524
FXUS66 KPDT 282348 CCA
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
348 PM PST SAT FEB 28 2026
KEY MESSAGES
- LIGHT RAIN AND HIGH MOUNTAIN SNOW ACROSS CENTRAL AND EASTERN
PORTIONS OF OREGON THROUGH MONDAY MORNING.
- WIDESPREAD PRECIPITATION CHANCES RETURN TUESDAY INTO
WEDNESDAY, WITH PERSISTENT LIGHT TO MODERATE SNOW IN THE
MOUNTAINS THROUGH THE END OF THE WEEK.
- POTENTIAL FOR BREEZY TO GUSTY WINDS (GUSTS 35-50 MPH)
DEVELOPING WEDNESDAY.
DISCUSSION
SATELLITE IMAGERY THIS AFTERNOON SHOWS AN OFFSHORE
UPPER LOW SPINNING MOSTLY HIGH CLOUDS ACROSS OR AND SOUTHERN WA.
MEANWHILE, REGIONAL RADAR SHOWS SHOWERS HAVE DEVELOPED ACROSS
SOUTHWEST OR AND ARE SLOWLY SPREADING NORTHWARD. AT THIS TIME,
HOWEVER, SHOWER ACTIVITY REMAINS SOUTH OF DESCHUTES COUNTY.
TONIGHT THROUGH MONDAY MORNING: SHOWER CHANCES WILL INCREASE
ACROSS PORTIONS OF CENTRAL OR, JOHN DAY BASIN, AND THE OCHOCO-
JOHN DAY HIGHLANDS THROUGH TOMORROW AS THE UPPER LOW OFFSHORE
CONTINUES TO PUSH EAST. THE BEST CHANCES FOR LIGHT RAIN IN THE
LOWER ELEVATION AREAS (CENTRAL OR AND JOHN DAY BASIN) WILL
DEVELOP JUST BEFORE THE UPPER LOW MOVES INTO NORTHERN CA SUNDAY
AFTERNOON AND EVENING. BY LATE MONDAY MORNING, PRECIPITATION
CHANCES WILL TAPER OFF ACROSS THE AFFECTED AREAS AS THE LOW
TRANSITIONS INTO A TROUGH OVER THE CA/NV BORDER.
SNOW LEVELS WILL REMAIN ABOVE 6.5KFT TO 7KFT DURING A MAJORITY
OF THE LOWS TRANSIT THROUGH THE REGION, OWING TO THE LOW
REMAINING TO THE SOUTH OF AS WELL AS DIRECTING A MILD SOUTHERLY
FLOW INTO THE FORECAST AREA. THIS WILL RESULT IN VERY LOW SNOW
TOTALS ACROSS MOUNTAIN AREAS (OR CASCADE PEAKS, MT BACHELOR,
PAULINA PEAK, STRAWBERRY RANGE), WITH SNOW AMOUNTS BY MONDAY
MORNING TOTALING AT BEST 1 TO 3 INCHES (CONFIDENCE 70-85%).
OTHERWISE, RAIN SHOWERS ACROSS THE REMAINDER OF THE SOUTHERN
PORTIONS OF THE FORECAST AREA WILL RESULT IN RAIN AMOUNTS OF
AROUND 0.1 TO 0.2 INCHES THROUGH MONDAY MORNING.
MONDAY THROUGH TUESDAY MORNING: A TRANSIENT UPPER RIDGE WILL
MOVE OVER THE PACNW DURING THIS PERIOD, RESULTING IN A RETURN
OF AREA-WIDE DRY CONDITIONS. SOME WARM AIR ADVECTION WITH THE
UPPER RIDGE WILL BRING TEMPERATURES CLOSER TO THE LOWER TO MID
60S ACROSS MUCH OF THE COLUMBIA BASIN MONDAY AND TUESDAY
AFTERNOONS. OTHERWISE, SKY COVER WILL BEGIN TO INCREASE LATE
MONDAY NIGHT INTO TUESDAY MORNING FROM THE WEST, AS THE NEXT
UPPER LEVEL TROUGH APPROACHES THE PACNW. THIS MAY LIMIT VIEWING
POTENTIAL FOR THE LUNAR ECLIPSE TUESDAY MORNING, WITH CLOUD
COVER EXPECTED TO COVER THE WESTERN THIRD OF THE FORECAST AREA
BY THE TIME OF THE ECLIPSE TOTALITY (3AM-4AM PST). THE ONLY
SAVING GRACE WITH THE INCOMING CLOUD COVER IS THAT IT MAY START
OFF AS A THINNER OR SCATTERED CIRRUS DECK (CONFIDENCE 30-60%).
