Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
775
FXUS66 KSEW 171702
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
902 AM PST Mon Nov 17 2025
.SYNOPSIS...
Showers will continue across the region through Tuesday as a
series of disturbances cross the area. Drier weather is
expected late Tuesday into Wednesday as a ridge briefly builds,
giving a small chance for the first peaks of sunshine in a
short while. Rain chances will increase again late in the week
with a more significant round of precipitation possible late
next weekend.
&&
.SHORT TERM /TODAY THROUGH WEDNESDAY/...Showers continue to move
across the region this morning with a more robust disturbance
located to the south of the area. While the bulk of the system
continues to remain positioned well to our south, will see an
embedded impulse provide a focus for heavier precipitation later
today into tonight, most likely for the northern tier of the
area. This shouldn`t provide for much in the way of impacts, but
some snow down into the higher Cascade elevations can be
expected as snow levels begin to dip from around 6,000 feet to
around 3,500 ft Tuesday as moisture wanes. This could bring a
few inches down around Rainy Pass in the North Cascades, and
it`s worth noting that ensemble guidance continues to depict a
rather large spread in potential amounts. Will need to closely
monitor satellite trends and assess how high- res ensemble
guidance is capturing this evolution.
Otherwise, with the splitting system and favorable support
departing the region, expect to see a brief period of drier
conditions across the region as high pressure builds aloft. This
will bring some slightly cooler temperatures as the air mass
cools, but also the potential for a little sunshine between the
clouds for many Tuesday afternoon. Dry conditions likely
continue into Wednesday with the ridge remaining in place.
Depending on how the cloud cover evolves, will need to also
monitor the fog potential each of the next few mornings.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Expect the high pressure ridge to break down later in the week,
again opening the door for a return of a more active pattern.
Another system likely arrives around Thursday with additional
(possibly heavier) precipitation later in the weekend, though
ensemble guidance continues to show a wide spread in potential
outcomes with this next one. At the high end, there is some
potential for heavier snow in the high Cascades and possibly
bringing snow accumulations down to Snoqualmie and Stevens
passes, though it`s worth noting that some outcomes are
significantly less impactful. At the least, a return to more
widespread cloud cover and periods of precipitation is most
likely for the second half of the week. Cullen
&&
.AVIATION...A stalled frontal boundary over the interior of
Western Washington this morning will eventually move east of the
Cascades this afternoon with southwest flow aloft transitioning to
west-northwesterly as a weak upper trough moves onshore. Widespread
IFR or low MVFR ceilings around Puget Sound will be slow to improve
this afternoon with higher ceilings expected near the coast. Light
surface flow and plentiful low level moisture will contribute to the
development of widespread IFR or low MVFR stratus tonight into
Tuesday morning.
KSEA...Stalled front in the vicinity of the terminal this morning
will likely keep ceilings on the low end into the early afternoon
hours. Limited improvement is expected this afternoon with ceilings
likely remaining MVFR. Ceilings are expected to deteriorate once
again tonight with low end MVFR or occasional IFR expected for
Tuesday morning. Surface winds light northeasterly this morning are
expected to become light and variable this afternoon before
switching to southerly 4 to 7 knots overnight. 27
&&
.MARINE...A modest increase in onshore flow overnight behind an
exiting frontal system will weaken today as broad surface ridging
rebuilds over the coastal and offshore waters. The ridge will shift
east of the Cascades on Wednesday as a splitting front approaches
the outer coastal waters. This will turn the flow east to
southeasterly midweek. Broad surface ridging rebuilds late in the
week before another weak front approaches the waters by the weekend.
Coastal seas will dip below 10 feet on Tuesday and Wednesday before
another larger swell train arrives Thursday into the weekend. 27
&&
.HYDROLOGY...
No flooding is expected through the week ahead. A stronger
weather system next weekend could bring periods of heavier rain
and will be the next time to watch with respect to hydrologic
concerns.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 4 PM PST this afternoon 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.
Small Craft Advisory until 10 AM PST this morning for Central
U.S. Waters Strait Of Juan De Fuca.
Small Craft Advisory until 10 PM PST this evening 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