529
FXUS66 KPQR 081108
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
308 AM PST Sat Nov 8 2025

.SYNOPSIS...Patchy dense fog and low stratus across the
Willamette Valley will result in visibilities as low as 0.25
mile in some areas. Be cautious if commuting through fog this
morning. Dry weather returns this weekend as high pressure
builds over the Pacific Northwest. Offshore flow will also
increase, with breezy easterly winds through the Columbia River
Gorge and eastern Portland/Vancouver Metro. A weak shortwave
trough will return chances for light rain on Monday, with
another potential system mid-to-late next week.

&&

.DISCUSSION...Tonight through Friday night...Satellite imagery
and surface observations as of early Saturday morning depicts
low stratus and fog developing across the Willamette Valley and
southwest Washington lowlands. Dense fog has been patchy so far
across these areas, with visibilities bouncing between 0.25
mile and 1.5 mile. Since fog with visibility of 0.25 mile or
less has not been very widespread or long-lasting, have decided
not to issue a Dense Fog Advisory for now. Will continue to
monitor over the next few hours to see if that changes. If you
will be commuting this morning, make sure to slow down, leave
plenty of space between you and other vehicles, and use your low
beam headlights.

An upper level ridge will continue to build over the Pacific
Northwest this weekend bringing a return to drier conditions.
Should see increasing sunny skies by the afternoon with
afternoon high temperatures likely warming into the lower 60s.
An offshore pressure gradient will also gradually increase
easterly winds today, especially through the Columbia River
Gorge and eastern Portland/Vancouver Metro Area. Latest guidance
suggests the gradient from KTTD to KDLS peaks around -6 to -7
mb Saturday night into early Sunday morning, suggesting wind
gusts up to 30-40 mph for the far eastern Portland/Vancouver
Metro (Troutdale/Camas), and up to 60 mph for exposed ridgetops
(e.g. Crown Point and Three Corner Rock). Offshore flow could
make temperatures at the coast a degree or two warmer than the
Willamette Valley this weekend. Slightly warmer conditions
expected on Sunday as the ridge of high pressure amplifies into
western Canada and persists over the region, shifting slightly
eastward over the Great Basin.

Sunday night into Monday, the upper ridge begins to flatten as a
shortwave trough pushes into British Columbia and NW Washington.
Since most ensemble guidance suggest that this system will
track further north of our area, precipitation amounts are not
looking significant or impactful. The highest chances for rain
are along the coast and southwest Washington (60-80%), while
chances for rain are lower (20-40%) across interior northwest
Oregon. While the majority of ensemble guidance (75%) suggests
rain arrives sometime late Sunday night into Monday, 25% of
members do suggest rain arrives as early as Sunday afternoon
along the coast. Chances for 0.25" of rain or more in a 24 hr
period from 10 PM Sun to 10 PM Mon are only 20-40% along the
coast (highest chances Tillamook northward) and 5-15% across
the Willamette Valley and southwest Washington lowlands.

Another upper level ridge builds over the Pacific Northwest on
Tuesday, bringing a brief return of dry weather. By Wednesday,
this ridge quickly gets pushed eastward as another low pressure
system over the NE Pacific progresses toward the Pacific
Northwest. The majority of ensemble members (>80%) are in
general agreement of light rain returning by Wednesday night as
the cold front associated with the low swings through. Rain
continues into Thursday, though there still remains some
uncertainty with exact precipitation amounts and timing. For
now, chances for 48 hour rain totals from 4 AM Wednesday to 4 AM
Friday are around 60-80% along the coast, Coast Range, and
Cascades, while chances are around 15-25% across interior
lowland valleys.      -10

&&

.AVIATION...Satellite imagery and terminal observations as of
early Saturday morning depicts areas of LIFR/IFR VIS and CIGs
across the Willamette Valley as patchy dense fog and low stratus
begins to develop. Expect this mix of fog and low stratus to
continue through 18z Sat with LIFR/IFR thresholds across most
Valley terminals. An exception would be the far eastern Portland
Metro including KTTD where easterly winds through the Columbia
River Gorge would keep conditions more clear (less than 5%
chance for fog). If easterly winds end up stronger, then KPDX
could end up clearing as well. For now, not expecting easterly
winds to be strong enough to clear out KPDX. An offshore
pressure gradient will also bring easterly winds to the coast,
keeping KAST and KONP predominately VFR through the TAF period.

Any fog or low stratus that develops this morning should begin
to lift by 17-19z Sat as daytime heating progresses. VFR
conditions return to the Willamette Valley by the afternoon with
FEW/SCT high clouds as high pressure builds over the region.
Winds generally easterly to northeasterly, breeziest in the east
Portland Metro with gusts up to 25-30 kt this afternoon.

KPDX AND APPROACHES...LIFR VIS/CIGs continue through 17-18z Sat
as clear skies and light winds support patchy dense fog and low
stratus development. Winds remain light and northerly early this
morning, turning more easterly around 17-18z Sat. These winds
will help clear out KPDX. Easterly winds gradually increase
into the afternoon around 10-15 kt with gusts up to 20 kt. VFR
conditions continue through the rest of the TAF period.    -10

&&

.MARINE...A Small Craft Advisory continues across the waters
through 10 AM Saturday morning as buoy observations as of early
Saturday morning show seas around 12-13 ft at 11 sec. After 10
AM today, the westerly swell should ease below 10 ft. Another
Small Craft Advisory has been issued for the Columbia River Bar
today from 4-9 PM due to a very strong ebb resulting in seas of
7-9 ft at 12 sec.

High pressure building inland will drive offshore (easterly)
winds around 10 kt today before turning more southerly on Sunday
as a weak front approaches the coast. Winds should remain
minimally impactful through the weekend, with the chances for
maximum gusts reaching 20 kt remaining below 5% south of Yaquina
Head, increasing to 25% at Cape Lookout, to 50% at the mouth of
the Columbia River, and further to 65% at the mouth of Willapa
Bay. Meanwhile, seas ease to 4-7 ft by Sunday morning.

Winds vary through the first half of next week, but look to
remain  at 5-10 kt through Wednesday morning, and 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 see increasing southerly winds
and a building southerly swell, increasing the chances for
another period of conditions hazardous to small craft late
Wednesday into Thursday. At this point, gale-force winds are not
favored during this period, with 30-50% chances of occurrence
beyond 20-30NM.        -10/36

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...None.
WA...None.
PZ...Small Craft Advisory until 10 AM PST this morning for PZZ210-
     251>253-271>273.

     Small Craft Advisory from 4 PM this afternoon to 9 PM PST this
     evening for PZZ210.
&&

$$

www.weather.gov/portland

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