Sandy Hook Park, Washington Weather Forecast Discussion

610
FXUS66 KSEW 181651
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
951 AM PDT Thu Sep 18 2025
.SYNOPSIS...Onshore flow will maintain near normal temperatures
across western Washington with morning clouds and afternoon sun
breaks. The next system will arrive on Saturday, bringing
widespread rain and breezy winds to the region. Conditions will
dry out early next week as high pressure builds into the region.
&&
.SHORT TERM /TODAY THROUGH SATURDAY/...The current forecast
remains on track with no planned updates this morning. 33
Previous discussion...Cooling will continue today as onshore
flow strengthens, with temperatures peaking in the 60s to low 70s
across the region. While conditions will stay dry, marine stratus
will continue to expand inland this morning and erode by the
afternoon to reveal mostly clear skies. However, wildfire smoke
will continue to impact the region, most notably near the Bear
Gulch fire in the Olympics. As weak troughing moves over the area
today, winds overhead will shift northerly, which will direct the
smoke southward towards Shelton and southward along the I-5
corridor. Areas in the Cascades can also expect to see hazy skies
due to wildfire smoke throughout the day.
Weak ridging will build into the region on Friday, bringing an
additional day of more of the same. Temperatures will peak a few
degrees above normal, with another round of morning stratus,
afternoon sun, and areas of smoke.
The next weather system will move into the region on Saturday as a
cold front moves inland. Rain will reach the coast by the
afternoon, filling inland by the late evening. As the cold front
swings across western Washington, winds will become breezy with
gusts reaching 20 to 30 mph.
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...An upper level trough will
continue to dig into the region on Sunday, maintaining unsettled
weather through the weekend. The bulk of the moisture will fall
overnight into Sunday morning, with lingering showers over the
mountains Sunday afternoon. Ensembles remain fairly steady over
rainfall estimates through Sunday, with a third to half an inch of
rain over the lowlands and up to 2 inches over the Olympics and
Cascades.
Ridging will build into the region to start off next week, with
some uncertainty over potential precipitation. Operational models
continue to dry things out through Wednesday, while ensembles
maintain a chance for rain along the northern Olympic Peninsula
and northern interior Monday with another incoming system on
Wednesday. Temperatures are on track to stay on the mild side
through the period.
15
&&
.AVIATION...Southwesterly flow becoming northwesterly tonight as an
upper level trough moves across the area. VFR conditions for the
majority of the interior terminals, with the exception of BLI.
Improvement expected after 19Z. IFR/LIFR continues along the coast
this morning, but expect clearing after 19Z as well. VFR will
prevail for the rest of today after improvement. Guidance is hinting
at another round of low stratus for the coast and fog-prone
locations again tomorrow morning as we begin to get more subsidence
and weaker winds over the region. Northwesterly to northeasterly
winds today at 8 to 12 kt. This should keep the smoke away from CLM,
but could introduce it near SHN and OLM.
KSEA...VFR conditions this morning at the terminal and will prevail
for the rest of today. Mostly clear skies with high clouds today.
Northeast winds around 5 kt this morning will shift to the north-
northwest this afternoon/evening and increase to 8 to 12 kt. Winds
will shift back northeasterly late tonight after 3Z-4Z at 4 to 6 kt.
62/29
&&
.MARINE...High pressure will rebuild over the coastal waters today
and into Friday. Another cold front will increase winds and bring
rain to the area waters this weekend. Southwesterly winds will
increase across the entire area, but the best chances for seeing
Small Craft Advisory level winds will be through the central
portions of the Strait of Juan de Fuca, from Saturday afternoon as
the front moves though, and behind the front, through much of
Sunday. Winds may briefly hit SCA criteria for a few hours as the
front moves through the interior waters from the Puget Sound up
through the northern interior waters. Winds look to ease on Monday
through additional systems may approach the waters next week.
Seas are sitting around 8 to 10 ft across the waters this morning,
but should slowly decrease this morning as winds also ease below
Small Craft Advisory criteria. The advisory will continue through
this afternoon, primarily for the outer coastal waters. Seas
decrease to 6 to 8 ft tonight, becoming 4 to 5 ft Friday. Seas will
once again bump up to 7 to near 10 ft this weekend as the frontal
system moves through. Seas return to 6 to 8 ft next week.
62
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 5 PM PDT this afternoon 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