Clinton, Washington Weather Forecast Discussion

669
FXUS66 KSEW 012118
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
218 PM PDT Wed Oct 1 2025
.SYNOPSIS...An unstable air mass associated with an upper level low
pressure off the coast will lead to showers and isolated
thunderstorms today. A weakening trough over the region will keep
conditions unsettled through Thursday. A trend toward drier weather
will begin over the weekend as a ridge of high pressure aloft builds
offshore.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...An upper level low will
continue to spin offshore into Thursday with bands of showers
rotating around it into Western Washington. The low will gradually
weaken with time and shower coverage will wane later tonight into
Thursday. The low will fill and eventually move onshore over Oregon
Thursday night. Mostly dry conditions are expected on Friday with
temperatures returning to around seasonal norms. High amplitude
ridging starts to build well offshore around 145W on Saturday while
broad upper troughing takes up residence over the Northern Rockies.
A weak disturbance diving southward through British Columbia may
clip the region on Saturday, but chances of any precipitation of
note look minimal.
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...By the early portion of
next week, the offshore mean ridge position is expected to gradually
progress closer to around 135W and exert a greater influence on the
region. Ensembles continue to struggle somewhat with the development
of a possible Rex Block pattern over the Western US by Tuesday.
Nonetheless, an upper ridge is expected to become the dominant
player for Western Washington for the first half of next week with a
period of offshore flow nudging temperatures closer to or a little
above normal for early October. 27
&&
.AVIATION...Southwest flow aloft will continue into Thursday as an
upper level low offshore moves towards Western Washington. VFR cigs
this afternoon for the majority of the area, with lingering MVFR
cigs along the coast and in heavier showers. VFR conditions will
continue for most areas through this evening, with cigs lowering to
MVFR tonight into Thursday morning for the coast. Showers will
continue into tonight, particularly for the Olympic Peninsula
overnight. In addition, there remains a 15 to 25% chance of
thunderstorms through this evening embedded within any heavier
shower, with thunderstorm chances mainly confined to the coast
tonight into early Thursday. Southerly winds will remain breezy at
times near the water through tonight, before slowly tapering
Thursday afternoon.
KSEA...VFR conditions this afternoon with continued mid clouds.
Periodic showers will continue into this evening (primarily through
03z) before predominantly drier conditions tonight. Will need to
continue to monitor any thunderstorm with a heavier shower, but
confidence remains low in this occurring. Otherwise, VFR conditions
with mid clouds are expected into Thursday morning. MVFR
probabilities Thursday morning remain low, peaking at 15%. South
winds into Thursday, with occasional gusts near 20 kts this
afternoon. JD
&&
.MARINE...Southerly winds will continue to remain elevated through
tonight with a weather system situated offshore. Gales will continue
at times for the Coastal Waters, as well as the eastern Strait of
Juan de Fuca and northern inland waters through tonight. SCA wind
gusts at times elsewhere. Winds will slowly dissipate throughout the
day on Thursday. A Small Craft Advisory has been issued following
the gales on Thursday for the Coast, as well as portions of the
interior waters as winds slowly subside. The aforementioned frontal
system will weaken later Thursday into Friday, resulting in lighter
winds late in the week. Winds look to transition more northerly
later in the weekend into early next week.
There also remains a 15 to 25% chance of thunderstorms into
Thursday, especially for the Coastal Waters. Showers and
thunderstorms may be accompanied by stronger winds and small hail
over the Coastal Waters.
Combined seas of 15 to 20 feet will continue through this evening.
Seas will slowly subside below 15 feet Thursday morning, and further
subside below 10 feet by Thursday evening. Seas of 4 to 6 feet are
expected Friday into the weekend. JD
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...High Surf Advisory until 5 AM PDT Thursday for Grays Harbor
     County Coast-Northern Washington Coast.
Wind Advisory until 5 AM PDT Thursday for Island County.
PZ...Small Craft Advisory until 5 PM PDT Thursday for Grays Harbor
     Bar.
Small Craft Advisory until 5 AM PDT Thursday for Admiralty Inlet-
     Central U.S. Waters Strait Of Juan De Fuca-Puget Sound and
     Hood Canal-West Entrance U.S. Waters Strait Of Juan De Fuca.
Gale Warning until 5 AM PDT Thursday 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-East Entrance U.S. Waters Strait Of
     Juan De Fuca-Northern Inland Waters Including The San Juan
     Islands.
Small Craft Advisory from 5 AM to 2 PM PDT Thursday for East
     Entrance U.S. Waters Strait Of Juan De Fuca-Northern Inland
     Waters Including The San Juan Islands.
Small Craft Advisory from 5 AM to 5 PM PDT Thursday 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.
&&
$$

NWS sew Office Area Forecast Discussion