823
FXUS66 KPDT 281027
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
227 AM PST SAT FEB 28 2026
KEY MESSAGES
- AN UPPER LOW WILL BRING PRECIPITATION TO PORTIONS OF CENTRAL
AND SOUTHERN OREGON LATER TODAY INTO SUNDAY.
- ANOTHER UPPER LOW AND TROUGH WILL BRING MORE WIDESPREAD
PRECIPITATION BEGINNING LATER TUESDAY INTO WEDNESDAY.
- NEAR TO ABOVE NORMAL TEMPERATURES ARE EXPECTED THROUGH THE
WEEKEND AND INTO NEXT WEEK.
DISCUSSION
THE UPPER RIDGE OVER THE AREA WILL WEAKEN AND MOVE EASTWARD AS
AN UPPER LOW OFF THE COAST MOVES CLOSER TO THE REGION. MOISTURE
AHEAD OF THE LOW WILL BEGIN TO MOVE ONSHORE IN CENTRAL AND
SOUTHER OREGON LATER THIS MORNING AND INTO THE AFTERNOON,
CONTINUE OVERNIGHT AND INTO SUNDAY BEFORE DECREASING EARLY ON
MONDAY. THE HIGHEST PROBABILITIES WILL BE OVER THE MOUNTAINS,
BUT THERE WILL BE AT LEAST LOW CHANCES OVER THE LOWER
ELEVATIONS.
QPF AMOUNTS WILL BE GENERALLY LIGHT, ONLY A FEW HUNDREDTHS TO
PERHAPS 0.10 INCHES AT THE LOWER ELEVATIONS AND 0.10 TO 0.20
INCHES IN MOST OTHER AREAS WITH AMOUNTS UPWARDS OF 0.50 INCHES
AT THE HIGHEST ELEVATIONS AND ALONG THE CASCADE CREST. SNOW
LEVELS ARE EXPECTED TO BE QUITE HIGH, AND WILL RISE THROUGH
SUNDAY BEFORE DECREASING AGAIN INTO MONDAY. SNOW LEVELS WILL
RISE TO OVER 7500 FEET IN MOST AFFECTED LOCATIONS. AS A RESULT,
LITTLE SNOW ACCUMULATION IS EXPECTED, AND ONLY AT THE HIGHEST
ELEVATIONS.
PRECIPITATION WILL REND ON MONDAY AND A RIDGE WILL BUILD IN,
BRINGING DRY WEATHER OVER MUCH OF THE AREA THROUGH TUESDAY.
OVER WESTERN AREAS, SOME PRECIPITATION MAY BEGIN TO MOVE IN
DURING THE DAY ON TUESDAY.
AN UPPER LOW AND TROUGH WILL BEGIN MOVE TOWARDS THE REGION ON
TUESDAY AND PRECIPITATION AHEAD OF THE TROUGH WILL MOVE IN TO
THE AREA FROM THE WEST. THE LOW AND TROUGH WILL THEN MOVE ACROSS
THE PACIFIC NORTHWEST ON WEDNESDAY, BRINGING WIDESPREAD
PRECIPITATION CHANCES BEFORE IT MOVES EAST AND OUT OF THE AREA
ON THURSDAY.
SNOW LEVELS INITIALLY START OUT FAIRY HIGH, BETWEEN 5500 AND
6500 FEET, BUT BY WEDNESDAY NIGHT,THEY WILL DECREASE BELOW 4000
FEET IN MANY AREAS. LIQUID EQUIVALENT QPF IS AROUND AN INCH
ALONG THE CRESTS OF THE BLUE AND WALLOWA MOUNTAINS AND OVER AND
INCH ALONG THE CASCADES. THERE LOOKS TO BE AT LEAST SOME SNOW,
ESPECIALLY FOR THE HIGHER PASSES. DEPENDING ON HOW MUCH FALLS
AND WHEN, THERE COULD BE SEVERAL INCHES AND WE WILL KEEP AND EYE
ON TIMING. WE ARE IN THAT TIME OF YEAR WHERE IT IS MORE
DIFFICULT FOR SNOW TO ACCUMULATE DURING THE DAY DUE TO HIGHER
SUN ANGLE AND WARMER GROUND AND WHILE NIGH TIME ACCUMULATIONS
REMAIN POSSIBLE, IF THE ROAD TEMPERATURES REMAIN WARM AIR
TEMPERATURES HAVE TO BE COLDER OR SNOW HAS TO FALL HEAVY.
ON THURSDAY, THERE SHOULD JUST BE SOME LINGERING PRECIPITATION
IN THE MOUNTAINS. BEYOND THURSDAY, THERE IS SOME DISCREPANCY IN
THE GUIDANCE, THE GFS DETERMINISTIC BRINGS IN SOME RIDGING AND
DRY WEATHER IN RESPONSE TO A DIGGING UPPER LOW OVER THE
SOUTHWEST. THE ECMWF IS NOT NEARLY AS STRONG WITH THIS FEATURE
AND, THEREFORE DOES NOT HAVE THE UPSTREAM RIDGING AND IS WETTER.
THE ENSEMBLE CLUSTERS ARE TRENDING TOWARD THE DEEPER LOW IN THE
SOUTHWEST, BUT ONLY SLIGHTLY. OF COURSE THIS IS ABOUT A WEEK
AWAY AND THINGS CAN CHANGE.
AS THE TROUGH AND LOW MOVE THROUGH WEDNESDAY THERE WILL BE SOME
GUSTY WINDS IN THE NORMALLY BREEZIER LOCATIONS, LIKE THE
COLUMBIA BASIN, FOOTHILLS OF THE BLUE MOUNTAINS AND CASCADE
GAPS. WINDS COULD GUST IN THE 25 TO 35 MPH RANGE AND POSSIBLY AS
HIGH AS 40 MPH, THOUGH AT THIS TIME WIND ADVISORIES DO NOT LOOK
TO BE NECESSARY. BREEZY CONDITIONS WILL LINGER INTO THURSDAY,
THOUGH THEY SHOULD BE LOWER. NBM PROBABILITIES OF WIND GUSTS
>= 39 MPH ON WEDNESDAY ARE GENERALLY 60 TO 80 PERCENT ACROSS
MUCH OF THESE AREAS. HOWEVER THE PROBABILITIES OF WIND GUSTS
>= 47 MPH ARE MAINLY 30 PERCENT OR LESS.
HIGH TEMPERATURES WILL BE NEAR OR ABOVE NORMAL THROUGH THE WEEK.
AVIATION /12Z TAFS THROUGH 12Z SUNDAY/
VFR CONDITIONS AND WIND LESS THAN 10 KTS ARE EXPECTED THROUGH
THE TAF PERIOD.
PRELIMINARY POINT TEMPS/POPS
PDT 53 35 52 36 / 0 10 10 20
ALW 54 35 52 37 / 0 0 10 10
PSC 54 33 55 34 / 0 0 0 10
YKM 53 33 55 33 / 0 0 0 0
HRI 54 35 55 36 / 0 0 10 10
ELN 49 30 51 31 / 0 0 0 0
RDM 56 33 53 34 / 10 40 40 30
LGD 57 37 56 38 / 0 10 30 40
GCD 58 38 55 40 / 10 40 60 60
DLS 53 38 55 38 / 0 10 20 10
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...NONE.
DISCUSSION...77
AVIATION...77
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