342
FXUS66 KPDT 290505
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
1005 PM PDT SAT MAR 28 2026
KEY MESSAGES
- DRY CONDITIONS THROUGH SUNDAY MORNING
- A RETURN OF ACTIVE WEATHER LATE SUNDAY AFTERNOON INTO MONDAY
WITH LIGHT PRECIPITATION IN THE MOUNTAINS
- MORE WIDESPREAD PRECIPITATION CHANCES, BREEZY WINDS, AND
COOLER CONDITIONS WEDNESDAY THROUGH THURSDAY
DISCUSSION
AFTERNOONS BECOME BREEZY TODAY AND A LITTLE MORE WINDY IN A FEW
SPOTS ON SUNDAY. THIS IS FOCUSED ACROSS THE HIGHER TERRAIN AND
MOUNTAIN ZONES ABOVE 2500-3000 FEET, SUCH AS THE SIMCOE AND
JOHNDAY/OCHOCO HIGHLANDS AND KITTITAS/YAKIMA VALLEYS AND IN THE
3 TO 7 PM WINDOW. SUNDAY NIGHT, A WEAK ATMOSPHERIC RIVER WILL
INFLUENCE THE INTERIOR NORTHWEST WITH A BROAD 200-300 KG/MS IVT,
AND A MAX OF ABOUT 18 TO 22 MM IVW INTO THE LOWER COLUMBIA
BASIN. THIS APPEARS MAINLY A MOUNTAIN AND HIGHLANDS EPISODE
AS SNOW LEVELS CRASH BEHIND THE COLD FRONT AS THE PRECIPITATION
PROBABILITY RAMPS DOWNWARD ON MONDAY. DURING THE TIME FRAME OF
EXPECTED PEAK POPS, THE SNOW LEVELS ARE EXPECTED TO RANGE FROM
AROUND 3000-3500 FT AGL ACROSS THE WA CASCADES AND AROUND
4500-6000 FT AGL OVER THE NORTHERN BLUE MOUNTAINS. LIMITED
WINTER WEATHER IMPACTS IN PART SUE TO WARM ROAD TEMPS (CURRENTLY
IN THE 40-60 DEGREE SURFACE TEMPS EVEN HOURS BEFORE PEAK
HEATING TODAY).
MONDAY AND TUESDAY APPEAR SIMILAR IN TERMS OF WINDS AND WIND
GUSTS ACROSS THE FORECAST AREA WITH WINDS IN THE 10 TO 15 MPH
RANGE FOR GUSTS IN THE LOWLANDS AND HIGHER GUSTS RANGING FROM 15
TO 30 MPH INTO HIGHER TERRAIN. A STRONGER AR IS FORECAST BY THE
ENSEMBLES AND EC/GFS CONTROL RUNS TO DEVELOP WEDNESDAY
(EXTENDING THROUGH THURSDAY) WITH MORE MEANINGFUL IMPACTS IN
TERMS SNOW FOR THE MOUNTAIN ZONES AND AND WINDY CONDITIONS OVER
A WIDER AREA. THE WWRF (GFS/EC) 9KM FREEZING LEVEL PLAN VIEW
SHOWS THE COLD FRONT MOVING ACROSS THE REGION BY WEDNESDAY. NBM
ENSEMBLE MEAN AT THIS TIME WOULD HAVE THE CRESTS OF THE
WASHINGTON AND OREGON CASCADES RECEIVE AROUND 1 FOOT ON AVERAGE
OF SNOWFALL WITH A COUPLE OF FEET UP ON THE CONE TOPS.
AS FAR AS PASS LEVEL IMPACTS, THE WSSI-P GIVES A 50 TO 70%
CHANCES FOR MINOR IMPACTS BASED ON SNOWFALL ALONE, AS THE
HIGHEST SNOW AMOUNTS FROM THE OF THE NBM MEAN ALONG I-90 IS 5 TO
7 INCHES LOCALLY. WHAT DOES FALL WILL BE A HEAVY WET, LOW SLR
SNOW WITH HIGHER PROBABILITIES IMPACT FROM SNOW LOAD THAN SNOW
AMOUNTS.
AVIATION /06Z TAFS THROUGH 06Z MONDAY/
VFR CONDITIONS PREVAIL FOR THE NEXT 24-HOURS WITH FEW PROVISIONS
IMPEDING FLIGHT LEVELS. MOSTLY DRY CONDITIONS WILL MAINTAIN,
WITH THE EXCEPTION OF PROB30 RAIN SHOWERS FORMING IN PDT AND
ALW. NOT EXPECTING SUB-VFR FOR THE MAJORITY OF THE FORECAST
PERIOD. WINDS WILL BE BREEZY IN MOST LOCATIONS STARTING IN THE
LATE TOMORROW MORNING/EARLY AFTERNOON WITH GUSTS UP TO 20-30
KNOTS. OTHERWISE, NO SIGNIFICANT CIG OR VIS ISSUES EXPECTED.
PRELIMINARY POINT TEMPS/POPS
PDT 63 37 55 31 / 0 0 20 20
ALW 62 41 55 33 / 0 0 40 40
PSC 66 39 60 33 / 0 0 10 10
YKM 64 35 58 28 / 0 0 10 10
HRI 65 39 59 32 / 0 0 10 10
ELN 57 33 51 26 / 0 0 20 10
RDM 65 32 60 26 / 0 0 10 10
LGD 65 35 60 31 / 0 0 30 50
GCD 66 36 64 32 / 0 0 10 30
DLS 63 40 57 33 / 0 0 20 20
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...NONE.
DISCUSSION...71
AVIATION...95
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