Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

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FXUS66 KSEW 191009
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
309 AM PDT Tue Oct 19 2021

.SYNOPSIS...Quiet weather will remain in place for Tuesday with
slightly warmer than average temperatures today and morning fog. A
noticeable shift towards active weather will occur Wednesday as a
series of systems make their way through Western Washington.
These systems will bring widespread rain, some breezy to windy
conditions to the area as well as high mountain snow.

&&

.SHORT TERM /TODAY THROUGH THURSDAY/...Areas of morning fog this
morning with temperatures in the 30s to low 40s for the
lowlands. High temperatures will be slightly on the warmer side of
seasonable with highs in 60s for the area. Tuesday night and the
start of Wednesday will remain a bit mild but a cold front that
will be moving through will cool everything down to more
seasonable temperatures by late in the day. The cold front is
associated with a low that will be moving inland well to our
North. While we will not be feeling the impacts from the low we
will experience increased winds as well as widespread rain.
Southerly winds will begin to pick up during the early morning
hours by the coast and then late morning to early afternoon for
the interior. The windy areas of the coast, and along the Northern
Inland Waters (San Juans, W Whatcom/Skagit, Island Counties) will
likely see gusts of around 25-30 mph. Elsewhere in the interior
gusts will be noticeably lower and in the 15-20 mph range.
Looking at the rain the heaviest is expected to occur in the
Southern Olympics with 1-2 inches expected to fall over the course
of the day. Considerably less rain is expected elsewhere with the
North Cascades expecting 0.5-1 inch for the same time period.
Rain will taper off and winds will ease late Wednesday night/early
Thursday morning as we have a small break between approaching
systems. The next frontal system will begin its approach towards
Western Washington Thursday afternoon. This will once again create
for breezy and wet conditions area wide. That said Thursday`s
temperatures will be on the warm side due to the warm front
associated with the low that moves through the area early in the
day.

Butwin

.LONG TERM /FRIDAY THROUGH MONDAY/...If you were unsure if fall
had arrived this weekend will surely bring an end to that thought.
Multiple systems will track their way through the area that will
keep the weather in Western Washington rather unsettled. Breezy
winds and widespread rain are expected throughout the weekend and
into early next week. Snow levels will be dropping down to
4500-5000 feet on Sunday and have the potential to drop a little
lower for Monday. This will give the high elevations of the
mountains another round of snow. At this time confidence is low on
whether or not snow will be accumulating on any of the passes,
but there is the potential.

Butwin

&&

.AVIATION...Southerly flow aloft will increase today and tonight
then become westerly Wednesday. At the surface, weak high
pressure over the area will give way to gradually increasing
easterly flow today as an offshore frontal system approaches. The
front will move through the area Wednesday. Ceilings around 4000
feet in the central Puget Sound until 16-18z. Areas of fog with
ceilings below 200 feet and visibility below 1/2 mile from about
Tacoma southward until 18z. Elsewhere and this afternoon and
tonight just some high clouds. Ceilings lowering to 3500-4500 feet
Wednesday morning.

KSEA...Ceilings around 4000 feet until around 17z then just some
high clouds. Light wind becoming northwest 4 to 8 knots midday.

Felton

&&

.MARINE...Weak high pressure over the inland waters will move east
today. A series of vigorous frontal systems will move through the
area every 24 to 36 hours with the first one on Wednesday followed
by another one Thursday and again Saturday. Each system will
bring small craft advisory strength southerly winds to most
waters with gale force winds for the Coastal Waters.

West to southwest swell will build to 10-13 feet over the Coastal
Waters and West Entrance Strait of Juan de Fuca Tuesday night and
remain elevated for most of the rest of the week.

Felton


&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 2 PM PDT this afternoon 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-Coastal Waters From Point Grenville To Cape
     Shoalwater 10 To 60 Nm.

     Gale Warning from 2 PM this afternoon to 11 AM PDT Wednesday 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-Coastal Waters From Point Grenville To Cape
     Shoalwater 10 To 60 Nm.

     Small Craft Advisory from 5 AM early this morning to 5 AM PDT
     Wednesday 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 Out 10 Nm.

     Gale Watch from Wednesday morning through Wednesday afternoon
     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 early this morning to 5 PM PDT
     this afternoon for West Entrance U.S. Waters Strait Of Juan
     De Fuca.

&&

$$

www.weather.gov/seattle


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