TUESDAY THROUGH FRIDAY: THERE IS GREAT AGREEMENT AMONGST
ENSEMBLE AND DETERMINISTIC GUIDANCE THAT AN UPPER TROUGH PASSAGE
TUESDAY EVENING THROUGH WEDNESDAY NIGHT WILL BRING WIDESPREAD
PRECIPITATION CHANCES TO THE PACNW. SNOW LEVELS WILL START OFF
ABOVE 5KFT WITH THE APPROACH OF THE TROUGH, BUT DROP TO 4KFT TO
5KFT AS THE TROUGH MOVES INLAND TUESDAY NIGHT INTO WEDNESDAY
MORNING. THE HEAVIEST OF THE PRECIPITATION WILL ALIGN WITH SNOW
LEVELS JUST FALLING TO OR BELOW THE SURFACE ALONG THE CASCADE
CREST TUESDAY NIGHT, RESULTING IN WET SNOW ACCUMULATIONS OF 2 TO
4 INCHES BY THE END OF WEDNESDAY MORNING(CONFIDENCE 60-70%).
THROUGH THE REST OF WEDNESDAY, SNOW LEVELS WILL CONTINUE TO
LOWER TO 3KFT TO 4KFT, RESULTING IN MORE WIDESPREAD SNOW IN THE
MOUNTAINS, THOUGH SNOW RATES WILL BECOME VERY LIGHT AS THE
TROUGH AXIS PASSES EAST OF THE FORECAST AREA.
BELOW THE MOUNTAINS, MOST LOWER ELEVATION LOCATIONS WILL SEE AT
LEAST A CHANCE (35-50%) OF LIGHT RAIN (~0.05 INCHES OR HIGHER)
DEVELOP AS THE TROUGH AXIS AND AN ATTENDANT COLD FRONT SWEEP
THROUGH THE AREA. HEAVIEST RAIN AMOUNTS WILL BE ALONG THE
NORTHERN BLUE MOUNTAIN FOOTHILLS, WHERE THERE IS A 50-80% CHANCE
OF ACCUMULATIONS GREATER THAN 0.15 INCHES THROUGH THURSDAY
MORNING. OTHERWISE, ENSEMBLE GUIDANCE IS DEPICTING BREEZY WINDS
(GUSTS 35-50MPH) DEVELOPING WITH THE AFOREMENTIONED COLD FRONT
PASSAGE WEDNESDAY (CONFIDENCE 60-70%), WITH STRONGEST WINDS
ALONG THE CASCADE PEAKS/RIDGES AND RIDGES IN THE COLUMBIA BASIN.
THURSDAY INTO FRIDAY, THERE REMAINS GOOD AGREEMENT AMONGST
ENSEMBLE GUIDANCE THAT AN ACTIVE NORTHWEST FLOW ALOFT WILL
RESULT IN PERSISTENT LIGHT SNOW AND RAIN/SNOW CHANCES ALONG THE
CASCADE CREST/EAST SLOPES, NORTHERN BLUE MOUNTAINS, AND EAGLE
CAPS. AROUND HALF OF THE ENSEMBLE CLUSTER MEMBERS (ECMWF, GFS,
AND CANADIAN) ALSO DEPICT LIGHT RAIN ALONG THE BLUE MOUNTAIN
FOOTHILLS AND CENTRAL OR THURSDAY AFTERNOON, AND ~60% OF MEMBERS
KEEPING THE LOWER ELEVATIONS DRY FRIDAY. OTHERWISE, LOCALLY
BREEZY WEST WINDS (25-40MPH) WILL REDEVELOP DURING THE DAY
THURSDAY AND FRIDAY (CONFIDENCE 35-60%). LAWHORN/82
AVIATION /00Z TAFS THROUGH 00Z MONDAY/
VFR CONDITIONS TO
PREVAIL THROUGH THE PERIOD. A SYSTEM APPROACHING THE REGION TO
THE SOUTH WILL BRING CIGS DOWN TO AOA 5KFT TO 7KFT AGL AT SITES
RDM/BDN LATER THIS AFTERNOON THROUGH TONIGHT. A PROB30 CHANCE OF
LIGHT RAIN SHOWERS WERE INCLUDED AT SITE BDN FOR LATE THIS
AFTERNOON INTO THE EVENING. AS THE OFFSHORE SYSTEM APPROACHES
TOMORROW MORNING, RAIN SHOWER CHANCES WILL INCREASE AT SITES
RDM/BDN AFTER 19Z. WINDS WILL BE LIGHT, LESS THAN 12KTS,
THROUGH THE PERIOD. LAWHORN/82
PRELIMINARY POINT TEMPS/POPS
PDT 35 53 37 57 / 0 10 20 10
ALW 36 53 37 57 / 0 10 10 10
PSC 33 56 35 60 / 0 0 10 0
YKM 32 55 32 59 / 0 0 0 0
HRI 35 55 35 60 / 0 10 10 10
ELN 30 51 31 55 / 0 0 0 0
RDM 33 52 36 56 / 20 50 50 10
LGD 37 56 39 57 / 10 30 40 30
GCD 38 55 41 54 / 20 60 70 40
DLS 38 56 39 61 / 0 10 20 10
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...NONE.
DISCUSSION...82
AVIATION...82
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