Sixteen Lake Washington Weather Forecast Discussion

976
FXUS66 KSEW 091003
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
303 AM PDT Thu Oct 9 2025
.SYNOPSIS...An upper low remains in place off the Pacific coast
for the next few days, allowing for periodic rounds of
precipitation and cool conditions. As a disturbance crosses the
region into the weekend, expect steadier precipitation chances
and even cooler temperatures, with snow levels lowering in the
mountains.
&&
.SHORT TERM /TODAY THROUGH SATURDAY/...The overall pattern will
remain consistent with an upper low remaining centered offshore
for the next few days. This will spread in rounds of precipitation
at times in the southeasterly flow aloft. This will maintain
rather solid cloud cover over the region and occasional
showers. Instability is somewhat marginal, so an isolated
thunderstorm or two cannot be ruled out but the chances will be
best offshore closer to the center of the low where lapse rates
will be steeper. Otherwise, expect mix of showers and drier
weather in between these disturbances rotating through the upper
low. Even some breaks in the clouds can be expected at times in
the afternoon. Temperatures will within a few degrees of normal
through the next few days with high temperatures around 60.
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...The next
disturbance deepens and moves into the region late in the
weekend as it pushes south. This will bring another round of
widespread precipitation to the region as well as usher cooler
air across Western Washington. This looks to bring temperatures
topping out only in the upper 50s for the start of next week.
More significantly, expect the snow level to fall to around
4000-5000 ft Sunday, opening the door for snow in the higher
mountain elevations. Current chances are still around 50% for
snowfall of a few inches at Stevens Pass. While accumulation at
the surface may be limited, this has the potential to bring
several inches of snow to places like Rainy Pass and Paradise
at Mount Rainier. As a result, those that plan to head to the
higher mountain elevations this weekend should be prepared to
encounter snow and cold conditions and closely monitor the
weather forecast in the next few days.
Looking ahead into next week, ensemble guidance continues to
favor the upper low tracking south into California. This begins
to push the precipitation chances away from the region for a
drier trend. As this occurs, however, we may begin to transition
out of the damp, cloudy pattern and will need to monitor the
potential for frost in the mornings as low temperatures trend
closer to the 30s for the sheltered interior locations away from
the water.
&&
.AVIATION...Southerly flow aloft with an upper level low offshore.
VFR conditions prevail across western Washington this morning, with
a band of moisture, mid level clouds, and showers from the metro
area east to the Cascades. This band will move westward throughout
the day. With mid level clouds in place, widespread fog will not be
a concern this morning. Ceilings may slowly lower and a brief period
of MVFR cigs may be possible this morning through around 17-19Z, but
as the moisture bands moves northwest, expect ceilings to raise for
the rest of today into tonight. More widespread lower ceilings to
MVFR will be possible going into early Friday morning. Light
north/northeasterly winds early this morning will increase to around
4 to 8 kt today, but remain light and variable tonight into Friday
morning.
KSEA...VFR conditions through most of the TAF period. Mid level
clouds with showers early this morning with a band of moisture over
the terminal. This band will slowly move northwest this morning.
Showers may allow ceilings to lower this morning, with a brief
period of SCT/BKN MVFR cigs possible, but overall low confidence.
Mid level clouds will remain in place through the rest of today into
tonight. Additional moisture and showers will move in early Friday
with better chances for MVFR cigs after 12Z Fri. Light N/NE winds
will remain N, 4-6 kt today. Winds become light early tonight, with
winds switching to southerly Friday morning.
62
&&
.MARINE...A low pressure system will continue to remain offshore
of Oregon today through Friday. As the system continues to develop
today, winds will become elevated across the outer coastal waters
where winds look to just reach SCA criteria, with gusts up to 25 kt
expected through this afternoon. Winds will ease as the system moves
farther offshore and more to the south as well. The system will move
inland Friday into Saturday. Winds will increase on Saturday as
strengthening high pressure across the NE Pacific pushes in quickly
behind the low. Winds look to reach high-end SCA criteria across the
coastal waters with 40-70% chances for gale force gusts through
Sunday morning. Winds also look to increase through the Strait of
Juan de Fuca as well, but not quite as strong as over the coastal
waters. Another low pressure system looks to develop over the
Washington coast Sunday night into Monday and move southward along
the coast. This will allow winds to turn offshore, with winds
requiring additional headlines possible through the Strait, with
slightly increased probabilities (40-70%) for gale force gusts on
Monday in the central Strait.
Seas 7 to 8 ft this morning will subside to 4 to 6 ft tonight
through Friday. Seas build Saturday to 12 to 16 ft over the weekend.
Seas then look to ease Sunday, becoming 6 to 8 ft for the first part
of next week.
62
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...None.
&&
$$

NWS SEW Office Area Forecast Discussion