766
FXUS66 KSEW 130406
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
806 PM PST Wed Nov 12 2025

.SYNOPSIS...
Active conditions continue across the region through the end of
the week and into this weekend with several rounds of rain and
higher elevation mountain snow, though no significant impacts
are forecast. Better chances for drier conditions early next
week, with high confidence in cooler temperatures.

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
Forecast remains on track this evening with increasing shower
coverage across the interior portions of Western Washington as
the next system moves onshore. The remainder of the previous
short term section remains valid and follows.

The heaviest precipitation occuring Thursday morning as low
gets closer to the area. The supporting upper level trough,
however, will dig southward on Thursday, pulling the low center
southwestward towards southern Oregon and northern California.
Rain coverage will decrease Thursday evening but showers will
persist Thursday night and into much of Friday. Through Friday
afternoon, total forecast rainfall amounts will be in the
0.25-0.75" across most of the lowlands, with 1-3" possible in
the mountains and coast. Snow levels currently around 8000 ft
will lower to around 4000-4500 ft Thursday night, which will
allow for some accumulating snow in the passes. Because the
upper trough, and thus, the coolest air aloft being placed
farther south, the resultant snow level forecast has increased.
Therefore, snowfall forecasts have also decreased, with just a
few inches along Rainy/Washington Pass on SR-20 and no
accumulations in a rain/snow mix along Stevens and Snoqualmie
Pass.

Temperatures will be a bit above average, with highs in the
upper 50s to near 60, and lows in the mid 40s up to near 50
Thursday. Highs will be a bit cooler, in the low 50s Friday.


&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Flow aloft turns more zonal on Saturday, which will allow for
additional weak waves to move through Friday night into
Saturday, with a larger trough to move through Sunday into early
next week. The main bulk of the precip will fall late Friday
night into early Saturday and then during the day Sunday. QPF
amounts are almost identical to what is detailed in the short
term section. Snow levels will rise back above 6000 ft Saturday.
Accumulating snow is not expected until Sunday night when snow
levels drop to around 3000-3500 ft. However, showers will really
taper off by then, so any accumulations will likely be very
light (an inch or less) at the passes. Drier conditions Monday
into early next week, with the next more impactful system not
expected until mid to late week next week.

Temperatures will remain in the mid to upper 50s this weekend,
with much cooler temperatures next week. Highs in the upper 40s
to near 50, with lows in the mid 30s to near 40.

62

&&

.AVIATION...
A warm front will lift north across western WA tonight and will
continue to bring light rain to the area. The flow aloft will
remain southwesterly through the period as an upper level trough
continues to dig southward just offshore the West Coast.

Mostly VFR conditions over W WA this evening although along the
coast there is a mix of MVFR to IFR conditions as well as in the San
Juans. As rain increases in coverage tonight into Thursday when the
trailing front shifts inland, more widespread MVFR conditions will
emerge by Thursday morning.

KSEA...VFR this evening with light rain possible at the terminal at
times. Southeasterly winds ranging 4 to 8 kts for the TAF period.
Lower clouds, MVFR conditions, and more widespread rain expected to
move in by early Thursday morning, likely between 10-12Z and remain
in place for the rest of the TAF.

14/18

&&

.MARINE...
Surface high pressure will shift eastward allowing for a low
pressure system to approach the area waters tonight and into
Thursday morning. This will continue to bring small craft
advisory winds and seas above 10 feet along the coastal waters.
The aforementioned low pressure will slowly shift inland,
allowing onshore flow to resume for most area waters on
Thursday. Small craft advisory winds will continue at times in
the coastal waters.

Combined seas this afternoon 8 to 10 feet will slowly build
upwards to 11 to 13 feet by Thursday night. Seas will lower
on Friday but will likely remain generally around 9 to 10 feet
and continue through the weekend.

Mazurkiewicz

&&

.HYDROLOGY...
A series of systems will move across the region today and through
the weekend. While conditions will be wetter, the systems look to
remain rather progressive at this time. Rises will be possible on
area rivers over the weekend, with the most notable rise expected on
the Skokomish River in Mason County. River flooding will be possible
on the Skokomish River by late this weekend. Elsewhere, river flooding
is not expected at this time.

14

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 4 AM PST Friday for 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.

&&

$$