316
FXUS66 KPQR 281145
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
345 AM PST Fri Nov 28 2025

.SYNOPSIS...Showers taper off through the morning today,
becoming dry by this evening. Gusty east winds expected through
the western Columbia River Gorge and over the Cascades and north
Oregon Coast Range tonight into Saturday morning. A weak
shortwave Saturday brings slight chances for rain Saturday,
mainly for the terrain. Cooler low temperatures Sunday and
Monday before another weak shortwave returns slight rain chances
Tuesday. Dry weather returns Wednesday with cooler morning
temperatures Wednesday and Thursday mornings.

&&

.DISCUSSION...Friday Morning through Thursday...Early Friday
morning, surface observations indicate the low pressure system
that approached the coast last night has stalled along the far
northern Oregon coast, just south of the Washington border. It
has slowly weakened overnight and will continue to weaken as it
slowly moves south along the northern Oregon border Friday
morning before retrograding to the west back into the eastern
Pacific off of the coast of the Tillamook area. Wind gusts
peaked before midnight around 35-45 mph for the inland lowlands
north of Salem and 40-50 mph along the coast and Cascades with
isolated gusts to 50-60 mph on the wind prone beaches and
headlands along the coast. Winds are decreasing early this
morning and should be below 20 mph for most locations except for
the high Cascades by 6-8 AM. Additionally, the band of moderate
to heavy rain that moved through last night is now over the
Cascades with light showers or drizzle to the west of the
Cascades. This showers will mostly dissipate through the morning
hours with widespread dry conditions by this evening.

Weak high pressure builds over the area tonight into early
Saturday with model guidance indicating surface pressure
gradients tightening over the Cascades as a surface low digs
south into Montana and Wyoming. CAMs indicate the pressure
gradient from PDX to DLS could tighten to -5 to -7 mb late
tonight through Saturday morning, which would allow breezy east
winds to develop over the Cascades, north Oregon Coast Range,
and through the western Columbia River Gorge. REFS and HREF
suggest peak wind gusts of 30-35 mph over the terrain and
through Cascade gaps, 35-45 mph through the western Columbia
River Gorge, and 25-30 mph into Troutdale and the eastern
Portland metro area. Additionally, NBM does indicate a 10-20%
chance of gusts up to 50-60 mph in the windiest areas around the
Columbia River Gorge, such as in the south Washington Cascades
at Three Corner Rock and Larch Mountain.

An upper shortwave and associated surface front are slated to
move south from western Canada into Washington and Oregon
Saturday into early Sunday, which will break down the tight
surface pressure gradients and allow east winds to weaken by
Saturday afternoon. This weak system will bring a slight chance
of showers to the area, first to the coast and high elevations
in the afternoon, spreading to the interior valleys by the
evening, with dry conditions returning by Sunday morning.
Limited precipitation is expected with this system, with amounts
mainly less than 0.1 inch over the Cascades and more of a
drizzle or light rain elsewhere. Colder arctic air will
infiltrate the region first with the building high pressure and
additionally with this weak weather system. This will allow snow
levels to fall to pass level Saturday afternoon and down to
1500-2500 ft in the far north Oregon Cascades and SW Washington
Cascades and to 3500-4500 ft in the central Oregon Cascades.
However, with overall precipitation expected to be limited, so
will any snow that does develop. Expecting less than 1-2 inches
at the high Cascades with mainly snow falling and not sticking
to roadways at or below pass level.

The cold air funneling into the area behind the shortwave will
allow for colder overnight and morning temperatures Sunday
morning and Monday morning. Sunday morning, expect widespread
low temperatures in the mid to upper 30s across the interior
lowlands with only colder pockets outside of urban areas nearing
freezing. Monday morning is still expected to be the coldest
morning with a 60-80% chance of lowland locations outside of
urban areas to fall below freezing. In urban areas such as Salem
and Eugene, probabilities fall to 30-45%, and to 5-15% for the
Portland metro area and downtown Vancouver. The outskirts of the
Vancouver metro area, around and north of Highway 500 and east
of Interstate 205, probabilities increase rapidly to 40-60%.
Daytime temperatures on Sunday will be on the cooler side, as
well, with interior lowlands struggling to reach 50 degrees and
30s to 40s in the Cascades. Daytime temperatures warm slightly
on Monday as high pressure builds over the region, though
mainly for the Cascades.

