Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
623
FXUS66 KSEW 080421
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
821 PM PST Sat Mar 7 2026
.SYNOPSIS...
A colder, wet,and windy pattern will prevail over the next 7
days. Several systems will bring an extended period of heavy
mountain snowfall, in particular through the middle of next
week. Monday and Tuesday will bring the chance for a rain/snow
mix in the lowlands and light accumulations in the foothills.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
As of this evening, radar imagery continues to show light
drizzle and showers across portions of Western Washington.
Otherwise, no major updates to the inherited forecast this
evening.
Light drizzle and showers will continue until a frontal system
moves in from the north and traverses the area Sunday morning.
This will mark the start of a much cooler and wetter pattern as
snow levels fall throughout the day. Snow levels will start at
around 5000 ft at present, down to around 1500-2500 ft by Sunday
afternoon/evening, then to around 500 ft by early Monday
morning. This will bring quick round of snowfall to the
mountains, particularly across the northern Cascades, for which
a Winter Weather Advisory is in effect. Precipitation will then
taper off for the afternoon/early evening hours except for the
development of a post-frontal convergence zone that will looks
to set up around Stevens Pass. Elsewhere, showers will return
across the area early Monday morning and look to continue
through Tuesday. With such low snow levels, a rain/snow mix will
be possible across the lowlands, as well as light accumulations
across the foothills. Daytime temperatures well above freezing
will help to limit and melt accumulations. All in all, snowfall
amounts in the mountains will be in the 6 to 12 inch range,
except up to 18 inches around Stevens Pass and through parts of
the North Cascades. 1-3 inches will be possible in the
foothills. No measurable snow is expected elsewhere.
Highs will be around 50 on Sunday, falling into mid 40s Monday
and Tuesday. Lows Sunday AM into the mid to upper 40s, falling
to mid to lower 30s Monday and Tuesday AM. Winds will also be
breezy throughout this time period, with gusts in the 20 to 30
mph range.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
The active pattern continues as a surge of increased moisture
reaches the area Tuesday night and continues through late
Thursday. Snow levels will bounce back up to around 2000 to 3000
ft through the long term period. This will be a longer period
of heavy snowfall across all area mountains. Several feet will
be likely by the end of the week. In addition to snow, windy
conditions are expected on Wednesday. The strongest wind gusts
will be along the Pacific coast and through the north interior.
Precipitation looks to begin to taper off Thursday into Friday
but the longer range models are hinting that the active pattern
will continue. Lastly, with the rising snow levels late week and
continued rain, the potential will increase for the Skokomish
river to rise into flood stage. See more details below in
hydrology. Temperatures look to remain fairly steady, with highs
in the upper 40s and lows in the mid 30s.
62
&&
.AVIATION...
Widespread MVFR ceilings this evening with a few areas
of IFR with stratus. MVFR cigs will continue for the interior
terminals through Sunday morning, with localized IFR at times.
Predominantly IFR with patchy LIFR along the coast. Steadier rain
will drift southwards t tonight through Sunday morning, which may
result in brief vsby reductions towards 4-6 statute miles during
this period. A convergence zone is expected to develop over northern
King Country and southern Snohomish County Sunday afternoon.
Improvement to widespread VFR Sunday afternoon. Increased south
winds through Sunday morning will transition to more northerly for
central Puget Sound in the vicinity of the convergence zone by late
morning. Winds expected to shift southerly again between 02z-05z.
KSEA...MVFR cigs will continue through Sunday morning. There remains
a low chance (around 20-25%) of IFR cigs tonight into Sunday
morning. Rain will increase around 12z as a front moves southwards,
with nearby showers after 18z. Improvement expected Sunday afternoon
into VFR after 22Z, although there remains a small chance (20-30%)
of MVFR cigs lingering into the afternoon. A brief period of MVFR
cigs possible 5z-10z. South winds will remain elevated into Sunday
morning, with gusts peaking around 25 kt. Winds expected to
transition to more N/NE between 17z-20Z as a convergence zone
develops in the vicinity of the terminal. Winds expected to shift SE
between 02z-04z. JD/29
&&
.MARINE...
Onshore flow will continue through tonight, with
flow being further enhanced into Sunday as a weather system
moves across the waters. Small Craft Advisories have been issued
for the northern inland waters due to increased south to
southwest winds through tonight. West winds will also increase
through the Strait of Juan de Fuca tonight and continue through
Sunday night, resulting in SCA wind gusts. Southwest winds will
also remain breezy for Puget Sound through Sunday morning, with
the strongest winds in the vicinity of West Point. Winds will
ease a bit Monday into Tuesday, but remain elevated,
particularly through the Strait of Juan de Fuca. South to
southwest winds will increase again on Wednesday ahead of a
stronger weather system. Additional headlines are likely
Wednesday into Thursday, with the potential for gales,
especially for the Coastal Waters, eastern Strait of Juan de
Fuca, Admiralty Inlet, and northern inland waters. Onshore flow
will then continue late week.
Seas will build to 8 to 10 feet tonight into Sunday, with 10 ft seas
mainly over the central and northern outer Coastal Waters. Seas then
build further for all Coastal Waters to 10 to 12 feet Monday and
Tuesday, and build towards 15 ft by midweek. JD
&&
.HYDROLOGY...
Heavy precipitation over the Olympics, combined at times with
snow levels rising will force rises on the Skokomish River with
the potential for flooding late next week. No other river
flooding is expected during the next seven days.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Winter Weather Advisory from 5 AM to 1 PM PST Sunday for
Cascades of Snohomish and Northern King Counties-Cascades
of Whatcom and Skagit Counties.
Winter Storm Watch from Sunday afternoon through Monday
evening for Cascades of Snohomish and Northern King
Counties-Cascades of Whatcom and Skagit Counties.
Winter Weather Advisory from 5 AM Monday to 5 PM PST Tuesday
for Cascades of Pierce and Lewis Counties-Cascades of
Southern King County.
PZ...Small Craft Advisory until 1 AM PST Sunday for West Entrance
U.S. Waters Strait Of Juan De Fuca.
Small Craft Advisory until 5 AM PST Monday for Central U.S.
Waters Strait Of Juan De Fuca-East Entrance U.S. Waters
Strait Of Juan De Fuca.
Small Craft Advisory until 8 AM PST Sunday for Northern Inland
Waters Including The San Juan Islands.
Small Craft Advisory from 5 AM to 11 PM PST Sunday for
Admiralty Inlet.
Small Craft Advisory until 11 AM PST Sunday for Puget Sound
and Hood Canal.
Small Craft Advisory until 2 PM PST Sunday 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.
&&
$$
NWS SEW Office Area Forecast Discussion