Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
083
FXUS66 KSEW 050931
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
231 AM PDT Mon Oct 5 2026
.SYNOPSIS...
Near-zonal flow aloft and onshore flow at the surface will
maintain seasonable conditions across western Washington through
much of the week, with morning clouds and afternoon sun breaks.
Chances for rain increase towards the end of the week alongside
cooler temperatures as troughing develops over the Pacific
Northwest.
&&
.SHORT TERM /TODAY THROUGH WEDNESDAY/...
An upper level ridge over the Great Basin has weakened and
flattened, allowing for zonal flow to develop aloft over the
Pacific Northwest with a return to onshore flow at the surface.
The pattern is set to remain steady throughout the short-term,
resulting in little change day to day through Wednesday. Daily
marine pushes will result in expanding stratus across the
lowlands each morning, with potential for patchy fog to develop
in fairly stagnant overnight conditions. The fog and stratus
will erode for most lowland areas by the afternoon each day,
although areas along the coast may stay socked in with little
sunshine. The cooler marine air will allow for seasonable fall
temperatures, with highs generally in the 60s to lower 70s, and
lows in the mid 40s to lower 50s. The upper level ridge over the
southwestern US will rebound slightly on Wednesday, resulting in
little more than temperatures a degree or two warmer across the
region.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
The upper level high pressure ridge over the southwestern US
will continue to nudge into the Pacific Northwest slightly on
Thursday, resulting in continued warming with high temperatures
in the mid 60s to lower 70s. However, conditions on Thursday will
feel similar to past days with another potential round of low
stratus in the morning and sunny skies in the afternoon.
Forecast models remain in good agreement of troughing developing
over the region on Friday into the weekend, but the details
still remain fairly uncertain. Models have continued to back off
on incoming rainfall on Friday with a frontal system splitting
as it moves into western Washington, though ensembles hint at a
potential Puget Sound convergence zone developing into Saturday.
A cutoff low is also expected to develop overhead by Saturday,
bringing cooler temperatures and chances for light showers
lingering into Sunday. The exact details remain uncertain at
this time, but next weekend looks to be cooler and unsettled
with highs peaking in the mid 50s to lower 60s.
15
&&
.AVIATION...
Upper-level ridging has flattened and leading to quasi-zonal flow.
West to west-southwest winds aloft with onshore in the lower levels.
Patchy fog and low clouds are currently developing across the area
so far this morning. This activity will become widespread cross the
interior and portions of the coast with IFR/LIFR cigs and vis. VFR
conditions are slated to return by 19-22z. An additional round of
low clouds/fog is in store overnight Monday into Tuesday morning as
low-level onshore flow persists.
KSEA...VFR as of 0930z but fog/low clouds will spread across the
terminal by 12-14z with IFR/LIFR conditions and remain in place
throughout the morning. VFR skies are to return by 18-20z and last
for the remainder of the day. An additional round of low clouds/fog
is in store overnight Monday night into Tuesday morning with
continued low-level onshore flow. Light winds this morning before
northerly this afternoon 4-8 kt.
41
&&
.MARINE...
Onshore flow has returned into today as low pressure shifts
inland and surface high pressure builds offshore. However, the
current SCA over the central/eastern strait will be allowed to
expire this morning. Westerly pushes are favored throughout the
upcoming week of varying strength. A more organized system
appears favorable towards Friday with a better chance of
widespread headlines.
41
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 5 AM PDT early this morning for
Central U.S. Waters Strait Of Juan De Fuca-East Entrance
U.S. Waters Strait Of Juan De Fuca.
&&
$$
NWS SEW Office Area Forecast Discussion