Weather alerts for the NWS Seattle WA forecast area

000
FXUS66 KSEW 281010
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
310 AM PDT Wed Oct 28 2026

.SYNOPSIS...
Upper level low near Vancouver Island this morning will not move
much in the next couple of days ending up off the Washington
coast Friday. The low will weaken to a trough Saturday and move
inland Saturday night. Upper level ridge building offshore 
Sunday will move over Western Washington Monday and Tuesday.

&&

.SHORT TERM /TODAY THROUGH FRIDAY/...
Satellite imagery shows cool upper level low centered near 
Vancouver Island early this morning. Wave clouds over and to the
east of the Cascades good indication of some decent winds 
aloft. Camp Muir at 10,000 feet on Mount Rainier reporting 49 
mph with gusts to 66 mph. Showers rotating around the low over 
much of Western Washington at 3 AM/10Z. Temperatures were in 
the 40s.

Upper level low not moving much today. Showers will continue to
spin around the low and move into Western Washington. This
afternoon 500 mb temperatures near -30C, convective temperatures
in the mid 50s, lifted indexes near 0 and lapse rates around 
7.5 C/KM. All this adds up to a chance of thunderstorms late in 
the afternoon. Snow levels in the 3000 to 3500 foot range. 
Heaviest snowfall occurring early this morning. Paradise on 
Mount Rainier reported 2 inches of new snow between midnight and
1 AM ( thanks to our friends at the Northwest Avalanche Center 
for the data ). New snow amounts today will be heaviest around
Mount Rainier, up to 6 inches. Just a couple more inches of new
snow elsewhere in the Cascades. Winter Weather Advisory will
remain up until 5 pm this afternoon. Cool day in the lowlands 
with the clouds and showers. Highs in the lower to mid 50s.

Little change in the pattern tonight into Thursday. Upper level
low drifts slowly south and west ending up west of KUIL by 00z 
Friday. Showers continuing to rotate around the low moving into 
Western Washington. The low does weaken a touch with the winds 
aloft easing. This will weaken the orographics in the mountains 
so even though the shower activity will continue new snow 
amounts will decrease. Light additional accumulations in the 
forecast. Lows tonight in the mid 30s to lower 40s. Highs 
Thursday again in the lower to mid 50s. 

Low drifting south Thursday night and Friday with the flow aloft
becoming southwesterly. This is another negative for much in 
the way of accumulating new snow in the mountains even as snow 
levels remain in the 3000 to 3500 foot range. For the lowlands a
continuation of a chance of showers/showers likely forecast. 
Lows in the mid 30s to lower 40s. Highs in the lower to mid 50s.
Felton

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Models in pretty good agreement with the low weakening and 
continuing to drift south Friday night into Saturday. Flow aloft
becoming southerly and with the jet moving inland to the south 
pops becoming confined to the western half of the area by 
Saturday afternoon. Low weakens to an upper level trough and 
moves inland Saturday night. Upper level ridge building off the 
coast Sunday moving over Western Washington Sunday night and 
Monday. The ridge will weaken a little Tuesday. Still a few 
ensemble solutions with a warm front sneaking over the ridge 
nicking the coast Sunday night and Monday so will have slight 
chance pops for the north coast. With the ridge aloft and the 
low level flow turning light offshore the potential for fog 
exists both Monday and Tuesday morning. Some of the ensemble 
solutions indicating the ridge will be a little dirty with high 
cloud cover getting into the area. With this in mind have only 
gone for patchy or areas of fog both mornings. Highs mostly in 
the mid 50s. Lows in the mid 30s to lower 40s Saturday and 
Sunday cooling to the upper 20s and 30s Monday and Tuesday. 
Felton

&&

.AVIATION...Northwesterly flow this morning shifting more westerly 
to southwesterly by this evening. Surface winds will remain south to 
southwesterly throughout the TAF period, although speeds will start 
from breezy with some occasional gusts to settling down into the 5-
10 kt range this afternoon and evening.

Widespread rainfall this morning resulting in lower cigs with 
widespread MVFR to IFR conditions at most terminals. However, some 
terminals such as HQM, OLM and CLM are reporting VFR conditions as 
of 2 AM PDT. That said, locations under rainfall will likely remain 
under the lower cigs while those that see precip move on do have the 
potential to improve up a category or two. Ultimately, given how 
widespread precip is, would plan for MVFR or lower conditions until 
mid to late morning before conditions begin to improve back to VFR 
by this afternoon. Once VFR conditions are met, will likely remain 
there for the remainder of the TAF period, with an exception 
possibly being OLM due to their fog-prone nature.

KSEA...MVFR conditions in place and with precip still upstream from 
the terminal, would expect MVFR to linger into the late morning 
hours. Should start to see improvement to VFR conditions by 21Z this 
afternoon, even though lingering showers will be a possibility. 
Breezy winds mainly in the 8-12 kt range with occasional gusts up to 
20 kt in place for much of the morning, but as per above discussion, 
should see speeds ease this afternoon to 5-10 kts. Direction is 
expected to remain south to southwesterly throughout the TAF period.

18

&&

.MARINE...Northwesterly winds along the outer coastal waters 
will linger into early this morning, but will ease after 5 AM PDT 
this morning. Same for seas. As such, timing on inherited headlines 
looks good and will run its course unaltered.

Following suit, winds will also ease across the inland waters as the 
accompanying surface low drops into the area and tracks southward 
along the coastal waters. As it does so, this will allow for flow to 
turn back offshore, with offshore flow persisting the second part of 
the week. 

Seas easing throughout the day, ranging 7 to 10 ft early this 
morning favoring 6 to 9 ft by noon today. 5 to 7 ft waves are 
expected by tonight and remain there into Thursday. Further 
subsiding of seas is expected, with 4 to 6 ft expected by the 
weekend.

18

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Winter Weather Advisory until 5 PM PDT this afternoon for 
     Cascades of Pierce and Lewis Counties-Cascades of 
     Snohomish and Northern King Counties-Cascades of Southern 
     King County-Cascades of Whatcom and Skagit Counties.

PZ...Small Craft Advisory until 5 AM PDT early this morning 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.

&&

$$