773
FXUS66 KSEW 042327
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
327 PM PST Wed Nov 4 2026
.SYNOPSIS...A weak frontal system moves across the area through
tonight. A stronger system arrives Friday bringing steadier rain
and locally gusty winds. Warm front moves northwards on Saturday
with an associated cold front bringing another round of rain and
gusty winds late Saturday into Sunday. A brief break early
Monday before additional systems arrive into midweek.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...A front is
approaching the coast this afternoon with increasing mid and
high clouds over western Washington. The front moves onshore
late this afternoon and moves into Puget Sound this evening into
tonight. A few hours of steadier rain is expected with this
system. In addition, south winds will peak around 15 to 30 MPH
along the immediate coast and Whidbey Island region this
evening. Otherwise, this will be a weaker system with rainfall
amounts up to 0.15" for most of Puget Sound, and 0.25-0.5" along
the coast. Temperatures peak in the 50s today.
There will be a break in the precipitation on Thursday, with
even a mix of clouds and sunshine. However, the break will be
relatively short as the next frontal system approaches the
region Thursday night with increasing rain early Friday.
Steadier rain continues on Friday for most areas, with the
heaviest QPF amounts focused in the Cascades and Olympic
Peninsula. South winds also increase early Friday. Winds are
expected to be strongest along the northern coast and from
Whidbey Island northwards. NBM probabilities for gusts over 40
MPH range 50-90% for the majority of these areas, with higher
probabilities on the REFS. Will need to monitor the potential
for any Wind Advisory in these aforementioned regions on
Friday. Winds elsewhere will be locally breezy, with gusts
peaking between 20 to 30 MPH, especially near the water. The
front weakens Friday night, but a warm front lifts northwards
overnight, resulting in continued rain at times. Highs will
reach the 50s again Friday.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...The majority of
western Washington will be positioned in the warm sector on
Saturday as the warm front lifts into BC during the morning.
Most areas are expected to remain drier by Saturday afternoon,
with exception being the Olympic Peninsula and near the BC
border where there remains lingering precip potential.
Otherwise, highs will be warmer on Saturday, peaking in the 60s
for most areas.
A cold front progresses eastward Saturday night into Sunday
bringing additional steadier rain and gusty winds. The bulk of
the precip will be Saturday night, with precipitation more
confined to the Cascades by Sunday afternoon, other than a few
lingering showers. Another round of breezy south winds Saturday
night with the front, with the strongest winds again along the
coast and Whidbey Island northwards. However, winds will likely
be a bit stronger elsewhere with this front compared to Friday,
and thus more widespread gusts of 20 to 35 MPH may occur. In
addition, seas build to near 20 ft along the immediate coast on
Sunday, and will monitor for high surf conditions. Snow levels
initially around 8000 feet Saturday fall towards 4000-5000 feet
by later Sunday for higher elevation snow in the Cascades and
Olympics. A brief period of drier weather then arrives Sunday
night into Monday.
Uncertainty increases in ensembles later Monday into midweek.
However, there is potential for a longer duration rain event
during this period. Mean of ECMWF/CMC ensembles focus the
moisture plume towards western Washington, with GEFS focused
more into British Columbia. This will be something to monitor
over the next few days with additional rain, winds, and
increased waves likely at times next week. JD
&&
.AVIATION...Majority of terminals VFR this afternoon with high
clouds streaming overhead. Stubborn low clouds continue over
CLM, with some slow improvement to MVFR this evening. Ceilings
will deteriorate this evening for widespread MVFR conditions.
There is a slight chance (30- 40%) for IFR over the Kitsap
Peninsula and southern interior, and a 15-30% for LIFR. Rain
will start moving in along the coast this afternoon and fill in
to the interior terminals this evening. By early Thursday
morning, the rain will have pushed east into the Cascades.
Models hint at VFR conditions returning Thursday afternoon.
Breezy winds late this evening from south Puget Sound to the
northern interior, with gusts up to 20 kt possible between 04z-
09z as a front moves through the area.
KSEA...VFR conditions this afternoon will deteriorate this evening
to MVFR by 06Z. There is a slight chance (15%) for brief IFR
conditions between 14z-19z. Improvement to VFR by 20z. Rain expected
to reach he terminal after 00z today. SW winds today will transition
SE Thursday evening. Winds will briefly become breezy today between
06z-10z with the frontal passage.
&&
.MARINE...An active marine pattern will continue into next week
with multiple weather systems expected to move over area
waters. Increased south/southwesterly winds over the coastal
waters today will decrease as a cold front pushes inland later
today. Winds expected to also increase across the interior
waters with the passage of the front, with small craft
conditions expected for portions of the Strait of Juan de Fuca
and Admiralty Inlet. Winds will ease behind the front into early
Thursday.
A stronger system will move over the waters Thursday night into
Friday, bringing elevated winds and seas. Winds will increase area-
wide overnight. A Gale Watch has been issued for the coastal waters,
East Strait, and Northern Inland Waters due to increasing
probabilities for gale force winds gusts. Winds will ease towards
Friday evening. Seas will also increase Thursday night, climbing to
15-19 feet by Friday afternoon.
The weekend will remain active, with an even stronger frontal system
moving through the area. Widespread gale gusts are possible across
the waters Saturday afternoon through Sunday afternoon. The highest
chances for gales are for the coastal waters with a 60-85% chance,
while the interior waters have a 50-60% chance. Additionally, seas
will build through the day on Saturday and peak Sunday afternoon
towards 20 feet. There is a 40-50 chance for seas to exceed 20 feet.
Seas will start to ease late Sunday into Monday.
Conditions look to remain hazardous going into next week, as
additional frontal systems move near or through area waters. These
frontal systems will bring additional chances for strong to gale-
force winds.
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...None.
PZ...Small Craft Advisory until 1 AM PST Thursday for West Entrance
U.S. Waters Strait Of Juan De Fuca.
Small Craft Advisory from 4 PM this afternoon to 2 AM PST
Thursday for Admiralty Inlet-East Entrance U.S. Waters
Strait Of Juan De Fuca.
Small Craft Advisory until 10 PM PST this evening 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 until 10 PM PST this evening 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.
&&
$$
NWS SEW Office Area Forecast Discussion