Small Craft Advisory 68, NWS Seattle, WA

Area Forecast Discussion
National Weather Service Seattle WA
330 PM PDT Sat Apr 7 2018

.SYNOPSIS...A strong low pressure system will affect the region
through Sunday morning. A high wind warning is in effect for the
central and south coast of Washington while wind advisories are
in effect for portions of the interior of Western Washington.
High pressure and offshore flow will bring some sunshine and warm
temperatures to the area Monday. Additional fronts will move
through the area Tuesday through Saturday.

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.SHORT TERM...High wind warnings are in effect for the central and
south coast, and wind advisories are in effect from about Everett to
Bellingham and out through the islands. Winds today in the Seattle
Tacoma metro area didn't amount to much, but it may yet get pretty
blustery tonight and Sunday morning as the low fills and shifts to
the north coast. The higher elevations of the mountains should pick
up some heavy wet snow--but it was still bare and wet this afternoon
at the Paradise Mt. Rainier parking lot--hopefully the snow level
will come down a little overnight. High pres builds into Western
Washington Sunday night into Monday morning and then low level flow
turns offshore as the high moves inland. Monday should be sunny with
highs in the 60s before another front nears the area for Tuesday.

.LONG TERM...A parade of fronts will keep the rest of the week wet
at times. The GFS shows fronts Tuesday and Wednesday, a trough
Thursday, a warm front Friday--with heavy rain on Vancouver Island,
and then a cold front Saturday. There are pretty decent low pres
systems associated with the frontal systems, but nothing as deep
and as close to us as the deep low sitting just offshore today.

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.AVIATION...A strong upper low out near 130W will gradually weaken
by the time it crosses Northwest Washington on Sunday morning.
Strong southwest flow aloft today will become moderate westerly
flow late tonight, then moderate northwesterly on Sunday
afternoon. The air mass will be moist and a little unstable
through Sunday. Cigs will generally come down this evening as a
drying easterly component to surface pressure gradients ends and
become onshore. Lots of showers from now through Sunday, reducing
visibility at times and obscuring the mountains.

KSEA...Cigs will come down this evening and overnight as surface
gradients gradually shift from a drying offshore component to a
moister onshore component. Cigs will drop below 020 late tonight.
Will have a hard time lifting much above 030 on Sunday afternoon.
Gusty S-SW wind continuing through Sunday. Haner

&&

.MARINE...A 975 mb low near 48N 130W this afternoon will
move east and fill to a 995 mb low by the time it reaches Cape
Flattery early Sunday morning. It will continue to quickly weaken
as it moves across Northwest Washington on Sunday. As a result,
strong southeast gradients this afternoon will weaken this
evening and become more southerly on Sunday.

High pressure will build into the waters on Sunday night then
shift east of the Cascades on Monday. A negatively tilted cold
front will cross 130W on Monday evening and then cross the waters
on Tuesday morning. Offshore low pressure will continue to support
south and southeast gradients on Wed and Thu.

&&

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.HYDROLOGY...Rain will transition to showers over the south slopes
of the Olympics this afternoon and tonight. With this fairly steady
influx of rainfall...the Skokomish river has been reacting with
water levels increasing as forecast. Current forecast still keeps
the river just under minor flood stage...but since it remains so
close...current flood watch looks good to remain intact. As for the
other rivers...will see river levels rise some as rainfall
continues...but flooding is unlikely over the next seven days. SMR

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Flood Watch through Sunday morning for Hood Canal Area-Lower
     Chehalis Valley Area-Olympics.

     Wind Advisory until midnight PDT tonight for Admiralty Inlet
     Area-Everett and Vicinity-San Juan County-Western Skagit
     County-Western Whatcom County.

     High Wind Warning until 11 PM PDT this evening for Central Coast.

     High Surf Advisory until 9 AM PDT Sunday for Central Coast-North
     Coast.

     Wind Advisory until 11 PM PDT this evening for North Coast.

PZ...Small Craft Advisory for rough bar until 9 PM PDT Sunday for
     Grays Harbor Bar.

     Gale Warning until 6 AM PDT Sunday for 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.

     Gale Warning until 10 PM PDT this evening for Admiralty Inlet-
     Central U.S. Waters Strait Of Juan De Fuca-Coastal Waters
     From Cape Flattery To James Island 10 To 60 Nm-Coastal
     Waters From Cape Flattery To James Island Out 10 Nm-Puget
     Sound and Hood Canal.

     Gale Warning until 5 AM PDT Sunday for East Entrance U.S. Waters
     Strait Of Juan De Fuca-Northern Inland Waters Including The
     San Juan Islands.

     Small Craft Advisory until 6 PM PDT Sunday for West Entrance
     U.S. Waters Strait Of Juan De Fuca.

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