Flood Watch 19, NWS Seattle, WA

Area Forecast Discussion
National Weather Service Seattle WA
251 AM PST Fri Nov 25 2016

.SYNOPSIS...There will be a break in the wet weather today, with
an upper trough bringing more rain and mountain snow late tonight
and Saturday. After another break on Sunday, a generally wet
pattern will resume Sunday night and continue through midweek.

&&

.SHORT TERM...Today will be mainly dry in the wake of a front.
Winds are currently easing and snow in the mountains is tapering.
Some showers will linger today, mainly over the mountains.

A frontal system will spread rain into the area from the south
tonight. There will also be another round of snow for the
mountains - highest for the volcanoes where advisory amounts look
likely. The GFS is bringing a fairly deep low right across
Western Washington Saturday morning which would suggest a wind
event. However, all other models are much weaker. The GFS is being
discounted again for now. It will likely be a bit breezy.

An upper trough will be over the area on Saturday with showers
likely. High pressure aloft will move over the area Sunday for a
mainly dry day but the next frontal system will already be
spreading rain in from the west late in the day. Schneider

.LONG TERM...A frontal system will exit the area early Monday with
decreasing showers. Another wet front will reach the area later
Tuesday or Tuesday night. Models are a bit out of sync with the
timing. Showers will follow on Wednesday. Thursday should be a
relatively dry day in between weather systems. Schneider

&&

.AVIATION...A front moved through Western Washington overnight
and the rain finally turned to scattered showers. The air is
moist and somewhat unstable. Another frontal wave will move up
from the south tonight for periods of rain, and then Saturday
should be showery and cool behind the front.

KSEA...The front finally cleared the area overnight and today
should just see scattered showers and a light southerly wind that
becomes light and variable and perhaps northerly late in the day.

&&

.MARINE...Weaker systems will affect the area through the
weekend. The best chance of small craft advisory conditions will
be over the coastal waters and at the west entrance to the Strait
of Juan de Fuca. A cold front will move through the area Sunday
night.

&&

.HYDROLOGY...The Skokomish river in Mason county will remain
slightly above flood stage today and then recede below flood
stage tonight or Saturday morning.

Heavy rains over the last 24 hours has pushed several rivers in
the south sound to within a foot or two of flood stage early this
morning. The heavy rains ended a few hours ago but rivers are
still rising. Current forecasts are for all rivers to crest below
flood stage but it will be close for some and flood warnings may
be needed later this morning.

Elsewhere river flooding is not expected in the next 7 days.

A recent period of heavy weather has left area soils saturated
and very wet. USGS soil wetness indices suggest isolated
landslides are possible in favored locations.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Winter Storm Warning until 4 AM PST early this morning for
     Cascades of Pierce and Lewis Counties-Cascades of Snohomish
     and King Counties-Cascades of Whatcom and Skagit Counties-
     Olympics.

     Wind Advisory until 4 AM PST early this morning for Admiralty
     Inlet Area-San Juan County-Western Whatcom County.

PZ...Small Craft Advisory for rough bar until 3 AM PST Saturday for
     Grays Harbor Bar.

     Small Craft Advisory until 3 AM PST Saturday for 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-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-West Entrance U.S. Waters Strait Of Juan De Fuca.

     Gale Warning until 3 AM PST early this morning for Admiralty
     Inlet-East Entrance U.S. Waters Strait Of Juan De Fuca-
     Northern Inland Waters Including The San Juan Islands-Puget
     Sound and Hood Canal.

&&

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