700
FXUS66 KSEW 160429
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
829 PM PST Sat Nov 15 2025

.SYNOPSIS...
A stationary front will remain draped over western Washington
through the weekend, maintaining areas of showers and drizzle
at times through Monday. A trough and front will also pass
through Monday, with drier and cooler conditions behind the
front. More precipitation is expected towards the end of the
week.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
The latest forecast remains on track this evening as showers
taper off across western Washington, with no updates. Given the
abundance of low level moisture being trapped towards the
surface, expect areas of mist and patchy fog going into Sunday
morning (especially as shower activity diminishes from the
stationary front going into tonight).

Another trough/weak cold front will pass through the area Sunday
into Monday. This will increase shower chances going into the
morning/afternoon. High-resolution models have a few bands/lines
of rain moving through during the day (from the coast, inland
towards the Cascades). Rain rates with these bands are not
expected to exceed several hundredths of an inch an hour (couple
spots in the Cascades might see up to 0.10"/hr). The
precipitation chances will drop going into Monday (except for
the Cascades) as cold air begins to sink in behind the
trough/front. Expect snow levels to fall from 7,000-8,000 ft
this weekend down to below 4,000 ft by Monday night. Snow
accumulations will remain light at higher elevations with these
systems through the weekend (no snow accumulations are expected
at the passes). A couple locations in the south interior may see
lows dip below 40 Monday night/Tuesday morning.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
The trough from Monday is expected to dig southward into
Tuesday (with an upper level low eventually cutting off from the
main flow/trough system in British COlumbia). The ensembles now
favor a bit of a ridge going into Wednesday, which will favor
drier conditions going into Tuesday and Wednesday. This might
also allow for a few peaks of sun through the clouds during
these days as well. Another trough will spin through the region
the second half of the the week from an upper level low spinning
off the coast of B.C.. The forecasted precipitation dropped
considerably with this system (given that models are a bit more
split as to how strong/far the trough/low will dig over our
area). Nevertheless, the shower chances remain at 40-60% through
the end of the week, with the coast seeing up to an 80% chance
Wednesday afternoon. Temperatures will remain a touch cooler
with highs only reaching the upper 40s/low 50s, and lows dipping
into the upper 30s/low 40s.

HPR

&&

.AVIATION...
Westerly flow aloft becoming southwesterly tonight as upper level
trough digs south well offshore. Light flow in the lower levels
through Sunday afternoon with stationary front dissipating over the
interior overnight.

IFR/LIFR ceilings into Sunday afternoon. Areas of visibility 1-3SM
in light rain or drizzle. A weather system will bring another chance
of rain Sunday afternoon. Ceilings may improve slightly Sunday
evening, with some locations potentially improving to MVFR. However,
latest guidance suggests majority of terminals are likely to remain
IFR/LIFR.

KSEA...Currently VFR at the terminal but expecting ceilings to lower
later tonight after 06z to IFR/LIFR with visibility to 1-3SM due to
light rain or fog. Slight improvement Sunday afternoon/evening to
MVFR possible. Light winds around 3-5 kt.

Felton/29

&&

.MARINE...
A weak surface low will track across the offshore waters into
Northern Vancouver Island Sunday into Sunday night while an
associated front weakens and moves onshore Sunday evening. A surface
ridge will rebuild across the waters Monday into Tuesday before
shifting east of the area on Wednesday. A rapidly weakening frontal
system will reach the waters Wednesday night into Thursday.

Coastal seas will briefly build to 10 feet or higher Sunday
afternoon into Sunday night before subsiding again. Double digit
seas return late in the week as a result of a strong area of low
pressure around 140 W longitude.

27

&&

.HYDROLOGY...
The Snoqualmie at Carnation will crest around a foot short of flood
stage this evening. All other rivers will remain at or below
action stage. A weak front will produce non- hydrologically
significant rainfall late Sunday into Monday. Drier conditions
will return mid-week. Another weakening front will arrive late
Wednesday or Thursday, but is again not expected to produce
rainfall of any significance.

27

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory from 4 PM Sunday to 4 AM PST Monday for
     Coastal Waters From Cape Flattery To James Island Out 10
     Nm-Coastal Waters From James Island To Point Grenville
     Out 10 Nm-Coastal Waters From Point Grenville To Cape
     Shoalwater Out 10 Nm.

     Small Craft Advisory from 10 AM Sunday to 4 AM PST Monday for
     Coastal Waters From Cape Flattery To James Island 10 To
     60 Nm-Coastal Waters From James Island To Point Grenville
     10 To 60 Nm-Coastal Waters From Point Grenville To Cape
     Shoalwater 10 To 60 Nm.

&&

$$