Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
048
FXUS66 KSEW 041028
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
328 AM PDT Sat Apr 4 2026
.SYNOPSIS...
Upper level ridge building over the area today will remain in
place through the weekend. The ridge will drift east Monday.
Upper level trough moving by to the north Monday night and
Tuesday will induce a marine push. Dry northwesterly flow aloft
Wednesday through Friday with an upper level low well southwest
of Western Washington.
&&
.SHORT TERM /TODAY THROUGH MONDAY/...
Satellite imagery shows cloud cover along the north coast and
over the Northwest Interior. Fog has formed in the last couple
of hours in the Southwest Interior and Lower Chehalis Valley.
Temperatures at 3 am/10z were in the mid 30s to mid 40s.
Dry weather in the short term with an upper level ridge building
over the area today and tonight. Patchy fog this morning will
dissipate quickly after sunrise. Frost advisory for the
Southwest Interior and Lower Chehalis Valley will expire at 9
am. The ridge will remain in place Sunday then slowly drift east
Monday. Upper level flow becoming southwesterly later tonight
into Monday. High clouds embedded in the flow aloft moving
through Sunday and Monday. Low level flow turning offshore
today. Offshore flow continuing through Sunday night with the
low level flow becoming light Monday. Warming trend through
Monday. Highs today in the mid 50s to lower 60s, Sunday and
Monday 60s to lower 70s. Lows in the 40s. Felton
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
Classic marine push scenario Monday night into Tuesday. Upper
level shortwave riding by to the north inducing an increase in
low level onshore flow. Much cooler Tuesday with highs in the
lower to mid 50s. Next upper level trough will go by well to the
north and east Wednesday. Dry northwesterly flow aloft
Wednesday through Friday with an upper low off the Northern
California coast remaining stationary. Highs recovering into the
mid 50s to lower 60s Wednesday through Friday. Lows in the 30s
through Thursday morning, mid 30s to lower 40s Friday morning.
Could see another round of frost advisories for the Southwest
Interior and Lower Chehalis Valley Wednesday and Thursday
morning.
&&
.AVIATION...
Westerly flow aloft will continue today as upper ridging centered
south of the region builds northward. There is low confidence for
lows clouds forming in the morning in some spots such as OLM, HQM,
and BLI (would most likely be MVFR if they do form) but
otherwise conditions will remain VFR through the TAF period.
Winds will shift to the north, increasing to 6-12 kts this
afternoon.
KSEA...VFR is expected through the TAF period. Probability for MVFR
clouds this morning remain low at the terminal, though may form as
far south as Tacoma. Northerly winds will increase to 8 to 12 knots
this afternoon after around 21Z, continuing at this speed into
tonight.
21
&&
.MARINE...
High pressure will remain over the waters this weekend while a
thermally induced trough expands northward along the Oregon coast.
This will shift the flow northerly or weakly offshore. Onshore flow
resumes early next week as a frontal system passes to the north. A
strong westerly push is possible along the central and eastern
Strait of Juan de Fuca Monday night into Tuesday.
Seas across the coastal waters will build towards 7-10 ft
Tuesday into Wednesday.
21
&&
.HYDROLOGY...
No river flooding the next 7 days.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Frost Advisory until 9 AM PDT this morning for Foothills and
Valleys of Thurston and Lewis Counties-Lower Chehalis
River Valley-Lowlands of Lewis and Southern Thurston
Counties-Middle Chehalis River Valley-Olympia and
Southern Puget Sound-Willapa and Black Hills.
PZ...None.
&&
$$
NWS SEW Office Area Forecast Discussion