563
FXUS66 KSEW 250305
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
705 PM PST Sun Nov 24 2024

.SYNOPSIS...An upper-low will continue to churn off the PNW coast
for the start of the new week with active weather continuing. Drier
conditions expected towards the Thanksgiving holiday as an upper
level ridge brings calm weather but cooler temperatures.

&&

.UPDATE...Showers are still continuing in the southern-half of the
county warning area this evening (from the Southwest Interior
northward into Puget Sound). Guidance keeps some showers going
overnight into Monday. Still on track to see some drier weather
going into this week - please see discussion below for more
details.

HPR

&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...Activity slowing down
somewhat over W WA this afternoon...but looking into far SW WA and
NW OR, this may be more of an instance of reloading as showers there
look to be on a northeasterly trajectory. Radar trends suggest that
by the time these showers make their way into the CWA, they will
likely be more of a concern for the Cascades and not so much for
remaining areas. That said, there is still some scattered activity
over portions of the Olympic Peninsula as well as along the east
Sound...but these echoes are pretty light with not much in the way
of rainfall expected.

Model solutions remain consistent for the near term with both
deterministic and ensemble members slowly pulling aforementioned low
southward throughout the day today. This will allow the system to
draw moisture up into W WA to continue to fuel the shower risk today
and Monday. Once the low starts to make its way inland, models
remain in agreement that its storm track will take it more into
central or southern OR, thus taking its moisture with it. While this
may still allow for some showers to persist over portions of the
CWA, this will ultimately allow for lowering PoPs and drying
conditions for Tuesday. Upper level ridging will nudge into W WA
Wednesday initiating an overall dry period, however models continue
to agree that this feature will not scour moisture out immediately,
allowing for some low-end PoPs to linger over much of the area.
Terrain coupled with this moisture will lead to better PoPs over the
Cascades.

High temps for the entirety of the short term lingering in the mid
40s to around 50 with overnight lows in the upper 30s to lower 40s.

18

.LONG TERM /THURSDAY THROUGH SUNDAY/...Long term forecast, much
like the short term, remains pretty consistent with upper level
ridging dominating the weather pattern at least into Friday.
Starting to see some deviations in the Friday/Saturday time frame
as deterministic GFS wants to break down the ridge early in favor
of an incoming frontal system. Neither ECMWF nor majority of
ensemble members are indicating such...so while NBM is busy trying
to squeeze PoPs from a stone, the best likelihood still sides
with dry conditions persisting. GFS recalibrates itself with
ridging resuming for the closing frame of the long term with dry
conditions Saturday and Sunday.

Daytime highs slip a little, but not much...ranging in the mid to
upper 40s while overnight lows do end up getting colder in the lower
to mid 30s.

18

&&

.AVIATION...Upper level low slowly drifting south offshore with
moist southwesterly flow aloft over the area. Light easterly
gradients in the lower levels. MVFR ceilings continuing into Monday
afternoon with scattered shower activity. Possible IFR ceilings over
the Kitsap Peninsula with a little upslope flow into the Olympics.

KSEA...MVFR ceilings through Monday afternoon with rain showers.
Easterly winds generally 6 kt or less briefly shifting NE this
evening before turning S/SE by 12z Mon.

Felton

&&

.MARINE...A surface low west of Cape Disappointment will continue to
weaken as it drifts east tonight and Monday. The low will dissipate
off the Oregon coast Monday night. High pressure will build over the
waters Tuesday and remain over the waters through Friday. Winds
remaining below small craft advisory through late week.

Waves generally 6 to 7 feet easing to 4 to 5 feet towards mid-week
and returning to 6 to 7 feet towards next weekend.

15

&&

.HYDROLOGY...The Skokomish River will remain near flood stage
into Monday with light precipitation overnight. The river will
slowly recede beginning Monday night dropping below flood stage
Monday night into Tuesday. The river will remain below flood stage
the remainder of the week.

For the rest of the rivers no flooding is expected with no
hydrologically significant precipitation in the forecast. Felton

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...None.
&&

$$