153
FXUS66 KSEW 060446
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
846 PM PST Thu Nov 5 2026
.UPDATE...
No changes made in the inherited forecast. We`re currently in a
lull before the next system offshore arrives later this evening
into early Friday morning with widespread rain and gusty winds.
Wind advisories are still on track to go into effect for the
coast, Whidbey & San Juan Islands along with the Northern
Interior late overnight. Wind gusts upwards of 50 mph are
possible during this time. Overnight lows are forecast to bottom
out into the 40s. The previous discussion remains below along
with an updated aviation section.
&&
.SYNOPSIS...
A strong frontal system will bring gusty winds and
additional rainfall to western Washington tonight and Friday. A warm
front will boost temperatures as it moves northwards into the area
Saturday. A follow-up cold front Saturday night into Sunday will
bring another round of rain and gusty winds. The weather pattern
remains active into at least the first half of next week.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
Current satellite imagery shows typical autumn cloudy skies over W
WA in advance of the incoming frontal system. Radar is starting to
clearly show the leading edge of this system over the outer coastal
waters.
A weak shortwave ridge will hold that system at bay briefly, keeping
conditions dry for much of W WA this afternoon and into the early
evening before rain moves in tonight. Gusty winds will accompany the
incoming front with particular concern for higher wind speeds along
the coast and the NW Interior /including the islands as well as
portions of western Whatcom and Skagit counties/...where speeds
could get as high as 20-30 mph with gusts to 50 mph. Models have
remained consistent with these speeds and as such, inherited Wind
Advisory for the aforementioned areas remains on track. As this
system mainly impacts the area through the day Friday, this is when
the bulk of the rainfall is expected with amounts ranging one-half
to three-quarters of an inch on the high end...mainly expected over
the higher terrain and along the coast...to one tenth to one quarter
of an inch most remaining lowland locations. Snow levels will rise
throughout the event, starting the day off at around 5000-6000 ft
and lifting to around 9000 in the afternoon. As such, not much of a
concern for high elevation snowfall at this time.
The front pushes out of the area very late Friday night, allowing
for another weak, short-lived shortwave ridge to enter the area.
This feature will not be terribly effective at dispelling clouds nor
lingering post-frontal showers, but does provide a relative lull in
activity for much of Saturday before the next frontal system comes
knocking on the coastline come Saturday night. Another round of
strong winds will accompany this front as it moves through during
the overnight hours, with wind impacts being felt over much of the
CWA. While the more wind prone locations along the coast, the
islands and the NW interior will likely see headline conditions, it
is entirely possible that other locations along the Sound may see
speeds high enough to qualify. It is a little too far out to make
decisions on headlines just yet, but situation is being monitored.
Even though the short term will be active, temperatures are expected
to remain mild with daytime highs still a few degrees above seasonal
normals. Saturday will actually see a boost in temperatures with
daytime highs that day getting into the 60s for most lowland
locations. Overnight clouds will keep lows from sinking too much,
mostly ranging from the mid 40s to around 50 for the entire short
term period.
18
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
Winds ease quickly Sunday with most breezy conditions wrapping up by
mid-morning. Frontal passage throughout the day will drag its feet a
bit, but a follow-up shortwave ridge should begin to impact the area
Sunday night into Monday. This break in the action continues until
Monday afternoon, when the next frontal system will begin to enter
the area. By this point, snow levels will have fallen to around 4000-
5000 ft, but are quick to rebound late Monday to above 6000 ft. The
frontal passage late Monday will extend into Tuesday with another
potential break possible Wednesday as upper level ridging builds
over the Rockies. Models fall into disagreement here as the westward
extent of the ridge is a point of contention. The operational
deterministic models show the split well, with the ECMWF keeping the
ridge east enough where rain could get at least as far east as the
Olympic Peninsula while the GFS shows the ridge west enough to keep
any systems off the coast. Ensembles show a wide array of solutions,
however the mean does trend slightly drier...leaning more toward the
ECMWF and perhaps even dragging precip slightly further east. The
NBM falls in line with this latter thinking and is a good starting
point for the forecast this far out. Neither daytime highs nor
overnight lows stray too much from the temperature pattern
established during the short term.
18
&&
.AVIATION...
