393
FXUS66 KPDT 151723
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
1023 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 /18Z TAFS THROUGH 18Z SATURDAY/
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. WIND GUSTS,
MAINLY IN THE 25 TO 30 KT RANGE WILL CONTINUE THROUGH EVENING,
THEN SUBSIDE TO 10 KTS OR LESS. WIND GUSTS IN THE 20 TO 25 KT
RANGE ARE EXPECTED ON SATURDAY, AND SHOULD START TO INCREASE
DURING THE MORNING HOURS.
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 37 / 0 10 20 30
ALW 63 43 58 40 / 0 30 60 50
PSC 67 41 65 38 / 0 10 20 20
YKM 64 37 64 37 / 0 10 10 0
HRI 65 39 63 37 / 0 10 10 10
ELN 56 32 56 34 / 20 40 10 10
RDM 65 31 54 26 / 0 10 10 10
LGD 63 37 51 34 / 0 40 60 50
GCD 66 36 52 32 / 0 10 30 50
DLS 64 43 60 40 / 0 70 30 20
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...NONE.
DISCUSSION...71
AVIATION...77
FIRE WEATHER...71
HYDROLOGY...71
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page