903
FXUS66 KSEW 132303
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
303 PM PST Mon Jan 13 2025

.SYNOPSIS...High pressure over Western Washington will bring
multiple rounds of morning fog and low stratus over the next few
days. A weak system midweek will bring precipitation chances on
Thursday. Cooler and drier conditions return for the weekend and
early next week.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY/...Some improvement was seen
across some locations in Western Washington today, as the fog and
low stratus managed to erode, giving way to some partly cloudy
skies. However, some locations struggled throughout the day. A
similar pattern can be expected over the next few days as an upper
level ridge situated over the region will bring multiple rounds
of morning fog and low stratus.

Late Wednesday night a shortwave trough will descend towards
British Columbia, bringing light precipitation (lowland rain and
mountain snow) chances on Thursday. Based on model guidance, this
system will be relatively weak with no significant impacts
expected. Most of the precipitation will be centered around the
Northern and Central Cascades. The lowlands may see a stray shower
or two with this system. Increased cloud cover and winds will
likely provide some relief from the morning fog on Thursday
morning.

The deterministic NBM is showing a small chance at some light
rain/snow mix along parts of the interior lowlands late Thursday
night into Friday morning. Confidence is high that temperatures
will be near freezing; however confidence is very low on any
precipitation accumulating due to low PoPs at this time.

.LONG TERM /FRIDAY THROUGH MONDAY/...A cooling trend is set to
ensue starting on Friday and will get colder throughout the
weekend. High temperatures on Friday will peak in the low 40s. By
the weekend, temperatures will likely struggle to go above 40
degrees. Low temperatures on Friday will be in the low 30s across
the lowlands. By the weekend, low temperatures are expected to
decrease into the mid 20s. It is possible that a Cold Weather
Advisory may need to be issued in the next coming days for some
portions of Western Washington, as some models are already
hinting at apparent temperatures being near/within threshold
criteria.

An upper level ridge will rebuild off the Pacific during the
weekend likely keeping Western Washington dry for the remainder
of the weekend and early next week. Temperatures and precipitation
are looking to trend below normal, according to the Climate
Prediction Center`s 6-10 Day Outlook.

MGF

&&

.AVIATION...Strong high pressure remains over the region for dry
and stable weather. Light winds and poor mixing will trap low
level moisture near the surface for IFR to LIFR conditions. Slow
lift of the stratus on Tuesday but ceilings likely remaining in
MVFR range. 33

KSEA...IFR to LIFR conditions through 20z Tuesday with N/NE winds 5
kt or less. 33

&&

.MARINE...High pressure will remain over the waters through
the majority of the week. Expect 10 foot seas over the outer
coastal waters through Wednesday. A weak front will move across
the waters Thursday into Friday for increasing north winds. 33

&&

.HYDROLOGY...River flooding is not expected through the next seven
days.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 6 PM PST Tuesday 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.

&&

$$