Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
407
FXUS66 KSEW 051203
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
403 AM PST Thu Mar 5 2026
.SYNOPSIS...
Lingering showers mainly over the mountains today, with more
widespread precipitation returning to the area tonight into
Friday. A cooler system remains on track for late in the
weekend into early next week, bringing needed mountain snow and
some potential for an early morning rain/snow mix for parts of
the interior lowlands.
&&
.SHORT TERM /TODAY THROUGH SATURDAY/...
Post-frontal showers will linger over the Cascades today.
Precipitation associated with warm front will spread into the
area again this evening and loiter through much of the day
Friday. The warmer air mass will boost snow levels to over
5,000 ft by late Friday morning and 6000 to 7000 ft by Saturday
morning. Precipitation should generally taper off Saturday
morning, lingering over the higher terrain. Temperatures will
run in the ballpark of normal with highs in the low 50s and lows
in the upper 30s to low 40s.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
An upper level trough moving across south central Alaska
Saturday evening will help nudge a frontal system south along
the British Columbia coast into western Washington Sunday
morning. This will bring widespread precipitation through the
day Sunday into Monday morning - as well as much cooler air
mass. Snow levels are expected to drop to pass levels by early
Sunday evening and to 1000 to 1300 feet by early Monday morning.
Low level flow is expected to remain onshore, but there remains
a chance for a window with a rain/snow mix for some lowland
locations early Monday morning before temperatures moderate for
rain. The cooler air mass looks to remain in place through the
early part of next week, with the NBM showing 70-80% odds at low
temperatures Tuesday morning at or below 32F for many locations
outside of the urban areas. Periods of lighter precipitation
remain possible, especially over the higher terrain Monday and
Tuesday. Longer range ensemble guidance hinting at the next,
more organized system mid week which will most likely result in
another round of needed mountain snow.
&&
.AVIATION...
Westerly flow aloft continues behind a frontal passage with
deteriorated flight conditions mostly MVFR/IFR as rain/snow showers
continue over the Cascades. Isolated shower activity will continue
over higher terrain this morning with mountain obscuration. Outside
of precipitation, low clouds will continue filling in across the
western Washington terminals with some brief improvement to VFR by
later this afternoon/evening. Conditions will lower again later
tonight to widespread MVFR to IFR in cigs and vis as another frontal
system brings in widespread lowland rain and mountain snow. Surface
winds generally south to west 8 kt or less this morning increasing
to 5 to 12 kt this afternoon with gusts to 20 kt. Higher westerlies
possible through the Strait of Juan de Fuca and over the Cascades.
KSEA...Low end MVFR early this morning with low stratus over the
terminal, likely remaining MVFR through sunrise. Conditions are
favored to slowly improve to low end VFR into the afternoon, then
deteriorate once again to MVFR later tonight as winds ease and
steadier rainfall moves inland. Winds generally southerly 5 to 10 kt
overnight. South to southwest winds increasing this afternoon with
gusts to 25 kt possible.
15
&&
.MARINE...
Winds over the coastal waters have eased this morning - seas
will remain elevated through the morning - dropping to 7 to 8
feet through the afternoon. Onshore flow will linger through the
period with small craft advisory westerlies through the strait
easing during the afternoon. The flow will remain onshore
Friday and Saturday, with the increasing winds and seas
Sunday/Monday.
&&
.HYDROLOGY...
No river flooding is expected over the next seven
days.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Winter Weather Advisory until 10 AM PST this morning for
Cascades of Pierce and Lewis Counties-Cascades of
Snohomish and Northern King Counties-Cascades of Southern
King County.
PZ...Small Craft Advisory until 6 PM PST this evening for Grays
Harbor Bar.
Small Craft Advisory until 10 AM PST this morning for Central
U.S. Waters Strait Of Juan De Fuca-East Entrance U.S.
Waters Strait Of Juan De Fuca-West Entrance U.S. Waters
Strait Of Juan De Fuca.
Small Craft Advisory until 1 PM PST this afternoon 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