343
FXUS66 KSEW 221123
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
323 AM PST Fri Nov 22 2024

.SYNOPSIS...An upper-low looks to churn off the PNW coast through
the start of next week with active weather. A strengthening
surface low (not as intense as Tuesday`s) will brush across the
region today with widespread precipitation and gusty winds.
Conditions look to settle towards the middle of next week as
guidance hints at the return higher heights.


&&

.SHORT TERM /TODAY THROUGH SUNDAY/...Good morning, western
Washington. Current temperatures as of 1120 UTC: Hoquiam 46 F,
Tacoma Narrows Airport 46 F, Port Angeles 45 F.

Taking a look at recent satellite/radar trends there`s stuff to
talk about this morning. A sub 990 mb surface low is deepening
over the NE PAC. It`s spreading precipitation ahead of an occluded
front from south to north across the region as it parallels the
PNW coastline. Here locally, we`ll see rain persist through the
early morning hours before breaking into showers by midday. Can`t
rule out a slight chance (15%) of thunderstorms, primarily along
the coast this afternoon. Accompanying rainfall, a tightening
pressure gradient will bring another round of gusty winds as a
Wind Advisory is in effect for the coast, western Whatcom, and
Cascade foothills adjacent to gaps. Gusts upwards of 45 to 55 mph
are in the forecast. HREF guidance is hinting at a 40% chance for
easterly gap wind gusts nearing 60 mph for a few hours this
morning as well. Although not the most likely scenario it is
within the realm of possibility. Wrap-around showers are to remain
in the forecast tonight as the low center gradually ushers away
towards Vancouver Island. Overnight lows are to bottom into the
40s. Additionally, a high surf advisory will be in effect Friday
for waves of 20 to 24 feet.

Showers are to remain in the weekend forecast (with snow showers
for the mountains) due in part to the upper-low churning
offshore. Again, can`t rule out a rumble of thunder or two
occuring over the coastal waters/WA coastline. Temperatures are to
remain fairly seasonal with highs near 50 F and overnight lows in
the 40s.


.LONG TERM /MONDAY THROUGH THURSDAY/...Models continue to hint at
the upper level low moving inland by Tuesday. With the low
expected to depart off and eastward, it appears the wet weather
will be replaced with drier weather come midweek as ridging builds
offshore allowing dry northerly flow into the PNW, just in time
for the Thanksgiving holiday.


&&

.AVIATION...Another deep, stacked low pressure system will swing
off the coast today with strong winds along the coast. The flow
aloft is southerly. Winds will be easterly in the interior early
this morning then switching to south or southeast by 16-19z as an
occluded front moves inland. Winds will ease late tonight. Rain
with this system will bring brief MVFR cigs this morning, then VFR
this afternoon and evening with showers. The air mass is unstable
along the coast for a chance of thunderstorms. 33

KSEA...Brief MVFR conditions with rain early this morning. Winds
easterly, switching to S and increasing with gusts to 20 kt around
18z. VFR with showers through the afternoon and evening. 33

&&

.MARINE...A deep surface low will track north off the coast today
with storm force winds over the coastal waters and seas building
over 20 ft. Easterly gales will also develop through the Strait
of Juan de Fuca. Winds will ease and seas will subside this
weekend as the low weakens over the offshore waters. 33


&&

.HYDROLOGY...The Skokomish River will stay in action today,
before climbing up into minor flood stage tonight.

For the remainder of the rivers no flooding is expected at this
time. Lower snow levels into the weekend in the Cascades will
limit runoff and reduce any flooding chances for rivers flowing
off the Cascades. Precipitation for the remainder of the period
will come in bursts. This combined with snow levels remaining
relatively low will keep rivers in their banks.


&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Wind Advisory until 10 AM PST this morning for Bellevue and
     Vicinity-East Puget Sound Lowlands-Western Whatcom County.

     Flood Watch through late tonight for Hood Canal Area-Lower
     Chehalis Valley Area-Olympics.

     High Surf Advisory from 9 AM this morning to 10 PM PST this
     evening for Central Coast-North Coast.

     Wind Advisory from 10 AM this morning to 4 AM PST Saturday for
     Central Coast-North Coast.

PZ...Small Craft Advisory until 4 AM PST Saturday for Admiralty Inlet-
     Grays Harbor Bar-Puget Sound and Hood Canal.

     Gale Warning until 4 AM PST Saturday for Central U.S. Waters
     Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of
     Juan De Fuca-Northern Inland Waters Including The San Juan
     Islands-West Entrance U.S. Waters Strait Of Juan De Fuca.

     Storm Warning until 4 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.

&&

$$