Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
038
FXUS66 KSEW 042333
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
333 PM PST Sun Jan 4 2026
.SYNOPSIS...
Unsettled conditions will persist across western Washington
through Monday as troughing continues over the region. A series
of strong frontal systems will bring heavy mountain snow, breezy
winds, and widespread lowland rain Tuesday through Thursday
before an upper ridge builds over the western US.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
A shortwave offshore will continue to spread light shower
activity across the interior this evening. Upper level troughing
will shift inland tonight into Monday, maintaining scattered
showers overnight and into the morning. A cooler air mass will
move into the region, dropping temperatures into the 30s
overnight and allowing snow levels to lower to 2500 to 3000
feet. Shower activity will taper off Monday afternoon,
providing a brief lull before the next incoming system. Major
coastal flooding has ceased this afternoon along the Pacific
Coast and northern Salish Sea coastlines, with minor to moderate
coastal flooding elsewhere. Astronomical tides will continue to
lessen from this point, with minor to moderate coastal flooding
set to continue over the next few days.
A strong frontal system will cross the region on Tuesday,
bringing the next round of significant weather. While winds will
become quite breezy as the cold front digs into western
Washington, some uncertainty remains over how windy conditions
will be. The main story will be snowfall, and with snow levels
lowering well below pass level to near 1500-2000 feet, the
mountains are on track to see significant snowfall with this
system. Forecast models continue to show 24-hour snowfall totals
on the order of 1 to 2 feet Tuesday morning through early
Wednesday morning, with heavy accumulations through the central
Cascade passes. For the lowlands, Tuesday will be a damp and
windy day with rainfall totals ranging generally from a half
inch to an inch.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Precipitation will briefly taper on Wednesday as the frontal
system shifts east of the Cascade crest. Another strong weather
system will be right on its heels, bringing another round of
heavy precipitation to the region Wednesday through Thursday.
This system will likely bring an additional couple of feet to
higher elevations of the Olympics and Cascades, bringing storm
totals to 3 to 4 feet of snow. A Winter Storm Watch has been
issued from Tuesday morning to late Thursday evening as
confidence grows over the potential for significant mountain
snow. The lowlands will see another round of rain reaching a
half inch to an inch during this period.
Forecast confidence decreases towards next weekend as an upper
level ridge builds over the western US. Conditions may dry out
next weekend, but models continue to show potential for another
wet system overrunning the ridge and bringing more precipitation
to the region. While a chance of lowland rain and mountain snow
remains in the long range forecast, temperatures next weekend
will warm up and may reach the low 50s for some areas.
15
&&
.AVIATION...
southwesterly flow aloft turning more westerly as an upper level
trough moves through western Washington. Scattered rain showers
will continue throughout the remainder of the evening, with most
areas currently at VFR/MVFR. This trend will likely continue
into Monday morning, with a mix of VFR and MVFR ceilings
throughout the area. Breezy southerlies this afternoon will
subside, generally staying between 5 to 10 knots this evening.
KSEA...VFR ceilings this afternoon will likely lower overnight
to MVFR at times as scattered showers continue over the
terminal. Southerly winds around 5 to 10 knots will remain
throughout the evening and into the overnight hours.
Mazurkiewicz
&&
.MARINE...
Weak high pressure will start to build over the waters tonight
into Monday, leading to decreasing seas and winds over the area
waters. A stronger weather system will cross over the area on
Tuesday, leading to increased south/southwesterlies over the
coastal waters, along with increased southerlies over the
interior waters, likely small craft advisory strength. These
winds look to continue through Wednesday.
Surface high pressure looks to build over the area Thursday into
Friday which would help marine conditions calm down a bit.
Coastal seas 6 to 8 feet this afternoon decreasing into Monday.
Seas will build again on Tuesday, building upwards to the 14 to
18 foot range, with the highest seas being in the outer coastal
water zones. These elevated seas will continue through
Thursday.
Mazurkiewicz
&&
.HYDROLOGY...
The Skokomish River is expected to crest this evening just below
flood stage and continue to fall into Tuesday morning. It is
expected to crest above minor flood stage later Tuesday with
additional precipitation entering the region. For the remainder
of area rivers no flooding is expected over the next 7 days.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Coastal Flood Advisory from 6 AM to 10 AM PST Monday for
Island County-Lowlands of Western Skagit and Northwestern
Snohomish Counties-Lowlands of Western Whatcom County-San
Juan County.
Winter Storm Watch from late Monday night through Thursday
afternoon for Cascades of Pierce and Lewis Counties-
Cascades of Snohomish and Northern King Counties-Cascades
of Southern King County-Cascades of Whatcom and Skagit
Counties.
Coastal Flood Advisory from 5 AM to 9 AM PST Monday for City
of Seattle-Downtown Everett / Marysville Area-Eastern
Kitsap County-Lowlands of Pierce and Southern King
Counties-Shoreline / Lynnwood / South Everett Area.
Coastal Flood Advisory from 11 AM to 3 PM PST Monday for
Eastern Strait of Juan de Fuca-Grays Harbor County Coast-
Northern Washington Coast-Western Strait of Juan de Fuca.
PZ...Small Craft Advisory until 6 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.
&&
$$
NWS SEW Office Area Forecast Discussion