Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
908
FXUS66 KSEW 012105
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
205 PM PDT Wed Apr 1 2026
.SYNOPSIS...
Widespread precipitation behind a frontal passage will taper off
tonight, with snow showers continuing over the Cascades on
Thursday. Drier and warmer conditions will settle into the
region over the weekend as high pressure builds overhead, with
potential for mostly dry conditions to continue into next week.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
Widespread lowland rain and mountain snow continues this
afternoon as a frontal system continues to cross the region.
Winds have peaked for the day for most areas, except through the
Strait of Juan de Fuca, where elevated post-frontal westerlies
will continue overnight. The bulk of the rainfall over the
lowlands will shift inland later this afternoon, with showers
continuing to stream inland this evening behind the frontal
passage. While a lightning strike or two cannot be ruled out in
these showers, the likelihood is low. Today will be the coolest
day over the next week, with highs peaking several degrees below
normal, in the upper 40s to near 50 across the lowlands.
Precipitation will shift mostly eastward of the Puget Sound
overnight into Thursday as the parent low pressure center moves
onshore over Oregon. A cold front will cross the region Thursday
morning, ending most precipitation with lingering light snow
showers over the mountains and a Puget Sound Convergence Zone
continuing through the afternoon. Temperatures will increase a
few degrees on Thursday with some sun breaks by the afternoon.
As high pressure begins to build northward into western
Washington on Friday, a weather system will skirt the periphery
of the ridge, bringing light rain showers along the northern
Olympic Peninsula, Islands, and Northern Interior. Elsewhere,
conditions will begin to dry out under cloudy skies with some
sun breaks. Temperatures will warm another few degrees into
Friday, with highs in the mid to upper 50s across the lowlands.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
High pressure will amplify over the region over the weekend,
bringing the warmest temperatures of the year so far to western
Washington. Highs will reach the low to mid 60s by Saturday, and
continue to warm into Sunday where some areas along the Cascade
Foothills and south of the Sound could reach 70 degrees. This
also introduces Minor (Yellow) HeatRisk for areas south and
east of the Puget Sound over the weekend.
Forecast confidence decreases into Monday, with models shifting
the upper level ridge eastward. While ensembles maintain chances
for showers early next week, operational forecast models are
trending drier with split flow developing aloft. Monday could
be the warmest day of the period with many areas seeing highs
near 70 degrees, but will have to see how models trend over the
next few days.
15
&&
.AVIATION...
South to southwest flow aloft across Western Washington this
afternoon ahead of a frontal system will turn easterly overnight
then northerly on Thursday as a trailing upper trough axis shifts
eastward. A mix of low end VFR and MVFR in rain ahead of the front
will become primarily MVFR tonight as a somewhat unstable post-
frontal air mass moves onshore.
KSEA...Ceilings are expected to lower to MVFR in rain this
afternoon. Rain will transition to post-frontal showers after
00Z with MVFR ceilings continuing. Surface winds east to
southeasterly 8 to 12 knots into the afternoon will veer south to
southwesterly after 00Z rising to 10 to 15 knots with occasional
gusts of 20 to 25 knots before gradually easing late tonight.
27
&&
.MARINE...
A weakening surface low around 995 millibars will come
ashore near Cape Flattery late this afternoon as an associated
frontal system sweeps onshore across Western Washington. Post-
frontal onshore flow will follow overnight then weaken on Thursday
as weak surface ridging builds across the waters. A surface ridge
will largely remain in place into the coming weekend. Thermally
induced low pressure expanding northward along the Oregon coast will
lead to northerly or weak offshore flow later Saturday into Sunday.
A weak system passing north of the waters will lead to a switch to
onshore flow on Monday.
An additional swell train will arrive on Thursday keeping seas near
the 10 feet before decreasing Friday into the weekend.
27
&&
.HYDROLOGY...
No river flooding is expected over the next 7 days.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Winter Weather Advisory until 11 AM PDT Thursday 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.
PZ...Small Craft Advisory until 4 PM PDT this afternoon for West
Entrance U.S. Waters Strait Of Juan De Fuca.
Small Craft Advisory from 5 PM this afternoon to 11 AM PDT
Thursday for Central U.S. Waters Strait Of Juan De Fuca-
East Entrance U.S. Waters Strait Of Juan De Fuca.
Gale Warning until 5 PM PDT this afternoon for East Entrance
U.S. Waters Strait Of Juan De Fuca.
Small Craft Advisory until 5 PM PDT this afternoon for
Admiralty Inlet-Northern Inland Waters Including The San
Juan Islands.
Small Craft Advisory until 11 PM PDT this evening for Puget
Sound and Hood Canal.
Small Craft Advisory until 11 PM PDT this evening for Coastal
Waters From Cape Flattery To James Island Out 10 Nm-
Coastal Waters From James Island To Point Grenville Out
10 Nm-Coastal Waters From Point Grenville To Cape
Shoalwater Out 10 Nm.
Small Craft Advisory until 5 PM PDT Thursday 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-Coastal Waters From Point Grenville To Cape
Shoalwater 10 To 60 Nm.
&&
$$
NWS SEW Office Area Forecast Discussion