754 
FXUS66 KPQR 091116
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
316 AM PST Sun Nov 9 2025

.SYNOPSIS...Dry weather continues today as high pressure
continues to build over the Pacific Northwest. Offshore flow
will peak this morning and gradually weaken throughout the day.
A weak shortwave trough will bring chances for light rain across 
the area tonight into Monday. High pressure re-builds on 
Tuesday, briefly returning dry weather. A stronger low pressure 
system arrives Wednesday, returning widespread rain. Snow levels
drop late in the week, returning chances for snow over the 
Cascade passes.

&&

.DISCUSSION...Today through Saturday night...An upper level
ridge will continue to amplify today, maintaining dry weather 
and slightly above normal high temperatures across northwest
Oregon and southwest Washington. Highs are forecast to peak in 
the low to mid 60s for most areas, except slightly cooler in the
Columbia River Gorge, south WA Cascades, and Upper Hood River
Valley as easterly winds continue to bring cooler air from
central/eastern Oregon.

The latest surface observations as of 3 AM Saturday show 
easterly wind gusts up to 30-35 mph in the far eastern
Portland/Vancouver Metro and up to 45-50 mph at exposed 
ridgetops (Three Corner Rock). Light easterly winds are also 
present along the coast. Pressure gradients from Troutdale to 
The Dalles (KTTD-KDLS) are peaking early Sunday morning around 
-6 to -7 mb and are expected to gradually ease today. As these 
pressure gradients ease, easterly winds will also weaken through
the Gorge and along the coast. Expect a transition to more 
southerly winds along the coast after 1-3 PM today.

Late tonight into Monday, the upper ridge begins to flatten as 
a shortwave trough pushes into southern British Columbia and far
northwest Washington. High-res ensemble guidance suggests that 
the front associated with this upper level shortwave will be 
very weak as it quickly brushes our area tonight. This scenario
would result in very light rain with low precipitation amounts.
There is high confidence (70-80% chance) that 24 hour rain 
amounts between 10 PM Sunday to 10 PM Monday remain less than 
0.10" for most places. Currently, the highest chances for rain 
are along the coast and southwest Washington (50-80%) as this 
weak front is tracking further north, while chances for rain are
lower (20-40%) across interior northwest Oregon. In terms of 
timing, light rain may arrive as early as this evening along 
the coast, spreading inland through Monday morning. Conditions 
gradually dry up Monday evening as the weak front progresses 
inland.

Tuesday, another shortwave upper level ridge builds over the 
Pacific Northwest and this will bring a brief return of dry 
weather. However, by Wednesday, this ridge quickly gets pushed 
eastward as a more robust low pressure system in the NE Pacific
takes aim at the Pacific Northwest. This stronger system will 
bring rain and cooler air back into the forecast. Current 
ensemble guidance has precipitation likely (70% chance) starting
Wednesday morning as the associated cold front moves in. Behind
the front, cooler air will settle in and bring snow levels down
to pass-level in the Cascades Thursday-Friday. Current guidance
suggests a 40-60% chance that 48-hour snow totals between 4 AM
Thursday to 4 AM Saturday exceed 6 inches through the passes,
with the highest chances at the Santiam and Willamette Passes.
An active weather pattern continues into the weekend.    -10

&&

.AVIATION...High pressure inland continues to support offshore 
flow and largely VFR conditions across the region. Gusts of
20-30  kt reach west of the Columbia Gorge to KPDX/KTTD and 
through other east-west oriented terrain gaps, but will trend 
downward this morning as the pressure gradient begins to weaken.
These east winds will inhibit any fog formation at both 
Portland-area terminals as well as along the coast. Across the 
central and southern Willamette Valley, there is a 20-30% chance
for IFR/LIFR VIS and CIGs due to potential fog/mist and low 
stratus development between 12-18z Sun. If northerly winds in 
these areas remain higher, a low stratus deck may be favored 
instead of surface-based fog. High cloud cover may also prevent
fog. Any fog and low stratus that develops this morning should 
clear out by 18-20z Sun as daytime heating progresses. 

CIGs begin to trend downward late in the TAF period as a weak 
frontal system approaches the coast, bringing a 60-80% chance
for IFR/MVFR CIGs along the coast after 06-09z Mon and chances
for light rain.

KPDX AND APPROACHES...VFR conditions expected through the TAF
period with SCT/BKN high clouds. Easterly winds around 5-10 kt, 
strongest this morning and gradually weakening.      -10/36

&&

.MARINE...High pressure inland will continue to drive offshore 
easterly winds, turning southerly to southeasterly on Sunday as
a weak front approaches the waters, decreasing to 8-12 kt as 
gap- flow easterly winds end. Seas will generally remain 6-9 ft 
at 10-12 seconds through Sunday.

Wind direction varies through the first half of next week, but
wind speeds look to remain at 5-10 kt through Wednesday morning. 
There is also high confidence (greater than 95% chance) that
seas  remain below 10 ft through midweek as well. An area of 
low pressure strengthening well offshore will return breezy 
southerly winds and building seas, increasing the chances 
(60-80% chance) for another period of conditions hazardous to 
small craft late Wednesday into Thursday. There is also a 30-60%
chance for Gale-force wind gusts greater than 34 kt during this
period, with the highest chances across the outer waters beyond
20-30 NM.        -10/36


&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...None.
WA...None.
PZ...Small Craft Advisory from 4 PM this afternoon to 10 PM PST this 
     evening for PZZ210.
&&

$$

www.weather.gov/portland

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