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000
FXUS66 KSEW 141259
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
559 AM PDT Sun Apr 14 2024

.SYNOPSIS...Weak high pressure overhead on Sunday before upper-
level troughing returns on Monday. With it cooler temps and
showers are slated to return. However, more ridging is likely
later in the upcoming week with the potential for more warm and
dry weather.


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.SHORT TERM /TODAY THROUGH TUESDAY/...
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We`ll see one last dry day
on Sunday well, at least in the short term. The upper-level
pattern is virtually unchanged with quasi-zonal flow over much of
BC and an upper-level low over CA. In between, the PNW remains
with weak high pressure. We`ll again see above average
temperatures throughout much of the interior. Highs will top out
in the lower to mid 60s with coastal areas remaining in the 50s.
Notably, models have a stout 1032mb surface high offshore
gradually tracking eastward. With lower pressure inland, strong
onshore flow will develop throughout the day before peaking in the
evening. A westerly push looks to bring 30-40 mph gusts to
Whidbey Island before decreasing overnight. Weak ridging will be
replaced by subtle troughing Sunday night. Nighttime lows are to
range between the lower to mid 40s.

As advertised, the pattern will flip on Monday as showers and
cooler temps return via upper-level troughing. Previous 60s
experienced on Sunday will be replaced by 50s. Lower snow levels
are in the offing as well with values hovering around 2,000 ft by
Monday night. A few inches of snow can`t be ruled out for the
passes. Models have troughing hanging on into Tuesday with
straggling showers. Most are to be in the confines of the
mountains through aid of orographic lifting. Another day of
widespread 50s are in the forecast with overnight lows in the 30s,
possibly near freezing around the South Sound and foothills
Tuesday night.

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...Conditions are
continuing to trend drier again midweek onward. Deterministic
guidance continues to hint at a ridge amplifying around Wednesday-
Thursday and lasting towards the weekend. But, questions remain on
its exact location and intensity. Nevertheless, the brief cool
down to start the week on Monday may not last too long as temps
could possibly top out in the upper 60s to near 70 F on Friday.
Ahead, much uncertainty is present this far out, but a weak front
could brush the area on Saturday.

McMillian
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.AVIATION...VFR with passing high clouds. Onshore flow this morning
may result in lowering cigs along the coast, generally MVFR/IFR
range with a 75% chance at HQM between 12-19Z this morning. In
addition, stratus may again develop in Puget Sound, although
confidence is low in this occuring (less than 30%). Patchy fog may
also occur, particularly towards western Whatcom County. Mainly VFR
again Sunday afternoon. Light north to northwest winds will increase
back to 5 to 10 kt out of the west-northwest this afternoon, and 8
to 12 kt at CLM and HQM.

KSEA...VFR cigs with high clouds at times into tonight. Another
round of stratus may be possible again Sunday morning, however
confidence is low, with generally a 15-20% chance of IFR cigs. North-
northeasterly winds 5 kt or less tonight turning to the northwest 5
to 10 kt after 17Z Sunday morning.

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.MARINE...High pressure will continue through the weekend with Small
Craft Northwest winds along the coastal waters through Sunday. Winds
will then increase with a frontal system Sunday evening into Monday,
particularly for the Strait of Juan de Fuca and adjacent interior
waters, including Admiralty Inlet and the Northern Inland Waters. A
Gale Warning has been issued for the central and eastern Strait of
Juan de Fuca with the increasing west winds. Northwest winds will
continue to remain breezy into Monday for the Coastal Waters with
this system. Winds will likely weaken Monday morning before
increasing once again Monday evening through the Strait of Juan de
Fuca with another round of gales possible Monday evening into Monday
night. Winds look to ease Wednesday into Thursday with building high
pressure over the area waters.

Seas will remain 9 to 12 feet through Monday with the highest waves
over the northern Coastal Waters. Waves will also be steep into
Sunday with a 9 to 10 second period. Seas will begin to subside
Tuesday and further Wednesday towards 4 to 6 feet.

15


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.HYDROLOGY...No river flooding is expected through the next seven
days.


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.SEW WATCHES/WARNINGS/ADVISORIES...
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WA...None.
PZ...Small Craft Advisory from 11 AM this morning to 7 AM PDT Monday
     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-West Entrance U.S. Waters Strait Of
     Juan De Fuca.

     Gale Warning from 1 PM this afternoon to 7 AM PDT Monday for
     Central U.S. Waters Strait Of Juan De Fuca-East Entrance
     U.S. Waters Strait Of Juan De Fuca.

     Small Craft Advisory until 7 AM PDT Monday 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.
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