Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
674
FXUS66 KSEW 310522
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
1022 PM PDT Mon Mar 30 2026
.SYNOPSIS...
Expect cold and cloudy conditions into Tuesday under westerly
flow aloft. A frontal system will cross the region on
Wednesday, bringing breezy winds alongside lowland rain and
mountain snow. Showers will linger over the mountains Thursday
before drier and warmer conditions settle into western
Washington over the weekend.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
No major updates have been made to the forecast this evening as
things remain on track. The rest of the previous discussion can
be found below as well as an update to the aviation sections.
Zonal flow will develop by tonight as upper level flow turns
more westerly, bringing in high clouds that will likely limit
the extent of fog and low stratus early Tuesday morning.
However, patchy fog is still possible, especially where cloud
cover is thin, and confidence is low over the extent of fog in
the morning. Upper level flow will turn southwesterly by Tuesday
afternoon, with warmer air aloft allowing for high temperatures
to warm a degree or two. Cloud cover will increase throughout
the day as a trough approaches the coast.
A frontal system will cross western Washington on Wednesday,
bringing in widespread lowland rain, mountain snow, and breezy
winds. Winds will increase along the Pacific Coast and through
the Strait of Juan de Fuca to Whidbey Island Wednesday morning,
with max wind gusts in the ballpark of 35 to 45 mph. The
lowlands will see steady rain, measuring up to a half inch,
throughout the day Wednesday, with lingering snow showers
continuing over higher terrain Wednesday night. With snow levels
around 3000-3500 feet, the mountains will see snow
accumulations of around 3 to 6 inches.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
The low pressure system will shift inland over Oregon on
Thursday, with potential for wrap around moisture to continue
light snow showers over the Cascades. Elsewhere, conditions are
favored to dry out with some sun breaks in the afternoon.
An upper level ridge is then favored to build over the western
US over the weekend, bringing warmer and drier conditions to
western Washington. While a weather system may try to overrun
the ridge, any precipitation is expected to remain north of the
Canadian border. Mild conditions will prevail, with highs near
60 degrees across much of the lowlands on Saturday and Sunday.
15
&&
.AVIATION...
High pressure aloft remains in place into Tuesday. Expect VFR
conditions area-wide this evening with variable high clouds
streaming overhead. Breezy northerly surface winds through the
Puget Sound terminals ease later tonight. Increasing high clouds
and drier surface conditions should preclude widespread fog
development tonight, but still around at 20% chance for the more
sheltered, fog prone terminals including KOLM and KPWT. Shallow
low clouds clear Tuesday morning with VFR conditions into the
afternoon.
KSEA...VFR conditions with passing high clouds. North surface
winds decrease overnight. Less than 5 percent chance for any low
clouds or fog through the morning, with VFR conditions through
Tuesday with increasing high clouds.
&&
.MARINE...
Surface high pressure over the coastal waters this afternoon for
northerly winds. Light winds will continue over the area waters
through Tuesday. A low pressure system will start to approach
the waters Wednesday morning with increasing southerlies over
much of the waters, with headlines likely needed in the next
day for winds trending near small craft advisory strength. Winds
will peak mid Wednesday afternoon for most of the waters,
decreasing into Thursday.
Broad high pressure will redevelop on Thursday and into the end
of the week, bringing generally benign marine conditions to the
waters.
Coastal seas remaining 3 to 5 feet throughout Tuesday. Seas will
then build up to 9 to 11 feet Wednesday morning. Seas will
remain elevated into Thursday before decreasing on Friday and
into the weekend, back down to 3 to 5 feet.
Mazurkiewicz
&&
.HYDROLOGY...
No river flooding is expected over the next 7 days.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...None.
&&
$$
NWS SEW Office Area Forecast Discussion