141
FXUS66 KPDT 270927
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
227 AM PDT MON APR 27 2026
KEY MESSAGES
- CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS THIS AFTERNOON
IN THE EASTERN MOUNTAINS
- TEMPERATURES GRADUALLY WARMING TO ABOVE NORMAL THROUGH THE
REMAINDER OF THE WEEK
DISCUSSION
TODAY AND TUESDAY: SATELLITE IMAGERY TONIGHT
SHOWS SCATTERED DECKS OF MID TO HIGH LEVEL CLOUD COVER ACROSS
PORTIONS OF SOUTHEAST WA AND NORTHEAST OR, WITH VERY LITTLE
SHOWER ACTIVITY NOTED ON REGIONAL RADAR.
TODAY, A WEAK SHORTWAVE UNDER A NORTH NORTHWEST FLOW ALOFT WILL
DIVE ACROSS THE INLAND PACNW, RESULTING IN ISOLATED TO SCATTERED
SHOWER CHANCES ACROSS THE EASTERN MOUNTAINS THIS AFTERNOON.
A WEAK THUNDERSTORM OR TWO MAY DEVELOP THIS AFTERNOON OVER THE
EASTERN MOUNTAINS AS DEVELOPING SHOWERS TAP INTO A WEAK POOL OF
INSTABILITY DEVELOPING INTO THE AFTERNOON (CAPE <500 J/KG AND
HIGH LOW LEVEL LAPSE RATES). TUESDAY, ANOTHER SHORTWAVE WILL
MOVE ACROSS THE REGION, BUT WILL TRACK ACROSS EASTERN WA INTO
FAR NORTHEAST OR DUE TO UPPER RIDGING PUSHING TOWARDS THE PACNW.
SHOWER ACTIVITY WILL BE LIMITED THE NORTHERN BLUES AND RIDGES
IN WALLOWA COUNTY IN THE AFTERNOON.
WEDNESDAY THROUGH FRIDAY: UPPER LEVEL RIDGING WILL BUILD OVER
THE REGION THROUGH THE LATTER HALF OF THE WORK WEEK (CONFIDENCE
70-85%). THIS WILL RESULT IN DRYING AND WARMING CONDITIONS
ACROSS MUCH OF THE FORECAST AREA. HIGH TEMPERATURES WILL WARM
WELL ABOVE NORMAL, WITH MID 70S IN THE MID ELEVATIONS (CENTRAL
OR) AND UPPER 70S TO LOWER 80S IN THE LOWER ELEVATIONS.
SATURDAY AND SUNDAY: ENSEMBLE CLUSTER GUIDANCE IS IN GOOD
AGREEMENT THAT A POSITIVELY TILTED UPPER TROUGH WILL SLIDE OVER
THE PACNW THROUGH THE WEEKEND, HOWEVER THERE IS DISAGREEMENT ON
THE DEPTH AND POSITION OF THE TROUGH AS IT MOVES INLAND.
REGARDLESS OF THE POSITION, ENSEMBLE CLUSTER SOLUTIONS INDICATE
A SOUTHWEST FLOW INTO THE INLAND PACNW, KEEPING TEMPERATURES
ABOVE NORMAL OVER THE WEEKEND. THE UPPER TROUGH AND SOUTHWEST
FLOW ALOFT WILL ALSO PROMOTE SHOWER CHANCES OVER THE EASTERN
MOUNTAINS BOTH SATURDAY AND SUNDAY AFTERNOONS, WITH A SLIGHT
CHANCE OF ISOLATED THUNDERSTORMS DEVELOPING AS WELL (CONFIDENCE
30-50%). LAWHORN/82
AVIATION /06Z TAFS THROUGH 06Z TUESDAY/
VFR CONDITIONS WILL
PERSIST THROUGH THE PERIOD. THE ONLY EXCEPTION WILL BE KBDN,
WHICH IS EXPECTED TO LOWER TO MVFR CONDITIONS AROUND 12Z DUE TO
NEARBY PRESCRIBED FIRE SMOKE REDUCING VISIBILITIES TO AROUND 3SM
AND CEILINGS OF 7KFT. KRDM/KBDN WILL SEE BREEZY WINDS BEGINNING
20-21Z WITH GUSTS OF 15-20KTS. 20-25KT GUSTS WILL ALSO BE
POSSIBLE FOR KDLS AFTER 17Z.OTHERWISE, THE REMAINING SITES WILL
SEE CIGS OF 25KFT TO SKC AND WINDS BELOW 10KTS.
PRELIMINARY POINT TEMPS/POPS
PDT 65 41 67 40 / 10 0 0 0
ALW 65 45 67 44 / 30 10 10 0
PSC 71 43 72 42 / 0 0 0 0
YKM 69 41 71 41 / 0 0 0 0
HRI 69 43 69 41 / 0 0 0 0
ELN 63 40 62 39 / 10 0 0 0
RDM 61 30 65 31 / 0 0 0 0
LGD 58 35 64 39 / 50 10 10 0
GCD 58 33 64 37 / 40 10 10 0
DLS 68 44 67 42 / 10 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...NONE.
DISCUSSION...82
AVIATION...90
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