Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
714
FXUS66 KSEW 141230
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
430 AM PST Sun Dec 14 2025
.SYNOPSIS...
River flooding continues across areas of western Washington.
A weak front crosses the region early today. A stronger system
will follow Monday into Tuesday, bringing heavier precipitation
and strong winds for much of the region areas. A deeper trough
will bring cooler air and the potential for heavy mountain snow
Tuesday night into Wednesday. Conditions remain unsettled heading
into late week with additional rain and mountain snow expected.
&&
.SHORT TERM /TODAY THROUGH WEDNESDAY/...
A weak front crossing the area this morning is bringing some
increase in rain and cloud cover across the area. Rain will move
inland by early Sunday, but expect overall amounts to remain
rather light, with most areas only expected to receive a few
hundredths to a tenth of an inch across the interior and a few
tenths along the coast. Snow levels will remain rather high
(generally between 6000-8000 ft), so rainfall amounts in the
mountains are generally expected to range from a quarter of an
inch to an inch in spots, but are not expected to bring
additional impacts at this time.
A different story emerges Sunday night into Monday, when the
next atmospheric river taking aim at the region. Snow levels
will remain rather high at the onset (above 7500 ft), and
rainfall amounts through Monday and into early Tuesday look be
be on the order of around an inch for the lowlands and 2-4
inches in the mountains through late Monday, with the mountain
amounts highest in the Cascades from around King County
northward. This would have the potential to bring prolonged or
renewed flooding on many areas rivers - see the hydrology
section for additional details.
While the strongest winds will likely in the favored locations
along the coast and in the far northwest interior, confidence
continues to increase in the potential for 40-45 mph gusts
across a large swath of the region with this system. Ensemble
guidance suggests a high probability (>80% for 30-40 mph gusts
and still about a 60-70% chance for 45+ mph in the favored
locales) of seeing winds reach close to, if not exceeding
thresholds, and especially given the very saturated conditions
across the region, have proactively issued a wind advisory for
the lowlands to cover tonight through Monday.
Additional moisture on the backside of the atmospheric river
continues into Tuesday, with another front crossing the region
later Tuesday into Wednesday. This could bring additional
rainfall to the lower elevations, but a cooler air mass arrives
with this, with snow levels likely dipping down to around
3000-4000 ft and bringing significant snow to the mountains
Tuesday night into Wednesday.
One additional concern for the short term time period will be
the potential for high surf along the Pacific coastline at times
this week. While seas near the coastline should begin to
increase into the 16 to 19 ft range, the dominant periods look
to be short enough to limit the overall energy and keep things
just shy of criteria. Nevertheless, this will be something else
to closely monitor in the days ahead.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
The pattern stays active and rather damp through much of the
week ahead, but with lower snow levels that will bring a more
typical pattern of mountain snow and lowland rain through the
remainder of the week. Temperatures likely trend cooler during
the late stages of this week with daytime highs largely only
topping out in the mid to upper 40s and overnight lows trending
into the 30s from Thursday onward. Clusters in ensemble members
begin to diverge a bit more toward the later week, but all
maintain a fairly active pattern. 12
&&
.AVIATION...
Weak front moving inland today and dissipating. Warm front
north of the area tonight with another front moving inland
Monday. Southerly flow in the lower levels increasing overnight
into Monday morning.
VFR ceilings this morning with the exception of the coast with
IFR ceilings. Areas of MVFR ceilings over the interior 17z-22z
as the front dissipates over the interior. VFR ceilings this
evening lowering to MVFR overnight. Southerly winds picking up
overnight with 15 to 25 knot winds with higher gusts after 12z
Monday.
KSEA...VFR ceilings. Chance could see MVFR ceilings at times
late morning/early afternoon. Ceilings lowering overnight to
MVFR by 12z Monday. Southerly winds 4 to 8 knots increasing to
10 to 15 knots with gusts to 25 knots around 12z Monday. Felton
&&
.MARINE...
