035
FXUS66 KPQR 160439 AAB
AFDPQR

Area Forecast Discussion...UPDATED
National Weather Service Portland OR
839 PM PST Sat Nov 15 2025

Updated Aviation and Marine Discussions

.SYNOPSIS...A relatively drier pattern with upper-level ridging
atop a closed upper low over California will give way to a
progressive and active pattern early next week. Repeated systems
will bring cooler temperatures along with multiple chances for
lowland rain and mountain snow to the region.

&&

.SHORT TERM...Now through Sunday night...Mostly dry conditions
are expected to persist until late tonight. A broad upper level
cut-off low continues to spin just off the central California
coast. Cloud cover across the region has started to dissipate
from southeast to northwest for much of Lane County and into the
Willamette Valley. This is due to the position of the upper low
bringing drier air from the Great Basin westward. Clearing is
expected to persist over the central and southern Willamette
Valley, eastward over the Cascades and south of the Columbia
River Gorge. Sufficient low level moisture in areas under clear
skies will have a decent chance of fog developing overnight,
mainly in the central and southern Willamette Valley. NBM
probabilities for visibility less than 3 miles peaks between
40-50% from Aurora southward overnight while probabilities for
less than 1 mile of visibility are between 20-30%. Elsewhere,
conditions are expected to remain mostly cloudy overnight.

The next round of rain is expected to reach the coast late
tonight into Sunday morning. A trough over the Gulf of Alaska
will dig southeast toward the PacNW, sending a cold front toward
the region. Rain is expected to move inland late Sunday
morning. The best moisture with this system splits the area,
with better moisture associated with the surface low that will
come onshore around Vancouver Island and another surface low
over southern Oregon and northern California. As such, rainfall
totals associated with this system are expected to be on the
lighter side generally 0.2-0.3 inches inland and 0.4-0.75 along
the coast and higher terrain. Minimum snow levels are expected
to remain above 4000-5000 feet with this system until the cold
front passes through and drops closer to 3000 feet. Not
expecting substantial snow at pass level with this system. /19

.LONG TERM...Monday through Saturday...The beginning of next
week remains active as the trough that brought Sunday`s rain
pinches of and develops into a cut-off low centered over the
Great Basin by late Monday. Residual moisture and the proximity
of the upper low is expected to support showery conditions.
Expect just rain below 3000 feet while some flakes may mix in
above this level in the Cascade Foothills and mainly snow on the
Cascade crest.

A brief period of dry conditions under shortwave ridging will keep
the latter half of Tuesday through Wednesday benign. The next
potentially impactful system is expected to impact the region
late Wednesday night into Thursday, though there is substantial
differences among the models and their ensembles. Cluster
analysis is split between solutions with around 35% showing a
weak trough, 34% showing a much deeper trough with an amplified
pattern, 16% close to zonal, and the last 15% with a deeper
trough but well offshore. Depending on what happens with this
late week system, could see impactful snow around the mountain
passes through, NBM spread is quite large with some showing no
snow and others showing 6 inches or more. Will need to keep an
eye on this system as it approaches late next week. /19

&&

.AVIATION...Generally VFR conditions across the airspace. However,
with ample clearing of lingering mid to high level cloud cover
underway, this will likely set the stage for widespread IFR/LIFR
conditions. Confidence in the timing of fog formation is still in
question, but onset of these lowered flight conditions will be
most likely around 07-09Z Sun for coastal locations and 10-12Z
Sunday for locations within the Willamette Valley.

Another frontal systems is expected to push inland Sunday along
with light rain beginning at the coast 17-19Z Sun before advancing
eastward into the Willamette Valley around 18-20Z Sun. This will
help to improve overall flight conditions towards MVFR across the
airspace through the remainder of the TAF period. Conditions are
likely to fall back towards IFR/LIFR along the coast after 00Z
Monday with inland locations maintaining MVFR conditions.

KPDX AND APPROACHES...VFR conditions to persist through around
10Z Sunday. Will have to be on the lookout for IFR/LIFR
conditions afterwards. If these flight conditions manifest,
expect them to persist through 18Z-20Z Sunday as conditions are
expected to improve towards MVFR, along with light
precipitation. /42

&&

.MARINE...Seas around 7 to 10 ft with a 10 to 12 seconds period
across all waters. Therefore, have issued a Small Craft Advisory
as seas are expected to remain elevated through at least Monday
evening. Another frontal system traverses the waters Sunday
evening into Monday, leading to increased southwesterly winds
initially, then quickly becoming northwesterly with gusts up to
25 kt, mainly for the outer waters. A building, fresh westerly
swell will continue to cause seas to build towards 12 to 15 ft by
late Sunday night/Monday morning, before falling below 10 ft
by early Tuesday morning. Wednesday into Thursday, another system
will bring about increasing winds and building seas across all
waters. Current guidance has low end Small Craft winds across all
waters, but a more robust swell is expected with this mid/late
week system. Models are showing a high probability of 15-17 ft
seas, but the 75th percentile is showing 20 ft seas with the 90th
percentile having 22 ft seas or higher. There is still some
uncertainty as the "worse case" scenario is currently showing 22
ft seas or higher. /42

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...None.
WA...None.
PZ...Small Craft Advisory until 7 PM PST Monday for PZZ210.

     Small Craft Advisory until 10 PM PST Monday for PZZ251>253-
     271>273.

&&

$$

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