975
FXUS66 KPDT 011017
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
217 AM PST SUN MAR 1 2026
KEY MESSAGES
- AN UPPER LOW MOVING ONSHORE WILL BRING PRECIPITATION MAINLY TO
CENTRAL AND SOUTHERN OREGON THROUGH MONDAY.
- AN UPPER TROUGH WILL BRING BETTER CHANCES FOR PRECIPITATION
LATER TUESDAY INTO THURSDAY.
- GUSTY WINDS ARE POSSIBLY WITH THE TROUGH WEDNESDAY INTO
THURSDAY.
DISCUSSION
AN UPPER LOW OFF THE COAST WILL MOVE EASTWARD TODAY. AS IT DOES,
PRECIPITATION WILL MOVE ONSHORE AHEAD OF THE LOW IN SOUTHWEST
FLOW. THE LOW MILL MOVE ONSHORE IN NORTHERN CALIFORNIA TONIGHT
AND MORE PRECIPITATION IS EXPECTED. THIS LOW WILL MOVE EASTWARD
AND OUT OF THE AREA ON MONDAY.
SNOW LEVELS WILL BE QUITE HIGH...GENERALLY HIGHER THAN 6500
FEET AS THIS LOW MOVES THROUGH, SO LITTLE, IF ANY SNOW IS
EXPECTED, EXCEPT FOR THE HIGHEST ELEVATIONS. LIQUID QPF VALUES
WILL RANGE FROM A FEW HUNDREDTHS TO AROUND 0.25 INCHES, WITH
SOME OF THE HIGHER ELEVATIONS RECEIVING BETWEEN 0.25 TO 0.50
INCHES.
A RIDGE WILL BUILD IN BEHIND THE DEPARTING LOW FOR MONDAY INTO
MUCH OF TUESDAY, BRINGING DRY WEATHER. ACROSS WESTERN SECTIONS
OF THE AREA AND THE MOUNTAINS, PRECIPITATION WILL BEGIN TO MOVE
IN ON TUESDAY BUT WILL HOLD OFF OVER MOST LOCATIONS UNTIL
TUESDAY NIGHT.
BY LATER TUESDAY AND INTO TUESDAY NIGHT AN UPPER TROUGH WILL
MOVE ACROSS THE PACIFIC NORTHWEST AND BRING MORE WIDESPREAD
PRECIPITATION CHANCES THAT WILL CONTINUE INTO WEDNESDAY BEFORE
BEING MORE CONFINED TO THE MOUNTAINS ON THURSDAY.
SNOW LEVELS WILL START OFF RELATIVELY HIGH, WITH VALUES BETWEEN
5000 AND 5500 FEET IN THE NORTH AND 5500 AND 6500 FEET IN THE
SOUTH AND EAST. HOWEVER, SNOW LEVELS WILL FALL AND BY LATER
WEDNESDAY WILL BE BETWEEN 4000 AND 5000 FEET ACROSS THE REGION
AND WILL FALL TO BETWEEN 3000 AND 3500 FEET IN MANY AREAS BY
THURSDAY MORNING. THIS WOULD PUT SNOW LEVELS BELOW THE HIGHER
PASSES BY THURSDAY MORNING.
LIQUID EQUIVALENT PRECIPITATION RANGES FROM A FEW HUNDREDTHS TO
AROUND 0.10 INCHES IN THE LOWER ELEVATIONS TO OVER 1 INCH ALONG
THE CRESTS OF THE BLUE MOUNTAINS, WALLOWAS AND CASCADES.
HOWEVER, GIVEN THE TIME OF YEAR IT IS DIFFICULT FOR ANY SNOW TO
ACCUMULATE ON ROAD SURFACES DURING THE DAY UNLESS IT FALLS HARD
OR IT IS EXCEPTIONALLY COLD. AT NIGHT, ACCUMULATION IS POSSIBLE,
BUT IT WOULD STILL REQUIRE COLD ROAD SURFACES. IT WOULD STILL
BE DEPENDENT ON WHAT TIME MOST OF THE PRECIPITATION WERE TO
OCCUR, AND IN THIS CASE SOME IS DEFINITELY GOING TO OCCUR DURING
THE DAYTIME HOURS. TIMING IS STILL A BIT OF A QUESTION, AND
THAT LEADS TO UNCERTAINTY IN THE ACCUMULATION AMOUNTS. SO WHILE
SOME ACCUMULATION IS POSSIBLE, HOW MUCH IS THE BIG QUESTION. THE
GREATEST CHANCES ARE ABOVE 5000 FEET, BUT BELOW THAT IT IS A
LOT MORE. THE NBM PROBABILITIES OF SNOW ACCUMULATIONS >=4
INCHES ALONG THE CASCADE CREST IN THE WEDNESDAY-THURSDAY
TIMEFRAME RANGES FROM 30 TO 70 PERCENT. HOWEVER, THE NBM
PROBABILITIES OF SNOW ACCUMULATIONS >=6 INCHES DECREASES IN MOST
AREAS TO UNDER 30 PERCENT WITH SOME HIGHER VALUES AT THE HIGHER
ELEVATIONS.
AS THE TROUGH MOVES ACROSS THE AREA, WEDNESDAY INTO THURSDAY,
WINDS WILL INCREASE AND BECOME GUSTY. WIND GUSTS ON WEDNESDAY,
ESPECIALLY FOR THE NORMALLY BREEZIER LOCATIONS LIKE THE CASCADE
GAPS, COLUMBIA BASIN AND FOOTHILLS OF THE BLUE MOUNTAINS WILL
SEE GUSTS IN THE 25 TO 35 MPH RANGE, WITH GUSTS AS HIGH AS 40
MPH. BREEZY CONDITIONS WILL LINGER INTO THURSDAY BUT LOOK TO BE
A TAD LOWER. NBM PROBABILITY OF WIND GUSTS >= 39 MPH ON
WEDNESDAY IN THESE AREAS RANGE FROM ABOUT 60 TO 80 PERCENT. NBM
PROBABILITIES OF WIND GUSTS >=47 MPH ARE GENERALLY LESS THAN 50
PERCENT.
HIGH TEMPERATURES LOOK TO BE ABOVE NORMAL MONDAY AND TUESDAY
THEN CLOSE TO NORMAL FROM WEDNESDAY ONWARD.
AVIATION /12Z TAFS THROUGH 12Z MONDAY/
VFR CONDITIONS AND LIGHT WINDS ARE EXPECTED AT ALL TAF SITES
EXCEPT FOR RDM AND BDN. RDM AND BDN WILL SEE SOME MVFR
CONDITIONS LATE TONIGHT AND INTO INTO MONDAY IN -RA.
PRELIMINARY POINT TEMPS/POPS
PDT 53 36 57 37 / 10 20 10 0
ALW 53 37 56 40 / 0 10 10 0
PSC 56 33 60 38 / 0 0 0 0
YKM 55 32 59 36 / 0 0 0 0
HRI 55 35 60 38 / 0 10 0 0
ELN 51 30 55 34 / 0 0 0 0
RDM 53 36 55 32 / 40 60 20 0
LGD 56 40 57 34 / 20 40 30 0
GCD 56 41 53 34 / 60 70 50 0
DLS 56 39 61 42 / 10 10 10 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...NONE.
DISCUSSION...77
AVIATION...77
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