168
FXUS66 KPQR 151155
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
355 AM PST Sat Nov 15 2025

.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 Tonight...The latest water vapor
satellite imagery features a prominent cutoff upper low centered
off the California coast while nearly zonal flow continues
overhead locally. Over the next 24 hours, upper-level ridging
will begin to build east of the Cascades, continuing to shift
eastward in tandem with the closed low slowly meandering inland
over California and Nevada. As ridging amplifies inland,
lingering light rain showers will continue to dissipate, with
the northern Oregon coast and Coast Range, southern Washington
coast, Willapa Hills, and the northern Oregon and southern
Washington Cascades remaining the most likely to see drizzle or
a brief rain shower through midday. Otherwise, dry conditions
are favored through tonight with overcast skies trending
clearer, especially from the southern Willamette Valley north
and west across the Cascades and Cascade foothills up to the
Columbia Gorge through this afternoon. Areas which see morning
rain and where sufficient clearing develops may be prone to
patchy fog overnight, most likely within sheltered Coast Range
valleys. Expect above-normal temperatures in the mid 50s to low
60s today and overnight lows largely in the 40s tonight. -36


.LONG TERM...Sunday through Friday...As upper-level ridging
pushes farther to the east through the middle of next week, a
progressive and active pattern takes hold in the Northwest. An
initial deep but narrow trough will approach the coast Sunday
into Monday, bringing a return of widespread rainfall chances to
the region by Sunday afternoon. There remains some uncertainty
around the evolution of this trough; the majority of global
ensemble members depict its development similar to the current
pattern, namely the flow may pinch the bottom of the trough into
a cutoff low affecting California while the energy associated
with the remaining weakened rump trough moves into the Pacific
Northwest, or the minority of members suggest it could maintain
a more coherent single elongated trough structure. Ultimately,
the precipitation forecast may be the most sensitive to the
details of the flow evolution, but both scenarios end with much
cooler air aloft advecting into the region by Monday.

With cooler air in place, temperatures will drop toward more
seasonable values during the workweek with daytime highs in the
upper 40s to mid 50s and overnight lows in the mid 30s to low
40s. As showers continue while troughing exits eastward through
Tuesday night, snow levels dropping to 3500-4500 ft could see
light accumulations at pass-level in the Cascades where
snowfall amounts remain very light through Tuesday. With less
than a 10% chance of more impactful amounts near 6 inches at
area passes, only minimal travel impacts are anticipated.

Following a brief dry stretch on Wednesday as narrow upper-level
ridging transits the region, another cutoff low along the coast
could see additional precipitation chances from Wednesday night
through Thursday night. Snow levels remaining around 4000-4500
ft could again see pass-level accumulations, although the
chances of 6 inches from 4 AM Wednesday through 4 AM Friday at
area passes remain only 10-20%. -36

&&

.AVIATION...VFR/MVFR flying conditions continue inland while IFR
conditions prevail at coastal terminals early this morning.
Drizzle or light rain showers will maintain restricted vis along
the coast through 16-18z Sat before improving, while there is
60-70% confidence that cigs remain at IFR levels. The best chances
for sufficient clearing to yield MVFR cigs are at KONP, with lower
chances to the north. South winds this morning will ease to around
5 kt, then turn out of the north to northeast by this evening.

Inland, cigs are expected to continue trending down to widespread
MVFR by 15-16z Sat. Brief vis restrictions are possible within
showers, but confidence in shower timing is too low to include in
TAFs. The exception will be in the southern Willamette Valley
including at KEUG, where VFR conditions are more likely to prevail
through today as skies clear from the southeast. By tonight,
patchy fog/mist may develop inland, most likely at KEUG thanks to
earlier clearing, with lower odds to the north where skies
remained cloudier. South to southeast winds at 5-10 kt early this
morning will become calm to light and variable by this evening.

KPDX AND APPROACHES...MVFR cigs expected to prevail through
tonight with intermittent light rain showers. Brief vis
restrictions are possible as showers move over the terminal, but
confidence in timing is too low to include in TAF and the
duration of any restrictions is likely to be short. Otherwise,
conditions trend drier after 21z Sat with cigs lifting to low-end
VFR at around 4 kft. Southeast winds at 5-10 kt this morning will
ease below 5 kt by this afternoon, and turn out of the north to
northwest this evening. Chances for further vis restrictions
within fog/mist increase after 06z Sun. -36

&&

.MARINE...Seas are expected to persist at 6-8 ft through the
weekend while southerly winds ease below 10 kt by this
afternoon. Another frontal system traverses the waters Sunday
into Monday, bringing increased southwesterly winds with gusts
to 20 kt before turning out of the northwest. Behind the front,
a building westerly swell will increase wave heights to 13-15 ft
by Monday morning, before falling below 10 ft again on Tuesday.
Should this forecast remain on track, an additional round of
Small Craft Advisories will be needed across the waters for this
event. Expect a fairly active weather pattern to continue
through the rest of the week as yet another system may bring
hazardous winds and seas later in the week, with increasing
chances for seas at or above 15 ft Thursday into Friday. -36/99

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...None.
WA...None.
PZ...None.

&&

$$

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