029
FXUS66 KPDT 171743
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
1043 AM PDT SAT OCT 17 2026
KEY MESSAGES
1. BREEZY THROUGH THE WIND PRONE AREAS SATURDAY AND LIGHT SHOWERS IN
THE CASCADES
2. DRY AND COOLER TEMPERATURES OVER THE WEEKEND
3. PATTERN SHIFT AT THE BEGINNING OF THE WEEK WILL BRING SEASONAL
TEMPERATURES THROUGH MIDWEEK
DISCUSSION
CURRENT NIGHTTIME SATELLITE IS SHOWING MOSTLY CLOUDY SKIES OVER THE
REGION. THIS WILL KEEP OVERNIGHT TEMPERATURES A LITTLE WARMER THAN
THE LAST FEW NIGHTS. NBM SHOWS OVERNIGHT TEMPERATURES TO BE IN THE
UPPER 30S TO LOW 40S THROUGH CENTRAL OR AND THE EASTERN MOUNTAINS
WHILE THE REMAINDER OF THE LOWER ELEVATIONS WILL SEE LOW TO MID 50S
WITH SOME ISOLATED 50S ALONG THE FOOTHILLS OF THE BLUES DUE TO
CONTINUED DOWNSLOPING WINDS.
SATURDAY MODELS SHOW THE NEXT SYNOPTIC PATTERN TO MAKE ITS WAY SOUTH
FROM THE GULF OF ALASKA. 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 HREF RAW ENSEMBLES, 70-80% 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. ALONG WITH THE WINDS THROUGH
THE GAPS, LIGHT PRECIPITATION IS EXPECTED ALONG THE CRESTS OF THE
CASCADES. MODELS SHOW 0.03 INCHES OF RAIN IN A 24 HOUR PERIOD WITH
80-90% PROBABILITIES.
BY SATURDAY AFTERNOON THE MODELS SHOW THE SHORTWAVE MOVING OFF TO
THE NORTHEAST AND A MORE ZONAL FLOW SET UP DOMINATING. MODELS SHOW
DRY CONDITIONS TO PERSIST UNDER THIS FLOW THROUGH SUNDAY AFTERNOON
WHEN THE NEXT SYNOPTIC SYSTEM BEGINS TO INFILTRATE THE REGION. AS
THE SYSTEM MOVES CLOSER TO THE AREA, SOUTHWEST FLOW WILL TAKE OVER
AND DRY CONDITIONS WILL PERSIST.
BY TUESDAY MODELS SHOW THE UPPER LEVEL LOW TO BE SHIFTING SOUTH OFF
THE COAST OF CALIFORNIA AND UNDERCUTTING THE REGION. SOUTHWEST FLOW
WILL CONTINUE TO DOMINATE THROUGH TUESDAY. CLUSTERS ARE STRUGGLING
TO RESOLVE THE POSITIONING AND AMPLITUDE OF THE LOW. HOWEVER, MODELS
DO SHOW THAT THE LOW CONTINUES TO MOVE SOUTHWARDS AND ONSHORE, THE
POTENTIAL FOR SOME WRAP AROUND MOISTURE ON THE EASTERN SIDE OF THE
LOW MAKING ITS WAY INTO THE EASTERN MOUNTAINS. QPF CLUSTERS ARE
SHOWING THE HIGHEST CHANCES TO BE THURSDAY WITH LOW CONFIDENCE (20-
30%) FOR 0.01 INCHES OF RAIN. WITH THE UNCERTAINTY IN THE CLUSTERS,
CONFIDENCE IN THE POTENTIAL FOR RAIN IS LOW (<20%).
AVIATION /18Z TAFS THROUGH 18Z SUNDAY/
VFR CONDITIONS TO PERSIST FOR ALL SITES EXCEPT KBDN AND KRDM
HAVING LOW CLOUD BASES BELOW 3000 RESULTING IN MVFR CONDITIONS
FORM 5Z TO 17Z. ALL SITES HAVE INCREASING CLOUD COVER TOWARDS
THE EVENING INTO THE OVERNIGHT WITH LOWERING CLOUD BASES. KDLS
AND KPDT HAVE GUSTS OF 20KT THROUGH THE LATE AFTERNOON HOURS.
CALMER CONDITIONS AND HIGHER CLOUD BASES APPEAR TOWARDS THE END
OF THE TAF PERIOD.
PRELIMINARY POINT TEMPS/POPS
PDT 69 35 63 36 / 0 0 0 0
ALW 69 40 64 42 / 0 0 0 0
PSC 72 36 66 37 / 0 0 0 0
YKM 70 36 64 39 / 0 0 0 0
HRI 70 38 65 37 / 0 0 0 0
ELN 61 31 61 35 / 10 0 0 0
RDM 66 30 63 29 / 0 0 0 0
LGD 70 36 68 40 / 0 0 0 0
GCD 73 36 72 39 / 0 0 0 0
DLS 69 40 68 44 / 0 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...NONE.
DISCUSSION...90
AVIATION...07/95
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