A weak front crossing the waters will bring advisory strength
winds to the coastal waters and building seas today. A stronger
front late Sunday through Monday will bring even stronger winds.
The gale warning for the coastal waters has been expanded to
included the west entrance Strait of Juan de Fuca, as well as
the corridor extending from Puget Sound/Hood Canal north
through the northern Salish Sea. Ensemble forecast guidance
continues to suggest a 60-70% chance of a period of gale force
southerly gusts through these areas. In addition to the winds,
expect seas to build to 18-20 ft early in the week and to remain
elevated through the week ahead as the pattern remains active.
&&
.HYDROLOGY...
Most rivers will continue to recede through tonight. Atmospheric
river arriving Monday morning with rivers rising again by late
morning. Even with the rises most of the rivers staying below
flood stage Monday. Rivers going over flood stage will be the
ones that will have not dropped below much below flood stage
over the weekend like the Skagit, Cedar, White and Cowlitz below
Mayfield Dam.
Rain easing Monday night into Tuesday before the tail end of the
atmospheric river reaches the area later Tuesday into Wednesday
increasing precipitation rates. This second round of precipitation
will drive some rivers above flood stage with major flooding
possible along the Skagit and lower reaches of the Snoqualmie.
Cooler air moving into the area Tuesday night adds some
uncertainty to the river levels. Current forecasts have snow
levels dropping to 2000 to 2500 feet by Wednesday morning. There
is more moisture with this second surge of the atmospheric
river but the cooler air will keep some of the moisture in the
mountains in the form of snow. This combination makes for tricky
river forecasting.
A flood watch is in effect from Monday morning through Thursday
afternoon across the lowlands. Felton
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Wind Advisory from 10 PM this evening to 10 PM PST Monday for
City of Seattle-Downtown Everett / Marysville Area-
Eastern Kitsap County-Eastside-Foothills of the Western
and Southern Olympic Peninsula-Grays Harbor County Coast-
Island County-Lower Chehalis River Valley-Lowlands of
Lewis and Southern Thurston Counties-Lowlands of Pierce
and Southern King Counties-Lowlands of Western Skagit and
Northwestern Snohomish Counties-Lowlands of Western
Whatcom County-Middle Chehalis River Valley-Northern Hood
Canal-Northern Washington Coast-Olympia and Southern
Puget Sound-Port Townsend Area-San Juan County-Shoreline
/ Lynnwood / South Everett Area-Southern Hood Canal-
Western Strait of Juan de Fuca-Willapa and Black Hills.
Flood Watch from Monday morning 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-City
of Seattle-Downtown Everett / Marysville Area-Eastern
Kitsap County-Eastern Strait of Juan de Fuca-Eastside-
Foothills and Valleys of Central King County-Foothills
and Valleys of Pierce and Southern King Counties-
Foothills and Valleys of Snohomish and Northern King
Counties-Foothills and Valleys of Thurston and Lewis
Counties-Foothills and Valleys of the North Cascades-
Foothills of the Western and Southern Olympic Peninsula-
Grays Harbor County Coast-Lake Crescent Area Including US
101-Lower Chehalis River Valley-Lowlands of Lewis and
Southern Thurston Counties-Lowlands of Pierce and
Southern King Counties-Lowlands of Western Skagit and
Northwestern Snohomish Counties-Lowlands of Western
Whatcom County-Middle Chehalis River Valley-Northern Hood
Canal-Northern Washington Coast-Olympia and Southern
Puget Sound-Olympics-Port Townsend Area-Shoreline /
Lynnwood / South Everett Area-Southern Hood Canal-Western
Strait of Juan de Fuca-Willapa and Black Hills.
PZ...Gale Warning from 10 PM this evening to 4 PM PST Monday for
Admiralty Inlet-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-East Entrance U.S. Waters Strait Of
Juan De Fuca-Northern Inland Waters Including The San
Juan Islands-Puget Sound and Hood Canal-West 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 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