIFT TUESDAY AFTERNOON/EVENING, MAINLY AT KPHX. IF
THIS SHIFT WERE TO NOT OCCUR, VRB TO CALM CONDITIONS MAY BECOME
COMMON. HIGHER CONFIDENCE EXISTS FOR A SW'RLY COMPONENT TAKING
OVER AT OTHER METRO TERMINALS DURING THE AFTERNOON HOURS. HIGH
CLOUD COVERAGE INCREASES BY TUESDAY MORNING, WITH A FEW LOW BASES
AROUND 8-10K FT DEVELOPING DURING THE LATER HALF OF THE FORECAST.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:
BREEZY TO OCCASIONALLY WINDY CONDITIONS DURING THE LATTER PORTION
OF THE FORECAST WINDOW WILL BE THE MAIN AVIATION CONCERN. KBLH
WILL SEE GUSTS AROUND 20 KTS DEVELOP BY THE EARLY AFTERNOON WHILE
STRONGER GUSTS CLOSER TO 25-30 KTS ARRIVE AT KIPL AROUND SUNSET.
BKN-OVC MID AND HIGH STATUS DECKS WILL BE COMMON OVER THE REGION
OVER THE NEXT 24 HOURS.
FIRE WEATHER
WELL-ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS WILL PERSIST
TODAY BEFORE COOLER TEMPERATURES (ALTHOUGH REMAINING ABOVE NORMAL)
ENSUES THROUGH THE REMAINDER OF THE WEEK. MINRH VALUES TODAY WILL
RANGE BETWEEN 20-35% AND WILL CONTINUE TO BE IN THAT RANGE ACROSS
MOST OF THE REGION THROUGH THE REMAINDER OF THE WEEK WITH GOOD TO
EXCELLENT OVERNIGHT RECOVERIES. OCCASIONAL BREEZINESS, ESPECIALLY
ACROSS THE WESTERN DISTRICTS, WILL BE COMMON DURING THE NEXT
SEVERAL DAYS. A WEATHER SYSTEM LATE IN THE WEEK WILL BRING A
40-70% CHANCE OF WETTING RAINS ACROSS THE HIGHER TERRAIN AREAS OF
THE EASTERN DISTRICTS.
PSR WATCHES/WARNINGS/ADVISORIES
AZ...NONE.
CA...NONE.
SHORT TERM...LOJERO
LONG TERM...LOJERO
AVIATION...RW
FIRE WEATHER...LOJERO/BERISLAVICH
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