843
FXUS66 KPDT 270525
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
1025 PM PDT FRI JUN 26 2026
KEY MESSAGES
- ISOLATED TO SCATTERED THUNDERSTORMS OVER THE BLUE MOUNTAINS
THIS AFTERNOON AND EVENING. VERY LOW CHANCE (5-14 PERCENT) TO
SLIGHT CHANCE (15-24 PERCENT) ELSEWHERE.
- BELOW-NORMAL TEMPERATURES, BREEZY TO WINDY WESTERLY WINDS, AND
PERIODS OF SHOWERY WEATHER ARE VERY LIKELY (99 PERCENT
CONFIDENCE) TONIGHT THROUGH THE WEEKEND.
DISCUSSION
WATER VAPOR IMAGERY SHOWS A BROAD AREA OF LOW PRESSURE
STRETCHING FROM THE GULF OF ALASKA TO THE WESTERN CONUS. THERE
ARE CURRENTLY A COUPLE MAIN LOW CENTERS; ONE IS LOCATED OVER
VANCOUVER ISLAND AND ONE FARTHER NORTHWEST IN THE GULF OF
ALASKA. MEANWHILE, A STRONG SHORTWAVE IS TRACKING INLAND OVER
THE WESTERN CONUS ALONG THE SOUTHERN PERIPHERY OF THE LOW.
AT THE SURFACE, COOL CONDITIONS (LOWER 50S TO LOWER 70S) ARE
PRESENT FROM CENTRAL OREGON THROUGH THE BLUE MOUNTAINS AND THEIR
FOOTHILLS. SOMEWHAT WARMER TEMPERATURES (UPPER 60S TO VERY LOW
80S) ARE IN PLACE ACROSS THE COLUMBIA BASIN AND ADJOINING
LOWLANDS OF SOUTH-CENTRAL WASHINGTON AND NORTH-CENTRAL OREGON.
ISOLATED THUNDERSTORMS HAVE DEVELOPED OVER THE BLUE MOUNTAINS
THIS AFTERNOON, AND ARE EXPECTED (80 PERCENT CONFIDENCE) TO
EXPAND IN COVERAGE THROUGH THE AFTERNOON HOURS BEFORE
DIMINISHING LATER THIS EVENING. THERE IS STILL A SLIGHT CHANCE
(15-24 PERCENT) OF THUNDERSTORMS ALONG THE BLUE MOUNTAIN
FOOTHILLS AND PORTIONS OF THE LOWER COLUMBIA BASIN THIS
AFTERNOON AS WELL.
LOOKING AHEAD, CONTINUED BELOW-NORMAL TEMPERATURES, BREEZY TO
WINDY WESTERLY WINDS, AND PERIODS OF SHOWERY WEATHER ARE VERY
LIKELY (99 PERCENT CONFIDENCE) AS THE CLOSED LOW MOVES INLAND
OVER THE PACIFIC NORTHWEST ON SATURDAY BEFORE TRACKING INLAND
SUNDAY INTO EARLY NEXT WEEK.
CLUSTER ANALYSIS OF 12Z ENSEMBLE MEMBERS SHOWS RELATIVELY SMALL
DIFFERENCES IN TIMING/LOCATION AND MAGNITUDE OF THE LOW DURING
THE PERIOD, SO CONFIDENCE IS HIGH IN THE CURRENT FORECAST OF
PREDOMINANTLY BELOW-NORMAL TEMPERATURES INTO EARLY NEXT WEEK.
HOWEVER, EVEN SMALL DIFFERENCES IN THE TRACK/TIMING OF THE LOW
CAN HAVE A SIGNIFICANT IMPACT ON PRECIPITATION.
ON THE TOPIC OF PRECIPITATION, FOR THE PAST SEVERAL RUNS,
DETERMINISTIC AND ENSEMBLE NWP GUIDANCE HAVE BEEN CONSISTENTLY
ADVERTISING A COUPLE SHORTWAVES WRAPPING AROUND THE LOW SUNDAY
AND MONDAY. THESE WILL SERVE AS THE FOCUSING MECHANISM FOR
ADDITIONAL PRECIPITATION, WITH THE BEST CHANCES OF NOTEWORTHY
PRECIPITATION IN WALLOWA COUNTY; CALIBRATED NBM PROBABILITIES
INDICATE A 30-60 PERCENT CHANCE OF 0.50" OR GREATER DURING THE
PERIOD. ELSEWHERE, CURRENTLY FORECASTING LIGHTER PRECIPITATION
(MOUNTAINS AND FOOTHILLS) OR ISOLATED PRECIPITATION (LOWLANDS).
BREEZY TO WINDY WESTERLY WINDS WILL ALMOST CERTAINLY (99
PERCENT CONFIDENCE) PERSIST THROUGH THE WEEKEND AND INTO EARLY
NEXT WEEK. LATEST NBM GUIDANCE SUGGESTS LOW-MEDIUM (20-60
PERCENT) CHANCES OF ADVISORY-LEVEL WIND GUSTS SATURDAY AND
MONDAY THROUGH THE WIND-PRONE REGIONS OF THE CASCADE GAPS AND
LOWER ELEVATIONS. CHANCES ARE HIGHEST (50-95 PERCENT) ON SUNDAY,
AND WIND HEADLINES MAY BE NEEDED.
AVIATION /06Z TAFS THROUGH 06Z SUNDAY/
VFR CONDITIONS CONTINUE TO PREVAIL, WITH NO CIG OR VIS ISSUES
EXPECTED. RADAR CURRENTLY SHOWS A FEW SHOWERS ACROSS THE EAST
MOUNTAINS NOT CURRENTLY IMPACTING ANY TAF SITES. BREEZY WINDS
CONTINUE FOR DLS AND PDT, WHILE ELSEWHERE WILL SEE THEIR WINDS
WEAKEN TO 10-15 KNOTS BY THE EARLY TO LATE AFTERNOON. ANOTHER
ROUND OF LIGHT TO MODERATE SHOWERS IS POSSIBLE IN BDN AND RDM
WITH PROB30'S OCCURRING IN THE EARLY AFTERNOON HOURS.
PRELIMINARY POINT TEMPS/POPS
PDT 47 69 46 72 / 20 10 10 10
ALW 53 71 51 73 / 20 10 10 10
PSC 52 76 50 80 / 0 0 0 10
YKM 50 74 49 80 / 0 0 0 0
HRI 50 73 48 77 / 0 0 0 0
ELN 46 67 46 71 / 0 0 10 0
RDM 40 62 34 67 / 20 20 20 0
LGD 47 63 44 65 / 100 40 30 40
GCD 43 62 39 65 / 90 70 40 20
DLS 53 70 51 72 / 10 20 10 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...NONE.
DISCUSSION...86
AVIATION...95
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