292
FXUS66 KSEW 132116
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
216 PM PDT Mon Oct 13 2025
.SYNOPSIS...Weak high pressure building into the region, combined
with offshore flow, and will bring cool and dry conditions to the
western Washington on Tuesday and Wednesday. A weak system will
bring the return of showers to the area Thursday into Friday with
a stronger, wetter system expected to move into the area this
weekend.
&&
.SHORT TERM /TODAY THROUGH WEDNESDAY/...The upper low that brought
showers and mountain snow on Sunday has now shifted to our south,
with dry northerly flow currently over western WA. Gusty NE
Fraser River outflow winds will ease across western Whatcom and
San Juan counties this afternoon. The focus now shifts to
overnight lows as they will be quite chilly. With clear skies and
lighter winds, Tuesday`s lows will drop into the lower to mid 30s
- mainly interior areas away from the sound. This will be the
coolest of the season so far and a Frost Advisory is in effect.
Wednesday morning temps will also be cool but the flow will turn
onshore during the day. Expect highs around 60 with clear skies
otherwise. 33
.LONG TERM /THURSDAY THROUGH SUNDAY/...Weak high pressure will
nudge inland on Thursday but some warm frontal precip may clip the
coast for a chance of light rain. A weak cold front will follow
Thursday night but overall QPF is light with just a few
hundredths. Showers will linger into Friday with ongoing onshore
flow. A wetter Pacific storm system is slated to move inland this
weekend (mainly on Sunday) for more rain, mountain snow, and
locally windy conditions. 33
&&
.AVIATION...Breezy northerly winds have materialized throughout
Puget Sound as ongoing Fraser outflow persists through western
Whatcom county. Gusts so far have been between 20 and 25 kts though
an occasional gust to 30 kt cannot be ruled out through 00Z-02Z.
Gusty NE winds will last longer near BLI into the overnight period.
Easing winds are expected later this evening, remaining northerly.
VFR cigs at all terminals this afternoon, likely to persist
throughout evening and into the overnight hours. There are a few
exceptions, as winds begin to ease and skies remain clear, fog is
likely in OLM and through portions of the Chehalis Valley tomorrow
morning.
KSEA...VFR and breezy this afternoon as northerly winds continue.
Gusts so far have been up to 25 kts, but a gust to 30 kt cannot be
ruled out through around 00Z. After 00Z, winds are expected to stop
gusting, though remain between 10-12 kts. NNE winds are expected
throughout the overnight period. With a northerly wind continuing
and keeping conditions a bit drier, confidence in any fog
development tomorrow morning is low despite clear skies.
21
&&
.MARINE...A low pressure system will continue to move southward
along the coast today, generating breezy northeasterly winds over
much of the area waters. Small Craft northerlies will continue over
the Puget Sound and over the outer coastal waters through the
afternoon before easing this evening, as well as through the Eastern
and Central Strait of Juan de Fuca through the early morning
Tuesday. High pressure will build over area waters through Thursday,
bringing light onshore flow and calmer conditions over the waters.
The next impactful system will arrive towards the end of the week
and into the weekend, with potential for widespread Small Craft
winds over the outer and inner waters.
Combined seas will continue to gradually decrease to 4 to 7 ft as
the day progress. Seas remain around 4 to 6 feet through midweek
before potentially rising above 10 ft towards the weekend.
15
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Wind Advisory until 2 PM PDT this afternoon for Lowlands of
Western Whatcom County-San Juan County.
Frost Advisory from 2 AM to 8 AM PDT Tuesday for Downtown
Everett / Marysville Area-Foothills and Valleys of Central
King County-Foothills and Valleys of Pierce and Southern
King Counties-Foothills and Valleys of Snohomish and
Northern King Counties-Foothills and Valleys of Thurston
and Lewis Counties-Foothills and Valleys of the North
Cascades-Lowlands of Lewis and Southern Thurston Counties-
Lowlands of Western Skagit and Northwestern Snohomish
Counties-Middle Chehalis River Valley-Olympia and Southern
Puget Sound-Southern Hood Canal.
PZ...Small Craft Advisory until 5 AM PDT Tuesday for Central U.S.
Waters Strait Of Juan De Fuca-East Entrance U.S. Waters
Strait Of Juan De Fuca.
Gale Warning until 2 PM PDT this afternoon for Northern Inland
Waters Including The San Juan Islands.
Small Craft Advisory until 11 PM PDT this evening for Northern
Inland Waters Including The San Juan Islands.
Small Craft Advisory until 5 PM PDT this afternoon for Admiralty
Inlet-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-Puget Sound and Hood Canal.
&&
$$
NWS SEW Office Area Forecast Discussion
Discussion Script by Ken True at Saratoga Weather - WFO Script by SE Lincoln Weather
