436
FXUS66 KPDT 251816
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
1116 AM PDT SAT OCT 25 2025
UPDATED AVIATION DISCUSSION
AVIATION...18Z TAFS
VFR CONDITIONS WILL CARRY ON THROUGHOUT THIS
PERIOD, THOUGH MVFR CONDITIONS COULD OCCUR IF LOW CLOUD DECKS
FURTHER DEVELOPS. SHOWERS AND BREEZY TO WINDY CONDITIONS WILL
CONTINUE AS THE FRONTAL SYSTEM PASSES ACROSS OUR FORECAST AREA.
KPDT, KRDM, KBDN, KYKM, KALW AND KPSC WILL SEE SUSTAINED WINDS OF
15-25KT WITH GUSTS AT 25-35KTS STARTING THIS AFTERNOON THROUGH
OVERNIGHT. HOWEVER, WIND GUSTS MAY DECREASE LATE EVENING FOR
KRDM/KBDN. LLWS OF 23045KTS AT KALW AND 22045KTS AT KPSC AROUND
01Z. THESE CONDITIONS SHOULD DECREASE OVERNIGHT INTO SUNDAY
MORNING FOR THESE AFOREMENTIONED SITES, BUT KALW/KPSC MIGHT SEE AN
UPTICK IN WINDS UP TO 12KTS (<30% CHANCE). KDLS COULD HAVE WINDS
INCREASE TO 12KTS THIS EARLY AFTERNOON AS WELL, BUT WILL BECOME
LIGHT AROUND 02Z. FEASTER/97
PREV DISCUSSION
/ISSUED 1018 AM PDT SAT OCT 25 2025/
UPDATE
SATELLITE IMAGERY SHOWS AN AREA OF LOW PRESSURE
CHURNING OFFSHORE, WITH TWO LOW CENTERS NOTED. A COLD FRONTAL
BOUNDARY IS PUSHING EASTWARD INTO THE CASCADES, WITH WINDS
EXPECTED TO RAMP ACROSS THE REGION THROUGH THE AFTERNOON AS IT
TRACKS INLAND AND A ROBUST LOW-LEVEL JET OVERSPREADS THE REGION.
CAMS CONTINUE TO SUGGEST A CONVECTIVE LINE WILL DEVELOP ALONG THE
FRONT BY 1-3 PM PDT THIS AFTERNOON ACROSS THE EASTERN HALF OF THE
COLUMBIA BASIN INTO THE BLUE MOUNTAINS. MADE SOME MODIFICATIONS TO
THE THUNDER FORECAST, AND NOTED GUSTY OUTFLOW WINDS IN THE
GRIDDED FORECAST. STRONGER SHOWERS AND/OR THUNDERSTORMS WILL BE
CAPABLE OF PRODUCING SEVERE WIND GUSTS (50 KTS OR GREATER) ACROSS
THE AFOREMENTIONED REGION, AND SPC'S DAY 1 CONVECTIVE OUTLOOK HAS
THE AREA IN A MARGINAL RISK WITH WIND AS THE ONLY ANTICIPATED
HAZARD.
REGARDING HEADLINES, BASED ON LATEST 12Z HREF GUIDANCE AND
OBSERVATIONAL TRENDS HAVE PUSHED UP THE ONSET TIMING OF WIND
ADVISORIES IN CENTRAL AND NORTH-CENTRAL OREGON AS WELL AS ALONG
THE FOOTHILLS OF THE BLUE MOUNTAINS AND LOWER COLUMBIA BASIN IN
OREGON.
PREV DISCUSSION
/ISSUED 214 AM PDT SAT OCT 25 2025/
DISCUSSION
THE NEXT FEW DAYS LOOK TO BRING FAIRLY ACTIVE
WEATHER ACROSS THE REGION. AN UPPER LEVEL LOW WILL MOVE NORTHEAST
TOWARDS SOUTHERN BRITISH COLUMBIA AND A BROAD TROUGH WILL MOVE
INTO THE PACIFIC NORTHWEST THROUGH THE WEEKEND. SEVERAL SHORT
WAVES WILL MOVE THROUGH THE TROUGH.
PRECIPITATION IS EXPECTED TO INCREASE THIS AFTERNOON AREA-WIDE.
HIGHEST LIQUID EQUIVALENT QPF TODAY WILL BE IN THE OREGON
CASCADES WHERE OVER AN INCH IS EXPECTED WITH MUCH LESS ELSEWHERE
AND ONLY A FEW HUNDREDTHS IN THE LOWER ELEVATIONS. THERE WILL BE A
LULL IN PRECIPITATION TONIGHT BEFORE ANOTHER ROUND DEVELOPS ON
SUNDAY. LIQUID EQUIVALENT QPF WILL BE HIGHEST ON THE CASCADE CREST
WHERE OVER 1 INCH IS FORECAST WITH UP TO 0.50 INCHES IN THE BLUES
AND 0.05 TO 0.10 IN THE LOWER ELEVATIONS.
