323
FXUS66 KPDT 280549
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
1049 PM PDT SAT JUN 27 2026
KEY MESSAGES
- WIDESPREAD BREEZY TO WINDY WESTERLY WINDS SUNDAY, STRONGEST
THROUGH THE KITTITAS VALLEY
- BELOW-NORMAL TEMPERATURES, BREEZY TO LOCALLY WINDY WESTERLY
WINDS, AND OCCASIONAL MOUNTAIN SHOWERS THROUGH THE WEEK
DISCUSSION
WATER VAPOR SATELLITE IMAGERY THIS AFTERNOON SHOWS THE CENTER
OF AN UPPER LOW HAS COME ONSHORE, THOUGH REGIONAL RADAR IMAGERY
SO FAR TODAY HAS SHOWN SHOWER ACTIVITY HAS MOSTLY BEEN FOCUSED
OUTSIDE OF THE FORECAST AREA. SHOWER ACTIVITY ACROSS THE CASCADE
CREST/EAST SLOPES AND ACROSS THE EASTERN MOUNTAINS WILL DEVELOP
OVER THE NEXT COUPLE HOURS AS THE LOW CONTINUES TO PUSH INLAND.
INCREASING SURFACE INSTABILITY AND MODEST LOW TO MID LEVEL
LAPSE RATES WILL ALSO ALLOW FOR A FEW SHOWERS TO DEVELOP INTO
ISOLATED THUNDERSTORMS THROUGH THIS EVENING. OTHERWISE, BREEZY
WEST TO NORTHWEST WINDS HAVE DEVELOPED THROUGH THE CASCADE GAPS
INTO THE COLUMBIA BASIN TODAY.
THE UPPER CLOSED LOW PUSHING INTO THE PACNW TODAY WILL START THE
PROLONGED TREND OF UPPER LEVEL TROUGHING OVER THE PACNW THROUGH
MOST THE NEXT WEEK. THE UPPER LOW WILL TRACK EAST ACROSS THE
REGION THROUGH MONDAY, WITH THE MAIN SHOWER ACTIVITY TIED TO A
SERIES OF SHORTWAVES ROUNDING THE LOW BOTH DAYS. THAT SAID,
SHOWER ACTIVITY WILL MAINLY BE CONFINED TO PORTIONS OF THE
CASCADES, NORTHERN BLUES, AND WALLOWAS THROUGH THIS PERIOD, WITH
BEST CHANCES OVER THE WALLOWA MOUNTAINS. CLUSTER ENSEMBLE
GUIDANCE IS IN GOOD AGREEMENT OF SHORTWAVE TROUGHS DIVING DOWN
THE AK/BC COASTLINES AND ACROSS THE PACNW TUES/WED AND THURSDAY,
WHICH WILL BRING ANOTHER ROUND OF LIGHT MOUNTAIN RAIN SHOWERS
ACROSS THE FORECAST AREA THOSE DAYS (CONFIDENCE 55-75%).
AS MENTIONED EARLIER, BREEZY WINDS HAVE DEVELOPED IN THE LOWER
ELEVATIONS TODAY, AND ARE EXPECTED TO PERSIST THROUGH MUCH OF
THE WEEK AS THE TROUGHING PATTERN HOLDS OVER THE PACNW. THE
STRONGEST WINDS OF THE WEEK WILL DEVELOP TOMORROW AFTERNOON AS
A SURFACE LOW DEVELOPS IN NORTHERN MT, RESULTING IN A
TIGHTENING CROSS-CASCADE PRESSURE GRADIENT. WINDS WILL GENERALLY
BE 15-30 MPH WITH GUSTS UP TO 40 MPH, HOWEVER WINDS THROUGH THE
KITTITAS VALLEY ARE EXPECTED TO INCREASE TO 25-35 MPH AND GUSTS
TO AROUND 50 MPH TOMORROW (CONFIDENCE 75-85%). OTHERWISE, DAILY
WINDS WILL BE 15-25 MPH WITH GUSTS TO AROUND 35 MPH THROUGHOUT
THE WEEK.
LASTLY, THE PERSISTENT TROUGH PATTERN WILL KEEP TEMPERATURES
MUCH COOLER THAN NORMAL THROUGH THE WEEK, WITH AFTERNOON
TEMPERATURES GENERALLY 5 TO 15 DEGREES BELOW NORMAL (CONFIDENCE
60-75%). THIS MEANS THAT AFTERNOON TEMPERATURES IN THE LOWER
ELEVATIONS WILL BE IN THE 70S, WITH LOCALLY 80S, THROUGHOUT MUCH
OF THE WEEK. IN THE MOUNTAINS, MID-ELEVATIONS WILL GENERALLY BE
IN THE UPPER 50S TO 60S, WITH LOWER TO MID 50S IN THE HIGH-
ELEVATIONS. LAWHORN/82
AVIATION /06Z TAFS THROUGH 06Z MONDAY/
VFR CONDITIONS ARE FORECAST AT ALL SITES FOR THE NEXT 24 HOURS.
WINDS WILL BE BREEZY TO WINDY AND GUSTY THROUGH THE MAJORITY OF
THE PERIOD, STRONGEST DURING THE AFTERNOON AND EVENING HOURS
SUNDAY. THERE IS A LOW (10-30 PERCENT) CHANCE OF RAIN SHOWERS
OVERNIGHT INTO SUNDAY MORNING AT PDT/ALW/PSC, BUT OPTED TO FORGO
ANY PROB30 OR TEMPO GROUPS FOR RAIN SHOWERS IN THE 06Z TAFS DUE
TO INSUFFICIENT CONFIDENCE IN TIMING/LOCATION.
PRELIMINARY POINT TEMPS/POPS
PDT 49 73 50 72 / 10 20 10 10
ALW 54 74 53 72 / 10 30 20 30
PSC 55 81 54 78 / 10 10 0 10
YKM 51 81 53 81 / 0 0 0 0
HRI 52 77 52 75 / 0 10 0 10
ELN 51 71 52 72 / 0 0 0 10
RDM 41 67 40 70 / 30 0 0 0
LGD 45 65 47 69 / 30 40 20 30
GCD 42 65 44 71 / 50 40 10 0
DLS 54 73 55 72 / 10 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...WIND ADVISORY FROM 10 AM TO 11 PM PDT SUNDAY FOR WAZ026.
OR...NONE.
DISCUSSION...82
AVIATION...86
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