Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
696
FXUS66 KSEW 280401
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
901 PM PDT Sun Sep 27 2026
.SYNOPSIS...
Dry tonight and Monday as surface high pressure weakens. Next
system moving down the British Columbia coast arrives on
Tuesday. Weak upper level ridge building Wednesday. Possible
system moving by to the north later Thursday into Friday. Strong
upper level ridge building Saturday with the low level flow
trying to turn offshore.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
No updates to the forecast this evening. Latest satellite shows
mostly clear skies across the CWA with split-flow aloft and
surface high pressure. Cloud coverage will remain limited
tonight as efficient radiation cooling ensues across the area.
Patchy fog, primarily across river valleys is favored to develop
with widespread overnight lows in the 40s. Can`t rule out few
areas flirting with the upper 30s.
Dry weather is favored to remain on Monday as surface high
pressure weakens. High temperatures won`t stray too far from
average, typical for late September with highs in the 60s.
On Monday night a frontal system will enter as rain develops
along the coast and northern interior. Winds will become breezy
with southerly gusts up to 25 to 35 mph with gusts near 40 mph
across western Whatcom.
The aforementioned frontal system will progress through the
remainder of the area on Tuesday as rain spreads over the
region during the morning. Windy conditions continuing over the
Northwest Interior. There is a chance wind advisories made be
needed. Highs in the lower 60s. Rainfall will gradually diminish
into the evening hours as conditions trend drier overnight.
McMillian
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Latest ensembles show a warming and drying trend through the
end of the week into the weekend. An upper level ridge will
build over the area for high temperatures in the mid 60s likely
throughout the end of the week. Potentially, could even see even
a 70 degree day over the weekend. Stay tuned!
Mazurkiewicz
&&
.AVIATION...
A weak upper trough will shift east tonight with the
flow aloft over western WA becoming more zonal. Skies are VFR
with the trend continuing overnight for the interior. At the
coast, expect shallow marine layer clouds pushing inland for
MVFR conditions. Patchy low clouds or fog may form around the
south sound early Monday. Increasing clouds Monday afternoon
with rain reaching the coast after 00z Tue. 33
KSEA...VFR conditions through the period. N wind around 10 kt
easing to 5 kt after 03z. 33
&&
.MARINE...
The next frontal system arrives late Monday into
Tuesday with increasing southerly winds over all waters - Small
Craft Advisories are in effect. Winds will turn more westerly
through the strait Tuesday afternoon. Meanwhile, expect elevated
seas with swells reaching 10-11 ft. Onshore flow will ease late
Tuesday night. The flow will then turn offshore on Wednesday
with a thermal trough along the coast. Light offshore flow
continues through the end of the week. 33
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory from 5 PM Monday to 5 PM PDT Tuesday 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-Puget Sound and Hood Canal-West
Entrance U.S. Waters Strait Of Juan De Fuca.
Small Craft Advisory from 5 PM Monday to 5 AM PDT Wednesday
for Central U.S. Waters Strait Of Juan De Fuca-East
Entrance U.S. Waters Strait Of Juan De Fuca.
Small Craft Advisory from 11 PM Monday to 5 PM PDT Tuesday for
Northern Inland Waters Including The San Juan Islands.
&&
$$
NWS SEW Office Area Forecast Discussion