SNOW LEVELS WILL INITIALLY START OFF FAIRLY HIGH, BETWEEN
4000-4500 FEET IN THE WASHINGTON CASCADES AND BETWEEN 6500-7500
FEET ELSEWHERE. HOWEVER, THEY WILL DROP DURING THE DAY AND INTO
TONIGHT AS THE TROUGH MOVES ONSHORE AND WILL BE AROUND 4500-5000
FEET IN MOST AREAS LATE TODAY AND GENERALLY BETWEEN 3000-3500 FEET
BY SUNDAY MORNING. SNOW LEVELS WILL THEN RISE A BIT TO BETWEEN
3500-4500 FEET BY SUNDAY AFTERNOON.
PREVIOUSLY ISSUED WINTER WEATHER ADVISORIES WILL REMAIN UNCHANGED
BUT WILL NEED TO KEEP AN EYE ON THINGS AS PRECIPITATION DEVELOPS
FOR ANY POSSIBLE UPGRADES, ESPECIALLY OVER THE OREGON CASCADES.
AS THE TROUGH MOVES ONSHORE, THERE WILL BE A STRONG LOW LEVEL JET
AND THERE IS HIGH (70-90 PERCENT PROBABILITIES) OF WINDS REACHING
AT LEAST 45 MPH OR GREATER OF MUCH OF THE REGION, ESPECIALLY
ACROSS THE COLUMBIA BASIN, SIMCOE HIGHLANDS AND PORTIONS OF
CENTRAL OREGON. THE NBM SHOWS PROBABILITIES OF WIND GUSTS >=39 MPH
OF 90 PERCENT OR GREATER OF MUCH OF THE REGION. THEM NBM
PROBABILITIES OF WINDS >= 47 MPH RANGE FROM 40 PERCENT TO 80
PERCENT ACROSS THE SAME AREAS. A WIND ADVISORY WILL BE ISSUED FROM
LATE THIS AFTERNOON TO EARLY SUNDAY MORNING.
ALSO AS THE LOW LEVEL JET MOVES THROUGH, COUPLED WITH COOL AIR
ALOFT DUE TO THE TROUGH, THERE IS THE POSSIBILITY OF A RUMBLE OF
THUNDER, ESPECIALLY OVER FAR EASTERN OREGON THIS AFTERNOON.
PRECIPITATION DECREASES SUNDAY NIGHT, THOUGH THERE WILL STILL BE
SOME LOW CHANCES MONDAY. TUESDAY LOOKS MAINLY DRY OUTSIDE OF THE
MOUNTAINS AS A RIDGE BUILD IN. A WEAK SYSTEM COULD BRING MAINLY
MOUNTAIN PRECIPITATION FOR WEDNESDAY FOLLOWED BY DRYING THURSDAY
AND PERHAPS ANOTHER WEAK SYSTEM BY THE END OF THE WEEK.
PRELIMINARY POINT TEMPS/POPS
PDT 63 38 55 35 / 90 30 70 50
ALW 61 41 55 38 / 100 40 70 70
PSC 62 39 55 34 / 90 20 50 30
YKM 54 34 52 29 / 100 40 70 20
HRI 62 39 56 35 / 80 20 60 30
ELN 50 29 47 27 / 100 60 70 40
RDM 55 29 49 25 / 90 50 80 30
LGD 58 31 52 32 / 100 50 70 80
GCD 59 33 50 30 / 90 30 80 50
DLS 58 41 54 39 / 100 80 90 50
PDT WATCHES/WARNINGS/ADVISORIES
OR...WIND ADVISORY FROM 5 PM THIS AFTERNOON TO 7 AM PDT SUNDAY FOR
ORZ041.
WIND ADVISORY UNTIL 5 AM PDT SUNDAY FOR ORZ044-507.
WINTER WEATHER ADVISORY FROM 8 AM SUNDAY TO 8 AM PDT MONDAY FOR
ORZ502.
WIND ADVISORY UNTIL 2 AM PDT SUNDAY FOR ORZ508-510-511.
WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 2 AM PDT
MONDAY FOR ORZ509.
WA...WIND ADVISORY FROM 5 PM THIS AFTERNOON TO 7 AM PDT SUNDAY FOR
WAZ024-027>029-521.
WINTER WEATHER ADVISORY FROM 8 AM SUNDAY TO 8 AM PDT MONDAY FOR
WAZ030.
WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 11 PM PDT
SUNDAY FOR WAZ522.
MORNING UPDATE...86
DISCUSSION...90
AVIATION...97
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