049
FXUS66 KPDT 162307
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
407 PM PDT SUN AUG 16 2026
KEY MESSAGES
- SOUTHWEST FLOW THROUGH MONDAY WILL BRING SHOWER AND ISOLATED
THUNDERSTORM CHANCES MAINLY TO FAR EASTERN OREGON.
- INCREASED GAP WIND POTENTIAL MONDAY NIGHT INTO TUESDAY.
- ANOTHER CHANCES OF SHOWERS AND THUNDERSTORMS TOWARD THE
WEEKEND.
DISCUSSION
SOUTHWEST FLOW WILL CONTINUE THROUGH MONDAY. SEVERAL SHORT
WAVES WILL MOVE THROUGH THE FLOW. THESE SHORT WAVES COUPLED
WITH RESIDUAL MOISTURE COULD TRIGGER SHOWERS AND ISOLATED
AFTERNOON THUNDERSTORMS, MAINLY FOR WALLOWA COUNTY, BUT OTHER
MOUNTAIN AREAS CAN'T BE RULED OUT.
BY TUESDAY, THE PACIFIC NORTHWEST GETS INTO MORE OF A SPLIT FLOW
PATTERN AND AS A RESULT, WEST WINDS WILL INCREASE ACROSS THE
AREA. WINDS WILL BECOME GUSTY BEGINNING MONDAY NIGHT AND INTO
TUESDAY, WITH WIND GUSTS 20 TO 30 MPH, WITH SOME LOCATIONS
POSSIBLY AS HIGH AS 35 MPH, IN THE USUALLY BREEZIER AREAS SUCH
AS THE KITTITAS VALLEY, SIMCOE HIGHLANDS, BLUE MOUNTAIN
FOOTHILLS, COLUMBIA BASIN AND GORGE. NBM PROBABILITIES OF WIND
GUSTS >=25 MPH ARE >60 PERCENT, WHILE NBM PROBABILITIES OF WIND
GUSTS >= 39 MPH ARE GENERALLY 50 PERCENT OR LESS.
RH VALUES DO DECREASE A BIT BETWEEN MONDAY AND TUESDAY AND WITH
THE GUSTY WINDS, FIRE WEATHER CONDITIONS WILL BE ELEVATED, AND
COULD BECOME CRITICAL. TUESDAY WILL HAVE TO BE MONITORED FOR ANY
FIRE WEATHER HEADLINES.
BEYOND TUESDAY, THE MIDWEEK PERIOD LOOK RATER QUIET, IN DRY WEST
TO SOUTHWEST FLOW.
HOWEVER, BY THE WEEKEND AN AREA OF LOW PRESSURE WILL MOVE
NORTHWARD OFF THE COAST. THIS LOW IS THEN EXPECTED TO MOVE
ONSHORE IN OREGON OR WASHINGTON AT SOME POINT ON SATURDAY. THERE
IS STILL SOME DISAGREEMENT AS TO WHERE THE LOW COMES ASHORE AND
HOW STRONG IT WILL BE AND THE NATURAL UNCERTAINTY IN A FORECAST
5 DAYS OUT, BUT SHOWER AND THUNDERSTORM CHANCES DO LOOK TO
INCREASE, ESPECIALLY FOR THE MOUNTAINS AS WE HEAD INTO THE
WEEKEND.
AVIATION /00Z TAFS THROUGH 00Z TUESDAY/
VFR CONDITIONS TO
PREVAIL THROUGH THE PERIOD. LOW CONFIDENCE (20%) IN ANY SMOKE
IMPACTS REDEVELOPING AT SITES, THOUGH IF IMPACTS DO OCCUR EXPECT
REDUCTION IN VSBY IN THE OVERNIGHT AND EARLY MORNING HOURS.
WINDS WILL BE AROUND 15KTS WITH GUSTS UP TO 25KTS AT SITES DLS
THROUGH THIS EVENING. OTHERWISE, WINDS WILL BE LIGHT AT ALL
SITES THROUGH THE PERIOD. LAWHORN/82
FIRE WEATHER
ISOLATED SHOWERS AND THUNDERSTORMS (20-25% TODAY) AND (<20%
MONDAY) ARE POSSIBLE MAINLY ACROSS WALLOWA COUNTY IN SOUTHWEST
FLOW.
AS THE FLOW BECOMES MORE WESTERLY MONDAY NIGHT INTO TUESDAY,
WINDS WILL INCREASE AND BECOME GUSTY, WITH GUSTS AS HIGH AS 20
TO 30 MPH AND POSSIBLY AS HIGH AS 35 MPH ACROSS THE KITTITAS
VALLEY, SIMCOE HIGHLANDS, BLUE MOUNTAIN FOOTHILLS AND THE
COLUMBIA BASIN AND GORGE. THESE WINDS AND LOW RELATIVE
HUMIDITIES WILL YIELD ELEVATED FIRE WEATHER CONDITIONS TUESDAY
AND COULD BRING CRITICAL CONDITIONS ONCE AGAIN.
BEYOND THAT, THERE IS THE POTENTIAL FOR MORE THUNDERSTORMS GOING
INTO NEXT WEEKEND.
PRELIMINARY POINT TEMPS/POPS
PDT 57 88 58 89 / 0 0 0 0
ALW 63 90 64 90 / 0 0 0 0
PSC 59 93 60 94 / 0 0 0 0
YKM 60 93 62 93 / 0 0 0 0
HRI 61 92 63 92 / 0 0 0 0
ELN 58 89 60 86 / 0 0 0 0
RDM 51 87 49 89 / 0 0 10 0
LGD 57 91 57 90 / 0 10 20 0
GCD 56 91 56 91 / 0 0 10 0
DLS 60 92 63 89 / 0 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...AIR QUALITY ALERT UNTIL NOON PDT MONDAY FOR WAZ026-522-523.
OR...AIR QUALITY ALERT UNTIL NOON PDT MONDAY FOR ORZ041-503-505-506-
508>511.
DISCUSSION...77
AVIATION...82
FIRE WEATHER...77
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