Generally VFR across western Washington terminals this evening, with
areas of MVFR ceilings along the Pacific Coast as a frontal system
with rain approaches the coast. An OVC100 ceiling across the region
will gradually lower tonight as a frontal system pushes through the
area, trending towards low end VFR to MVFR, with potential for lower
IFR conditions in heavier rain. Rain will start moving in along the
coast around 06Z and fill into the interior terminals after 10Z
tonight. Additionally, gusty winds will develop tonight into Friday,
mainly along the coast and north of PAE, where sustained wind speeds
of 15-25 kt with gusts toward 30-40 kt are possible after 09z Fri.
Southeasterly winds will also become breezy elsewhere, with gusts up
to 20-30 kt through Friday afternoon.
KSEA...VFR this evening with mid to high clouds gradually lowering
early Friday morning closer to low end VFR/MVFR as a frontal system
moves inland. Rain will spread over the terminal in the early
morning Friday, likely bringing MVFR conditions after 09z Fri. SE
winds around 5-10 kt, with gusts up to 20 kt possible during the day
Friday.
29/15
&&
.MARINE...
An active weather patter across area waters will continue into next
week as a series of frontal systems cross the region. These frontal
systems will bring both the combination of seas and winds. The next
frontal system will impact the waters tonight into Friday, bringing
elevated seas around 14-20 ft and gale force winds across the
coastal waters and portions of the interior waters. Additionally,
there is a slight chance (15-20%) for storm force winds at times for
the coastal waters, East Strait, and Northern Inland Waters. A
stronger system will arrive this weekend for elevated seas and
possible widespread gale force winds. Models are hinting at a 30-40%
chance for storm force gusts over the coastal waters and Strait on
Saturday afternoon and a 20% chance for for Admiralty Inlet,
Northern Inland Waters, and Puget Sound. Additionally, models
continue to be consistent with the chances for seas above 20 feet by
early Sunday morning. Brief high pressure will build over the waters
Sunday night into early Monday. Multiple systems will move over the
waters next week, with the continued potential for additional
headlines.
A period of strong afternoon ebbs are expected for Grays Harbor Bar
starting Friday, which could coincide with with a rough to severe
bar at times.
29
&&
.HYDROLOGY...
River flooding is not expected through the next
seven days. However, a series of increasingly wet weather
systems will bring rain (and high mountain snow) to the region,
especially from Friday onward. While current forecasts are not
expected to cause flooding, this will begin to saturate soils
and raise base flows that could bring a concern with subsequent
storms systems into next week.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Wind Advisory from 4 AM to 4 PM PST Friday for Island County-
Lowlands of Western Skagit and Northwestern Snohomish
Counties-Lowlands of Western Whatcom County-San Juan
County.
Wind Advisory from 1 AM to 1 PM PST Friday for Northern
Washington Coast.
Wind Advisory from 7 AM to 4 PM PST Friday for Grays Harbor
County Coast.
PZ...Small Craft Advisory until 7 AM PST Saturday for Grays Harbor
Bar.
Gale Warning until 2 PM PST Friday for West Entrance U.S.
Waters Strait Of Juan De Fuca.
Gale Warning until 2 PM PST Friday for East Entrance U.S.
Waters Strait Of Juan De Fuca.
Gale Warning from 2 AM to 2 PM PST Friday for Northern Inland
Waters Including The San Juan Islands.
Small Craft Advisory until 4 PM PST Friday for Admiralty Inlet.
Small Craft Advisory until 10 PM PST this evening for Coastal
Waters From Cape Flattery To James Island 10 To 60 Nm-
Coastal Waters From Cape Flattery To James Island Out 10
Nm-Coastal Waters From James Island To Point Grenville 10
To 60 Nm-Coastal Waters From James Island To Point
Grenville Out 10 Nm-Coastal Waters From Point Grenville
To Cape Shoalwater 10 To 60 Nm-Coastal Waters From Point
Grenville To Cape Shoalwater Out 10 Nm.
Gale Warning until 4 PM PST Friday for Coastal Waters From
Cape Flattery To James Island 10 To 60 Nm-Coastal Waters
From Cape Flattery To James Island Out 10 Nm-Coastal
Waters From James Island To Point Grenville 10 To 60 Nm-
Coastal Waters From James Island To Point Grenville Out
10 Nm-Coastal Waters From Point Grenville To Cape
Shoalwater 10 To 60 Nm-Coastal Waters From Point
Grenville To Cape Shoalwater Out 10 Nm.
&&
$$
NWS SEW Office Area Forecast Discussion