Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

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000
FXUS66 KSEW 052345
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
345 PM PST Fri Mar 5 2021

.SYNOPSIS...An upper trough will slide east across the area
tonight. Another front will move through Sunday as an upper low
slides south along the west coast. Drier weather Monday into next
week as the bulk of the energy with the upper low slides into
California. Light precipitation possible Thursday as a system
approaches the area.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY/...The bulk of the steady
precipitation has slid east of the area this afternoon with
showers around over the Olympics and into the Pacific. A band of
heavier rain showers across the Puget Sound will slide east this
afternoon. Small hail, gusty winds, and lightning is possible
with this activity. Otherwise, showers will be around tonight into
Saturday as an upper trough moves through, however, most
locations will likely be drier for most of the time. Temperatures
this afternoon in the upper 40s to low 50s.

The next round of steadier precipitation will move through
Saturday night into Sunday morning as a front weakens over the
area with an upper low located over the NE Pacific. The bulk of
the energy with this system will slide south of the area Sunday
into Monday with most precipitation tapering off by Sunday night.
Sunday may feature the best chance for any convection, mainly
along coastal areas, with a bit more instability located over
these areas. Some moisture may be around into Monday, but most
guidance highlights the coast and areas of the Olympic Peninsula
for any rain through Monday. Temperatures will be a bit cooler
over the weekend into early next week with highs in the upper 40s
to low 50s.

.LONG TERM /TUESDAY THROUGH FRIDAY/...Mainly dry weather Tuesday
and Wednesday for the area, though some guidance suggests light
precipitation may be around in spots Tuesday with the upper low
south of the area. The next system looks to approach the area on
Thursday, though there is some differences in guidance. ECMWF
ensembles highlight a bit more ridging on Thursday compared to
other guidance, which would keep for a drier forecast. Either way,
some light precipitation may be around Thursday with perhaps the
better chance for rain Friday into the weekend. Morning
temperatures may be on the cooler side with lows in the mid to
upper 30s through Wednesday, highs in the low to mid 50s through
the week. JD

&&

.AVIATION...Rain has turned more showery across the area this
afternoon in the wake of a frontal system that moved through the
region this morning. Southwesterly winds will persist aloft as
upper level troughing remains the dominant influence across the
northeastern Pacific and the Pacific Northwest. Ceilings and
visibilities have rebounded back to VFR at most area TAF sites,
however MVFR and IFR conditions will still be possible in heavier
showers. Thunderstorms will be possible for terminals through
this evening as the airmass becomes increasingly unstable in the
post-frontal airmass. Surface winds have started to ease across
the area this afternoon, but will continue to remain breezy
through this evening, especially in heavier showers and any
thunderstorms that do develop along the coast.

KSEA...Southerly winds, generally between 8-15 knots. Winds have
started to ease this afternoon and will continue to ease into this
evening. Showers will be possible vicinity of the terminal
through the evening. Conditions expected to be primarily VFR, but
could drop to MVFR or even IFR should any heavier showers pass
across the terminal. 14

&&

.MARINE...Elevated winds and seas will continue across area waters
into Saturday in the wake of a vigorous cold front. Gusty winds
have started to ease this afternoon, however will remain rather
breezy through the evening before subsiding.

Meanwhile, offshore swells remain elevated, primarily between
10-13 feet for the nearshore waters and 13-19 feet across the
offshore waters this afternoon. Seas will gradually subside late
tonight into Saturday, but are expected to remain above 10 feet,
before another large swell train (18-21 feet) arrives in the
region by Sunday afternoon.

A number of marine headlines continue for area waters this afternoon
and into this evening--including offshore gale warnings and small
craft advisories for the majority of the inland waters (except the
Northern Interior and the Eastern Strait where a gale warning
remains in effect). Will see a brief break in the winds on Saturday,
before another round of marine headlines with the next system
moving into the region Saturday night into Sunday. 14

&&

.HYDROLOGY...Steady rain has become scattered showers with
activity into Saturday. Although the Skokomish River continues to
rise, the heaviest rainfall has ended, and other rivers in the
basin have crested. The Flash Flood Watch has been ended for Mason
County. Rainfall will continue periodically through the weekend,
however river flooding is not expected. JD

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Gale Watch from Saturday afternoon through late Saturday night
     for 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.

     Small Craft Advisory from 10 PM this evening to 10 AM PST
     Saturday for 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.

     Gale Warning until 10 PM PST this evening for 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.

     Small Craft Advisory until 4 PM PST Saturday for Grays Harbor
     Bar.

     Gale Watch from Saturday evening through late Saturday night for
     East Entrance U.S. Waters Strait Of Juan De Fuca-Northern
     Inland Waters Including The San Juan Islands.

     Small Craft Advisory from 1 AM to 7 AM PST Saturday for East
     Entrance U.S. Waters Strait Of Juan De Fuca-Northern Inland
     Waters Including The San Juan Islands.

     Gale Warning until 1 AM PST Saturday for East Entrance U.S.
     Waters Strait Of Juan De Fuca-Northern Inland Waters
     Including The San Juan Islands.

     Small Craft Advisory until 10 AM PST Saturday for West Entrance
     U.S. Waters Strait Of Juan De Fuca.

     Small Craft Advisory until 4 AM PST Saturday for Central U.S.
     Waters Strait Of Juan De Fuca.

     Small Craft Advisory until 7 AM PST Saturday for Admiralty Inlet-
     Puget Sound and Hood Canal.

&&

$$

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