Ensemble guidance is in good agreement that the high pressure
won`t last long as another weak shortwave will move through the
region from the north on Tuesday. This will bring another round
of shower chances with limited precipitation accumulation but
also warmer temperatures due to increased cloud cover. At this
point, ensembles indicate this shortwave won`t be as deep or
track as far west as the Saturday wave, and as such it won`t
bring as much cooler air into the region. Still, ensembles are
in very good agreement that upper level ridging is once again
slated to build over the PacNW Wednesday into Thursday, bringing
dry conditions and likely clear skies. These clear skies will
allow for radiative cooling in the overnight and morning hours,
so morning low temperatures Wednesday and Thursday could once
again fall into the 30s Wednesday and Thursday morning. -03

&&

.AVIATION...Light scattered rain showers or drizzle will continue
through the region Friday morning, dissipating by 19-21z Fri at
most terminals, though the north Oregon and south Washington
coast are already dry. Widespread MVFR cigs and vis expected to
continue at all inland terminals into the afternoon, dissipating
from south to north between 21z Fri and 00z Sat. Occasional
periods of IFR conditions possible, mainly at KHIO or KUAO. Along
the coast, conditions range from MVFR cigs and vis at northern
terminals to IFR/LIFR conditions along the central Oregon coast.
Conditions expected improve to VFR from north to south through
the day. KAST should improve to VFR by 13-15z Fri, but the rest of
the terminals could hold onto lowered flight conditions until 21z
Fri to 00z Sat.

Elevated southerly winds inland will continue to decrease over the
next few hours and expected to be below 10 kts everywhere by 15z
Fri. Winds along the coast are already less than 10 kts, becoming
east to southeast through the day. Offshore flow increases tonight
with inland winds shifting north to east and coastal winds
shifting due east. East winds increase along the Cascades and
through the western Columbia River Gorge after 03z Sat with gusts
up to 35-45 kts through the mouth of the Gorge. Gusts up to 25-30
kts could push west to KTTD and 20-25 kts to KPDX.

KPDX AND APPROACHES...Predominately MVFR conditions through the
afternoon with flight levels around 11kt-25kft. Conditions
expected to begin improving to VFR between 22z Fri to 00z Sat,
remaining VFR through the rest of the TAF period. South winds with
gusts to 25 kts continue through 13-15z Fri, quickly decreasing to
less than 10 kts after and becoming southeast. Winds shift
easterly after 00z Sat then increase after 05-07z Sat with gusts
up to 25 kts, not expected to decrease until after 15z Sat. -03

&&

.MARINE...A low pressure system has stalled just south of the
mouth of the Columbia River overnight Thursday night and has
begun to weaken. It will continue to weaken through Friday,
slowly moving south along the north Oregon coast in the morning
before retrograding and moving west out into the eastern Pacific
through zones PZZ252 and PZZ272 in the afternoon. Expect variable
winds through the morning, turning east to southeast in the
afternoon in the wake of the low. Winds have been decreasing
overnight and are expected to be below 20 kts by 4 AM PST Friday.
Additionally, seas have fallen to the low teens, and are expected
to remain around 9-11 feet at 11-12 seconds through the morning
hours. A Small Craft Advisory for elevated seas will continue
through 10 AM PST Friday.

Offshore flow will continue through Saturday with winds generally
at 10 kt or less, although areas downstream of gaps in coastal
terrain may see locally stronger east winds. As high pressure
builds Sunday into early next week, winds will shift north to
northwest at 10-15 kt. Seas will fall to 5-8 ft by Saturday and
will continue through next week. -03

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

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

$$

www.weather.gov/portland

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