026
FXUS66 KPDT 151032
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
332 AM PDT FRI MAY 15 2026
KEY MESSAGES
- MINIMAL PRECIPITATION IMPACTS
- MOUNTAIN THUNDERSTORM RISK ON SATURDAY
- MIDWEEK WARMING
DISCUSSION
ZONAL WESTERLY MID LEVEL FLOW ACROSS THE PAC NW WILL BREAK DOWN
INTO A LOW AMPLITUDE TROUGH BY THE OVERNIGHT AS A SHORTWAVE
OVER THE GULF OF ALASKA SWINGS RAPIDLY SOUTHEAST TODAY. THIS
WILL CAUSE LIGHT WINDS THIS MORNING TO STEADILY INCREASE INTO
THE AFTERNOON BECOMING WESTERLY AT AROUND 15 TO 20 MPH AND
GUSTING TO AROUND 30 MPH ACROSS THE BASIN AND CENTRAL OREGON AND
EVEN TO AROUND 40 TO 50 MPH ACROSS THE SIMCOE HIGHLANDS.
AFTERNOON TEMPERATURES WILL RANGE FROM ONLY 30S AND 40S IN THE
MOUNTAIN ZONES, 50S ACROSS THE BLUE MOUNTAIN FOOTHILLS AND AS
WARM AS 70 DEGREES IN THE JOHN DAY BASIN THIS AFTERNOON.
MOUNTAINS ZONE THUNDERSTORMS CAN DEVELOP DUE TO THE COLD AIR
ALOFT MOVING IN AND DESTABILIZING THE COLUMN IN COMBINATION WITH
WESTERLY FLOW/OROGRAPHIC LIFT. HREF MEMBERS SHOW 10-50% CHANCES
FOR THUNDERSTORMS/LIGHTNING RAMPING UP AROUND NOON ON SATURDAY
AND LINGERING THROUGH THE DAY.
THE LOW AMPLITUDE TROUGH WILL TRANSITION TO NORTHWEST FLOW
EARLY NEXT WEEK CREATING A SUBSIDENT SETUP FOR BROAD SUBSIDENCE
AND LIGHT WESTERLY WINDS, INCREASING TEMPERATURES AND DRY
CONDITIONS THROUGH THE BALANCE OF THE WEEK.
AVIATION /12Z TAFS THROUGH 12Z SATURDAY/
LIGHT WIND THIS MORNING WILL BE INCREASING BY LATE MORNING INTO
THE AFTERNOON TO 15 TO 20 KNOTS AND GUSTING TO AROUND 25 AND 30
KNOTS. INCREASING CLOUDS ARE ANTICIPATED TO REMAIN ABOVE 5,000
FT FOR THE ENTIRE FORECAST PERIOD.
FIRE WEATHER
OVERALL FIRE WEATHER RISK DUE TO COMBINED LOW RH AND STRONG
WINDS IS LIMITED OVER THE NEXT 7 DAYS. DRY LIGHTNING REMAINS A
RISK ON SATURDAY OVER THE MOUNTAINS REGION AS THE ADVECTION OF
COLDER AIR ALOFT INCREASES INSTABILITY.
HYDROLOGY
THE NACHES RIVER WILL BE FALLING BELOW THE ACTION STAGE OF 16
FEET LATER THIS MORNING.
PRELIMINARY POINT TEMPS/POPS
PDT 63 40 59 38 / 0 10 20 30
ALW 63 43 59 40 / 0 20 60 60
PSC 67 41 65 38 / 0 10 20 10
YKM 64 38 63 38 / 0 10 10 0
HRI 65 40 63 37 / 0 10 10 10
ELN 56 32 55 34 / 20 30 10 0
RDM 65 32 53 26 / 0 10 10 10
LGD 63 38 52 34 / 0 30 70 60
GCD 66 36 53 32 / 0 10 30 60
DLS 64 43 61 41 / 0 70 30 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...NONE.
DISCUSSION...71
AVIATION...71
FIRE WEATHER...71
HYDROLOGY...71
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