289
FXUS66 KPDT 260542
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
1042 PM PDT THU JUN 25 2026
KEY MESSAGES
- MULTIPLE RED FLAG WARNINGS IN EFFECT TODAY DUE TO BREEZY
WINDS AND LOW RELATIVE HUMIDITY
- COOLER, BREEZY, AND SHOWERY WEATHER IS LIKELY (99 PERCENT
CONFIDENCE) FRIDAY INTO THE WEEKEND
- CHANCE (25-35 PERCENT) OF THUNDERSTORMS FOR THE BLUE
MOUNTAINS ON FRIDAY, WITH A VERY LOW CHANCE (5-14 PERCENT) TO
SLIGHT CHANCE (15-24 PERCENT) ELSEWHERE
DISCUSSION
WATER VAPOR IMAGERY SHOWS A CLOSED LOW MOVING SOUTHEAST ALONG
THE COAST OF BRITISH COLUMBIA AND SOUTHEAST ALASKA. MEANWHILE, A
SHORTWAVE WRAPPING AROUND THE BASE OF THE LOW WILL CONTINUE TO
TRACK INLAND OVER THE PACIFIC NORTHWEST DURING THE AFTERNOON AND
OVERNIGHT HOURS, WITH PRECIPITATION EXPECTED TO ACCOMPANY THE
WAVE.
BREEZY TO WINDY WESTERLY WINDS AND LOW RELATIVE HUMIDITY ARE
PRESENT ACROSS MUCH OF THE REGION AND RED FLAG WARNINGS HAVE
BEEN ISSUED FOR MULTIPLE FIRE WEATHER ZONES (SEE FIRE WEATHER
SECTION BELOW FOR DETAILS).
A TRANSITION TO A COOLER, WETTER PATTERN IS LIKELY (99 PERCENT
CONFIDENCE) BY TONIGHT AS THE SHORTWAVE MOVES OVERHEAD,
FOLLOWED BY THE PARENT CLOSED LOW OVER THE WEEKEND. CLUSTER
ANALYSIS OF 00Z 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
BELOW-NORMAL TEMPERATURES FRIDAY THROUGH THE WEEKEND. HOWEVER,
EVEN SMALL DIFFERENCES IN THE TRACK/TIMING OF THE LOW CAN HAVE A
SIGNIFICANT IMPACT ON PRECIPITATION; THE TREND IN ENSEMBLE
GUIDANCE HAS BEEN TO KEEP THE LOWER ELEVATIONS RELATIVELY DRY
WITH PRECIPITATION FOCUSED OVER THE MOUNTAINS. THE LATEST NBM
SHOWS A 10-30 PERCENT CHANCE OF A WETTING RAIN (0.10" OR
GREATER) ACROSS THE COLUMBIA BASIN, A MEDIUM CHANCE (40-60
PERCENT) ALONG THE BLUE MOUNTAIN FOOTHILLS, AND A HIGH CHANCE
(70-100 PERCENT) FOR THE CASCADE AND BLUE MOUNTAINS AS WELL AS
THE VALLEYS AND BASINS WITHIN THE BLUE MOUNTAINS.
AVIATION /06Z TAFS THROUGH 06Z SATURDAY/
A LINE OF MOSTLY LIGHT TO MODERATE RAIN SHOWERS IS OCCURRING
ACROSS THE REGION. VFR CONDITIONS ARE EXPECTED TO PREVAIL
THROUGH THE PERIOD WITH VERY SLIGHT CHANCES (5-15% CHANCE) OF
MVFR CONDITIONS TEMPORARILY DEVELOPING OVERNIGHT IN THE MORE
MODERATE/HEAVIER RAIN SHOWERS. RAIN WILL CONTINUE THROUGH THE
LATE EVENING TO EARLY MORNING HOURS. ELEVATED TO BREEZY WINDS
WILL PREVAIL FOR THE DLS AND PSC, WITH AFTERNOON DEVELOPMENT IN
BDN/RDM.
FIRE WEATHER
FIRE WEATHER CONCERNS ARE PRESENT TODAY, FOCUSED PRIMARILY
ACROSS FIRE WEATHER ZONES OR691, WA691, WA690, OR703, AND
WA694 AS BREEZY TO WINDY WESTERLY WINDS (10-20 MPH WITH GUSTS OF
20-35 MPH) OVERLAP WITH LOW RELATIVE HUMIDITY OF 10-20 PERCENT.
COOLER, BREEZY, AND SHOWERY WEATHER WITH ISOLATED TO SCATTERED
THUNDERSTORMS (MAINLY FOR THE MOUNTAINS) IS THEN FORECAST FRIDAY
THROUGH THE WEEKEND AS AN UPPER-LEVEL CLOSED LOW PRESSURE
SYSTEM MOVES OVER THE PACIFIC NORTHWEST. WHILE ISOLATED TO
SCATTERED THUNDERSTORMS ARE FORECAST OVER THE BLUE MOUNTAINS, HAVE
NOT ISSUED ANY FIRE WEATHER HEADLINES FOR A COUPLE REASONS.
FIRST, MANY OF THE FIRE WEATHER ZONES WHICH ARE FORECAST TO
RECEIVE LIGHTNING HAVE NOT YET BEEN DECLARED READY FOR RED FLAG
WARNINGS THIS SEASON. SECOND, ANTICIPATING THE MAJORITY OF THE
THUNDERSTORMS OVER THE BLUE MOUNTAINS TO EITHER PRODUCE A
WETTING RAIN (0.10" OR MORE) OR BE PRECEDED AND/OR FOLLOWED BY A
WETTING RAIN OVERNIGHT THROUGH THE WEEKEND (70-95 PERCENT
CHANCE). ELSEWHERE, THE CHANCE OF WETTING RAIN IS LOW (10-30
PERCENT) FOR THE COLUMBIA BASIN TO MEDIUM (40-60 PERCENT) ALONG
THE BLUE MOUNTAIN FOOTHILLS.
PRELIMINARY POINT TEMPS/POPS
PDT 52 74 47 69 / 40 70 30 10
ALW 58 75 53 70 / 20 70 30 10
PSC 56 80 52 75 / 30 20 10 0
YKM 55 79 50 73 / 30 10 0 0
HRI 54 78 50 73 / 60 40 10 0
ELN 50 71 46 66 / 20 30 10 10
RDM 46 70 40 62 / 70 30 20 30
LGD 53 69 47 63 / 40 90 90 40
GCD 51 71 43 62 / 80 90 80 80
DLS 56 75 53 70 / 50 20 10 10
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...NONE.
DISCUSSION...86
AVIATION...95
FIRE WEATHER...86
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