Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
511
FXUS66 KSEW 260435
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
835 PM PST Tue Nov 25 2025
.SYNOPSIS...
A warm front will produce lowland rain and mountain snow becoming
mostly rain late tonight into Wednesday morning. A second system
will bring another round of precipitation Wednesday afternoon into
Thursday with some potential for breezy conditions Thursday afternoon
and evening. The pattern looks to trend drier and eventually
cooler Friday into early next week.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
A warm front is lifting northward across Western Washington tonight.
The 00Z KUIL sounding showed a sliver of warmer air above 3500 feet
and temperatures are creeping upward at Hurricane Ridge. We`re
starting to see a surface reflection of the front now with
southerly winds picking over the Southwest Interior. All of this
amounts to rising snow levels along with the previously advertised
threat of freezing rain in the Cascade passes later tonight. Thus
far, Steven Pass and Snoqualmie have picked up 9 and 4 inches of
snowfall respectively. We`re still on track to see another brief
lull in precip during the daylight hours of Wednesday before another
frontal system spreads additional precip across the area Wednesday
night through much of Thanksgiving. As discussed last night around
this time, this system will be weakening as it arrives. So, overall,
wind won`t be much of a concern with this system. It will, however,
keep easterly flow going in the Cascade passes which has a way of
producing a wintry mess of conditions. Please keep that in mind if
you have travel plans that include them both Wednesday night and/or
Thanksgiving Day. Previous discussion follows with update to the
aviation portion. 27
Precipitation associated with the first of the two systems
expected over the next few days has begun to move inland this
afternoon. Snowlevels at or around 2500 feet this afternoon, as
expected has helped that precipitation fall as snow at all the
passes this afternoon with anywhere from 1 to 3 inches
accumulating as of 2 PM between Stevens and Snoqualmie passes.
This is expected to continue, with a good chance at a period of
mixed precipitation, including freezing rain at both Stevens and
Snoqualmie Passes tonight as conditions warm aloft and cold
easterly flow persists at the passes themselves. Low level
easterly flow at the passes should ease early Wednesday morning
allowing precipitation to fully transition to rain.
Overall the precipitation forecast remains consistent with a
good chance at a break in the day Wednesday, before warm frontal
precipitation pushes back into the area from the southwest
later in the afternoon and evening. This is associated with a
developing system over the eastern Pacific that ensembles have
been showing moving inside of 130W Thursday morning. The
ensembles have trended further south with the track and strength
of the surface low. There is increasing confidence in the low
weakening as it approaches the coast, with still some
variability on the ultimate track, which is now trending
somewhere from the northwest Oregon coast and the central
Washington coast. Overall this system will boost precipitation
again Wednesday night through much of Thursday with snow levels
above 5500 feet and as high as 7000 feet at times. In addition,
as the surface low tracks closer to the coast expect widespread
breezy conditions with gusts to 30 mph a good bet.
Precipitation may linger a bit later into Thursday evening, but
overall storm total amounts remain consistent with earlier
forecasts.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
The overall pattern will trend drier into Wednesday, with
ensembles in solid agreement of a high amplitude ridge
developing over the eastern Pacific and becoming the dominant
feature in the overall pattern through the weekend. There is
some uncertainty regarding the potential for a weak system
affecting western Washington late in the weekend - but given
the pattern this would be a brush-by at best. Overall expect
drier conditions with a trend to cooler Sunday morning into
Monday with 70% chance of some lowland locations - especially
south of Puget Sound along the I-5 corridor dipping down to near
freezing. Otherwise expect near normal high temperatures and
slightly below normal temps for most locations into early next
week.
&&
.AVIATION...
Westerly flow continues aloft as a warm front lifts northward across
Western Washington. This will continue to produce widespread IFR or
occasional LIFR ceilings along with surface visibilities reduced to
2 to 4 statute miles at times. Warm frontal precipitation will
decrease overnight, but poor ceilings and occasional reduced surface
visibility is likely to persist through much of Wednesday morning.
Some brief, albeit marginal, improvement is expected by Wednesday
afternoon for interior terminals, but ceilings are expected to
deteriorate back to low MVFR in increasing precip across the area
Wednesday evening as another frontal system approaches.
KSEA...Precipitation will ease overnight, but ceilings are
likely to fluctuate between IFR or low MVFR through at least 18Z
Wednesday with surface visibility dropping to 3-5SM at times. This
is pretty typical with the passage of a warm front. Confidence in
significant improvement for Wednesday afternoon is not high.
Increasing low level easterly flow may help erode the low ceilings
briefly Wednesday afternoon, but the arrival of the next system will
bring low MVFR ceilings back into the terminal by late evening.
Surface winds E/SE 5 to 8 knots veering more southerly overnight,
then backing to easterly again Wednesday afternoon. 27
&&
.MARINE...
A small craft advisory remains in the effect for the coastal waters
and portions of interior waters as a frontal system moves across the
area. Winds likely peak this evening, reaching back beneath advisory
thresholds by early morning Wednesday. However, may need to extend
the SCA for the coastal zones due to seas (either remaining above 10
ft or due to steepness - both are equally possible given the latest
trends and guidance). A bit of a lull in wind follows later
Wednesday, but another strong front will bring another round of
advisory strength winds Thursday. Late in the week, high pressure
begins to rebuild over the coastal waters into the weekend. Will
need to monitor the strength of any northeast flow developing, but
at this point strong Fraser outflow isn`t particularly likely.
Cullen
&&
.HYDROLOGY...
The first in a series of system has moved widespread
precipitation into the area today, with a second system bringing
another round Wednesday evening through Thursday. Snow levels
especially Wednesday through Thursday evening will remain above
5000 feet. The flood threat for most rivers remains minimal,
with the primary focus remaining the Skokomish. The current
forecast has river levels cresting just below flood stage
Thursday morning, and this may hinge on the second push of
moisture Wednesday into Thursday evening. The flood potential
Outlook for Mason County continues to look on track and will
remain unaltered at this time.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Winter Weather Advisory until 4 AM PST Wednesday for Cascades
of Pierce and Lewis Counties-Cascades of Snohomish and
Northern King Counties-Cascades of Southern King County.
PZ...Small Craft Advisory until 1 AM PST Wednesday 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-
East Entrance U.S. Waters Strait Of Juan De Fuca.
&&
$$
NWS SEW Office Area Forecast Discussion