045
FXUS66 KSEW 142058
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
158 PM PDT Tue May 14 2024

.SYNOPSIS...Dry northwest flow aloft will continue through early
Thursday as high pressure builds offshore. An upper trough will
dip southward on Thursday from British Columbia, bringing cooler
temperatures and periods of precipitation mainly over the
mountains. Unsettled conditions are favored to persist into early
next week with cooler temperatures and chances for light showers
over higher terrain.

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY/...High pressure aloft will
continue to build off the Pacific coast through Wednesday,
allowing for dry northwest flow over western Washington. Onshore
flow will bring in passing high clouds with temperatures today
peaking near the 70 degree mark for much of the lowlands. High
pressure will build towards the Pacific Northwest on Wednesday,
allowing for the drying and warming trend to continue. Most areas
will see a few more degrees in warming with most Puget Sound
lowlands peaking in the mid 70s.

The pattern will shift on Thursday as an upper level trough drops
southward from British Columbia on Thursday. A cold front will
cross the region throughout the day, bringing in breezy winds, a
round of precipitation, and cooler temperatures. The bulk of the
moisture with this system will be focused over the Northern
Cascades with minimal accumulations elsewhere. Snow levels will
drop to 4000 ft by early Friday morning, though any snow
accumulations will be light and will be limited to the highest
peaks. The upper trough axis will swing across the Pacific
Northwest on Friday, maintaining breezy conditions and light
shower activity over the mountains. Temperatures will dip slightly
below normal on Thursday and Friday with most areas seeing highs
in the low to mid 60s.

.LONG TERM /SATURDAY THROUGH TUESDAY/...Forecast confidence
decreases heading into the weekend with ensembles continuing to
show a wide range of solutions. Forecast models highlight the
potential for troughing through the extended, favoring slightly
below normal temperatures and periods of cloudy skies and light
precipitation over higher terrain.

Lindeman

&&

.AVIATION...High pressure/riding over the Pacific will continue to
build off coast, with flow as a result remaining northwesterly
through the forecast. Pushes through the Strait of Juan de Fuca has
resulted in diffluence with winds splitting to the southwest (north
of the east entrance), and north/northwest (south of the east
entrance). Winds this afternoon will max out at 5 to 10 kt (gusting
to 15 kt). Tonight, expect more northeasterlies at or under 5 kt
with a few terminals having variable winds.

Ceilings are expected to remain VFR through tonight (with a few
cumulus and high cirrus). A marine push tomorrow morning may result
in low-end VFR/high-end MVFR cloud decks reaching as far as west
Puget Sound Wednesday morning. Confidence remains low east of
stratus reaching east of Kitsap at this time.

KSEA...VFR conditions through tonight with high cirrus/few cumulus
clouds in the area. There is around a 30% chance of MVFR ceilings
Wednesday morning (15% chance of IFR) but due to disagreements in
models, confidence at this time is low in how far the marine push
will reach inland. Northwest winds 5-10 kt becoming northeast at 5
kt overnight.

HPR

&&

.MARINE...High pressure/upper-level ridging will continue to build
over the Pacific through the week, resulting in northwest flow
translating to north/northwest surface winds. This afternoon`s push
is expected to bring gusty winds to the coastal waters, and then the
Strait of Juan de Fuca (will continue the small craft advisories).
Another push is expected in the strait late Wednesday afternoon into
Thursday, with a much stronger push (potentially resulting in gales)
arriving over the coastal waters/strait Friday into Saturday (as a
result of a trough pushing through). Winds die down for most areas
(except the outer coastal waters) this weekend into early next week.

Seas will hold around 4 to 6 ft through Friday before increasing 8
to 12 ft from Friday into the weekend, reducing to 6 to 8 ft next
week.

HPR

&&

.HYDROLOGY...The daily hydrology discussion has ended until the
start of the next rainy season; it will only be updated as needed.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 11 PM PDT this evening for West
     Entrance U.S. Waters Strait Of Juan De Fuca.

     Small Craft Advisory until 5 AM PDT Wednesday for Central U.S.
     Waters Strait Of Juan De Fuca-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.

     Small Craft Advisory from 5 PM this afternoon to 5 AM PDT
     Wednesday for East Entrance U.S. Waters Strait Of Juan De
     Fuca.

     Small Craft Advisory until 5 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.

&&

$$