Preachers Slough Washington Weather Forecast Discussion

895
FXUS66 KSEW 102154
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
254 PM PDT Fri Oct 10 2025
.SYNOPSIS...Seasonally cool and unsettled conditions will settle across
western Washington through the weekend into early next week.
A system moving southward from British Columbia Sunday will
bring the first noteworthy high elevation snow of the season.
Drier conditions will return toward the middle of next week as
high pressure rebuilds over the region.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...Periods of showers
will continue to affect much of western Washington this evening.
It does look like the heavier band of precipitation that the
high resolution ensembles have been showing moving through the
metro area this afternoon is actually keeping to the east of the
Cascades. Guidance consistently showing a break in the
precipitation tonight with another organized band with the front early
Saturday morning. Behind this will likely be another dry break
for most areas except the Cascades until early Sunday morning.
An upper level shortwave moving southward through British
Columbia will start to push precipitation back into Washington
from the north - with lowering snow levels. Heaviest
precipitation looks to be over the Cascades of Whatcom and
Skagit Counties Sunday - with snow levels starting around 4300
feet and lowering to around 2200 feet by early Monday morning.
NBM continues to highlight 60-75% chance of 8 inches or more
above 5000 feet over the northern Cascades, and a winter
weather advisory has been issued for the northern Cascades to
reflect the early season accumulations at high elevations.
Precip amounts taper off through the Cascades from Snohomish
County southward - with snow levels running about 1000 feet
higher than the northern Cascades. This will mean accumulations
will be generally less and limited to the highest elevations
along the crest of the Cascades and Mount Rainier. Stevens pass
may be the only pass that gets any accumulation 60-70% chance of
1 to 2 inches through the day Sunday. Even at Snoqualmie Pass,
where accumulations are not expected, there`s still the
likelihood of periods of snow mixed in with rain. Those that
plan to head to the higher mountain elevations this weekend
should be prepared to encounter snow and cold conditions and
closely monitor the weather forecast in the next few days.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...Ensemble guidance
continues to favor the upper low over Oregon ultimately digging
into California. This will pull precipitation away from the
the Pacific NW and a drier pattern towards mid week. There
remains elevated concern for morning frost Monday and Tuesday
as clearing skies and light winds yield efficient cooling and
temperatures may reach the mid to upper 30s for the sheltered
interior locations away from the water. After a few dry days,
guidance favors a return of a more active pattern, and
associated precipitation chances, late in the week.
&&
.AVIATION...Southeasterly to southerly flow aloft as an upper
level low remains offshore. VFR conditions this afternoon with
showers moving northward. Ceilings will likely remain VFR
throughout the remainder of the evening but will slowly lower to
MVFR by Saturday morning across most of the area terminals. Bands
of showers will continue into the evening and could lower
terminals down to MVFR in heavier showers. Surface winds remaining
southerly around 5 to 10 knots.
KSEA...VFR conditions this afternoon with light showers in the
vicinity. Ceilings are leaning towards remaining VFR throughout
the evening before lowering to MVFR overnight and into Saturday
morning. A shower or two may go over the terminal but ceilings
look to remain VFR. Southerly winds look to remain around 4 to 8
knots throughout the TAF period.
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&&
.MARINE...High pressure will build in temporarily over the area
waters on Saturday between weather systems. Winds will be elevated
over the outer coastal waters, with a gale warning now posted from
Saturday morning through Sunday morning. Winds over the interior
waters will remain below thresholds, with the only exception being
possible Small Craft Advisory level westerly winds through the
Strait of Juan de Fuca late Saturday night into Sunday morning. As
another low pressure system approaches the coast on Sunday, winds
will turn offshore, with a stronger gradient through the Strait of
Juan de Fuca expected. These winds are suggestive of potential
gales, but will let subsequent forecast details evolve before
making a determination.
Seas on Sunday will rise to 12-15 feet, which can create hazardous
beach conditions. Recreators on coastal Washington beaches should be
attentive to the ocean conditions and stay tuned to the forecast.
Winds will also be elevated, primarily along coastal Grays Harbor
County on Sunday. Winds will also pick up out of the northeast late
Sunday into Monday for western Whatcom county and the northern
interior waters.
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&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Winter Weather Advisory from 5 AM Sunday to 5 AM PDT Monday
     for Cascades of Whatcom and Skagit Counties.
PZ...Small Craft Advisory from 5 PM Saturday to 2 PM PDT Sunday for
     Coastal Waters From Cape Flattery To James Island Out 10
     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.
Gale Warning from 8 AM Saturday to 2 PM PDT Sunday 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.
&&
$$

NWS SEW Office Area Forecast Discussion