Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
504
FXUS66 KSEW 170921
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
121 AM PST Tue Feb 17 2026
.SYNOPSIS...
A trough will keep the pattern unsettled through much
of the week. Cool temperatures will allow for rain and snow showers
to continue in the lowlands through much of the week, especially
overnight and early morning hours. Mountain snow will also be
possible, but remain light through the week. Potential increases for
a more significant system to produce more substantial precipitation,
breezy winds, and also warmer temperatures.
&&
.SHORT TERM /TODAY THROUGH THURSDAY/...
A mid/upper level low has dug its way southward from Alaska
yesterday, and has parked itself off the coast of Washington. It
will likely remain out there and rotate slowly inland towards the
end of the week, keeping the pattern unsettled with the trough
pattern.
The radar has been active this morning. The main activity has been
along the Pacific Coast, with a heavier area of showers (snow and
possible graupel) pushed through Westport and Ocean City, and
continues to track northward in far west Grays Harbor County.
Additional showers are moving their way across the remainder of
Grays Harbor County up into far west Thurston/West Mason Counties
this morning, and will continue to track northward across the
Olympics. The ensembles continue the current shower activity through
the morning, with a couple HREF ensemble members showing potential
for a band of showers (potentially containing snow) moving up the I-
5 corridor through Olympia this morning. With the temperatures
overnight dropping into the low 30s/upper 20s in this area, the
potential exists for slick surfaces across the portion of I-5 (as
with other roads that remain wet overnight with cool temperatures).
Use caution if driving and/or walking outdoors for possible slick
surfaces. The winter weather advisory as of now will continue
through noon for the US-101 corridor from Crescent Lake through the
Lower Chehalis Valley (including Hood Canal-Willapa and the Black
Hills).
With the trough again in place, this will keep a slight
chance/chance of showers/snow showers in place through midweek.
The current wave of showers will rotate around the low, with
additional development to the south expected to wrap around across
the rest of the interior/Cascades later this morning into the
afternoon/evening. A couple HREF/NAM members enhance some of the
precipitation this evening/overnight across the north Olympics, and
some of the Cascade Foothills in Snohomish/King Counties, but given
the showery nature of this activity, this will continue to be hit or
miss in terms of coverage.
Precipitation chances increase again regionwide going into Wednesday
as the low begins to pivot inland (still wrapping a couple of
troughs on the west side of the low). There will be some Fraser
River outflow overnight Wednesday/Thursday morning, which looks to
cool temperatures a few degrees more (this would concern the north
interior especially Whatcom County with lows in the mid 20s). Highs
are still expected to reach the low to mid 40s during the next few
days. Mountain snow impacts remain relatively minimal through
midweek with light snow rates.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
The aforementioned trough will begin to fill/move in late Thursday,
which will drop the precipitation chances going into the evening. A
couple of the models throw in a ridge on Friday, but a majority of
the ensemble members throw in another trough late Friday into next
weekend. While the ridge may not be enough to keep the region dry
for a day, temperatures will begin to rise a few degrees, reaching
the low 50s again towards the end of the weekend. The main concern
is going to be potential for heavier precipitation, with the
increase of southerly flow bringing in additional moisture into the
region. This includes the potential for heavy mountain snow
(especially in the Olympics). While the threat of flooding remains
low at this time, this may change depending on how the moisture/snow
levels track with this system.
Additionally, the low pressure offshore is expected to generate
higher seas, which may translate to larger waves across the Pacific
Coast Saturday into Sunday, potentially impacting some of the
beaches.
HPR
&&
.AVIATION...
An upper level trough remains in place offshore, with
south/southwest flow aloft decreasing and becoming more west on
Wednesday. Ceilings this morning are split between VFR in the main
interior terminals, and MVFR west of Puget Sound due to showers
passing north across the Olympics this morning.
Additional showers will move up across the I-5 corridor this
morning, spreading across the interior terminals. The cool air
aloft/surface will likely mix in some snow with this shower activity
(especially with the activity moving up through Hood
Canal/Olympics/Pacific Coast this morning). The showers will likely
result in visibility/ceiling reductions down to IFR/LIFR briefly as
they pass over the terminals. The showers and MVFR/VFR ceilings will
continue through the TAF period (with pockets of IFR at times).
Winds remain south/southeast at around 4-6 kt today, decreasing to 5
kt or less tonight/Wednesday.
KSEA...MVFR to VFR ceilings largely expected through the TAF period.
Radar is tracking rain/snow showers moving towards the terminal
around 14-16Z this morning (this may drop conditions further to IFR
briefly as they pass over the terminal).
Probability of any snow sticking remains very low. Some additional
showers may hang around the terminal into the afternoon/evening, but
with minimal impacts. Winds remain S/SE 4-6 kt, becoming 5 kt or
less tonight/Wednesday.
HPR
&&
.MARINE...
A trough will remain offshore through at least Thursday before
moving inland. Showers will be possible at times over the waters
(some of which may be heavy enough to reduce visibilities briefly).
Winds are expected to remain light as the low tracks inland,
switching from southerly to northerly. In the short term however,
the main concern is seas, with a small craft advisory continuing for
the coastal waters, Grays Harbor Bar (and now the west Strait of
Juan de Fuca) through Wednesday morning for 10-13 ft seas. The seas
will drop to 6-8 ft Wednesday as the low begins to propagate inland.
A stronger system may impact the region next weekend, with the
potential for a few gale gusts in the outer coastal waters, small
craft winds in a majority of the waters, and seas increasing up to
16-18 ft on Sunday. Continue to monitor the forecast for updates on
this potential impactful system.
HPR
&&
.HYDROLOGY...
No river flooding is expected over the next 7 days.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Winter Weather Advisory until noon PST today for Foothills of
the Western and Southern Olympic Peninsula-Lake Crescent
Area Including US 101-Lower Chehalis River Valley-
Southern Hood Canal-Willapa and Black Hills.
PZ...Small Craft Advisory until 10 PM PST 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-Grays Harbor Bar-West Entrance U.S.
Waters Strait Of Juan De Fuca.
Small Craft Advisory until 4 AM PST Wednesday 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