172
FXUS66 KPDT 161746
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
1046 AM PDT FRI OCT 16 2026
KEY MESSAGES
1. DRY AND WARM CONDITIONS THROUGH THE DAY TODAY
2. BREEZY CONDITIONS THROUGH THE GRANDE RONDE VALLEY TODAY
3. BREEZY THROUGH THE WIND PRONE AREAS SATURDAY AND LIGHT SHOWERS IN
THE CASCADES
DISCUSSION
CURRENT NIGHTTIME SATELLITE IS SHOWING MOSTLY CLEAR SKIES OVER THE
REGION. THIS WILL ALLOW FOR COOLER OVERNIGHT TEMPERATURES IN THE
UPPER 30S AND LOW 40S. WARMER TEMPERATURES ALONG THE FOOTHILLS OF
THE BLUES DUE TO THE EASTERLY DOWNSLOPE WIND REGIME CAUSING
TEMPERATURES TO BE WARMER IN THE MID TO UPPER 40S WITH ISOLATED 50S.
TEMPERATURES WILL BE IN THE UPPER 30S ACROSS PORTIONS OF CENTRAL OR
AND THE EASTERN MOUNTAINS. THE BASIN, GORGE, FOOTHILLS AND
YAKIMA/KITTITAS VALLEYS WILL SEE TEMPERATURES IN THE UPPER 30S TO
LOW 40S.
NOT A LOT OF CHANGE FOR THE FORECAST SINCE LAST NIGHT/ DETERMINISTIC
MODELS CONTINUE TO BE IN FIRM AGREEMENT WITH THE UPPER LEVEL RIDGE
REMAINING OVER THE AREA THROUGH FRIDAY AFTERNOON. TEMPERATURES WILL
PEAK TODAY WITH IN OFFICE CALCULATIONS CONTINUING TO SHOW
TEMPERATURES TO BE NEARLY 15-20 DEGREES ABOVE SEASONAL NORMAL.
LOOKING AT THE ENSEMBLE GUIDANCE, 90% OF THE HREF RAW ENSEMBLES SHOW
TEMPERATURES TO BE IN THE LOW TO MID 70S THROUGH THE BASIN,
FOOTHILLS, GORGE AND YAKIMA/KITTITAS VALLEYS WHILE CENTRAL OR AND
THE JOHN DAY BASIN WILL SEE UPPER 70S WITH SOME POSSIBLE 80S MIXED
IN.
MODELS SHOW THAT TODAY (FRIDAY) WILL SEE THE SYNOPTIC TRANSITION OF
THE UPPER LEVEL RIDGE MOVING EAST AND AN UPPER LEVEL TROUGH BUILDING
INTO THE REGION FROM BRITISH COLUMBIA. AS THE RIDGE LEAVES THE
REGION, CURRENT RUNS OF THE DETERMINISTIC MODELS SHOW A WEAK SURFACE
LEVEL HIGH IN TREASURE VALLEY WHILE A WEAK SURFACE LOW IS OVER THE
COLUMBIA BASIN. THIS IS THE PERFECT SYNOPTIC SET UP FOR EASTERLY
BREEZY WINDS THROUGH THE GRANDE RONDE VALLEY. EASTERLY WINDS ARE
CURRENTLY ALREADY FLOWING OVER THE BLUES BASED OFF GROUND
OBSERVATIONS. WINDS THROUGH THE AREA WILL BEGIN TO PICK AFTER
MIDNIGHT THURSDAY REACHING ITS PEAK AFTER 11 AM AND PERSISTING
THROUGH 5 PM FRIDAY. HREF RAW ENSEMBLES SHOW SUSTAINED WINDS OF 20-
25 MPH WITH GUSTS OF 30-35 MPH WITH SOME ISOLATED 40 MPH GUSTS WITH
ABOVE 80% AGREEMENT.
SATURDAY MODELS SHOW THE UPPER LEVEL TROUGH BEGINNING TO DIG INTO
THE PACNW. AS THE LEADING EDGE OF THE TROUGH WEDGES ITSELF AGAINST
THE CASCADES, THE PRESSURE GRADIENTS BEGIN TO TIGHTEN LEADING TO
BREEZY CONDITIONS THROUGH THE TYPICAL WINDS PRONE GAP AREAS. LOOKING
AT THE NBM RAW ENSEMBLES, 60-80% ARE IN AGREEMENT THAT THE KITTITAS
VALLEY WILL SEE WINDS BETWEEN 20-25 MPH SUSTAINED WINDS WITH GUSTS
OF 30-35 MPH. THE GORGE WILL SEE 15-20 MPH SUSTAINED WINDS AND GUSTS
OF 25-30 MPH. WITH THIS FRONT, LIGHT PRECIPITATION ALONG THE
CRESTS OF THE CASCADES IS EXPECTED WITH NEAR 0.03 INCHES IN 24
HOURS AND 90% HREF ENSEMBLE AGREEMENT.
BY THE BEGINNING OF NEXT WEEK MODELS SHOW THE UPPER LEVEL TROUGH
FORM INTO A LOW PRESSURE SYSTEM AND BEGIN TO MOVE TO THE SOUTH.
MODELS SHOW THE LOW TO CUTOFF AND MOVE TO THE SOUTH OF THE REGION.
THIS WILL BRING CHANCES OF WRAP AROUND MOISTURE TO THE BLUES AND THE
WALLOWA MOUNTAINS. CLUSTERS ARE HOWEVER STRUGGLING TO RESOLVE THE
REGIME WITH TIMING, POSITIONING AND STRENGTH ALL VARYING BETWEEN
THE MODELS. THE ONLY AGREEMENT THE MODELS SEEM TO HAVE IS THE FACT
THERE IS A LOW PRESSURE SYSTEM MAKING ITS WAY ALONG THE WEST
COAST.
AVIATION /18Z TAFS THROUGH 18Z SATURDAY/
VFR CONDITIONS WILL PERSIST THROUGH THE PERIOD. WINDS WILL
GENERALLY BE LIGHT (UNDER 10 KNOTS) WITH GUSTS AROUND 15-20 KNOTS
POSSIBLE FOR DLS, PDT, AND ALW TOWARDS THE END OF THE TAF PERIOD (50-75%
CONFIDENCE). GUSTS OF AROUND 15 KNOTS ARE ALSO POSSIBLE FOR BDN FROM
AROUND 06Z-10Z (50% CONFIDENCE). SKIES WILL LIKELY (GREATER THAN 75%
CHANCE) REMAIN MOSTLY CLEAR FOR MUCH OF THE TAF PERIOD, WITH
CLOUD COVER REMAINING ABOVE 25KFT.
PRELIMINARY POINT TEMPS/POPS
PDT 73 43 69 35 / 0 0 0 0
ALW 74 50 70 41 / 0 0 0 0
PSC 69 39 72 35 / 0 0 0 0
YKM 70 43 70 37 / 0 0 0 0
HRI 70 41 70 37 / 0 0 0 0
ELN 67 40 61 31 / 0 0 0 0
RDM 79 35 67 29 / 0 0 0 0
LGD 76 45 70 36 / 0 0 0 0
GCD 76 39 73 35 / 0 0 0 0
DLS 75 47 69 39 / 0 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...RED FLAG WARNING UNTIL 7 PM PDT THIS EVENING FOR ORZ694.
DISCUSSION...90
AVIATION...21/71
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