Lake Crescent, Washington Weather Forecast Discussion

705
FXUS66 KSEW 071043
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
343 AM PDT Sun Sep 7 2025
.SYNOPSIS...An upper level low will remain offshore through
Monday, before pushing inland Monday night into Tuesday. This
system will maintain cooler conditions and chances for showers
and thunderstorms at times across western Washington through the
first part of the week. A brief period of drier conditions will be
possible the latter half of the week, before another system brings
increasing rain chances to the region again by the weekend.
&&
.SHORT TERM /TODAY THROUGH TUESDAY/...The majority of thunderstorm
activity has waned over the region early this morning, with the
latest radar showing showers and isolated thunderstorms- mainly
along the Cascade crest- continuing to progress northward across
western Washington at this time. While thunderstorm activity will
remain possible through the early morning hours, expect coverage
to mostly be limited to the Cascades.
Overall, expect cool and unsettled conditions to continue across
western Washington throughout the short term as an upper level low
offshore deepens today and moves inland over the region Monday
night into Tuesday. The greatest chance for thunderstorm development
across the region today are across the Olympics and Cascades,
where guidance generally hints at a 10-20 percent chance of
convection developing by this afternoon and evening. The exception
remains the North Cascades, where there is a 25-30 percent chance
of development. Chances for convection look to become more
confined to the Cascades by Monday, however could become more
widespread again by Tuesday as as the upper level low pushes
inland south of the area. Overall, expect conditions to remain
cool across the region, with afternoon high temperatures in the
60s along the coast and low to mid 70s across the interior today
and Monday. Tuesday looks to be the coolest day within the short
term with afternoon highs only expected to get into the upper 60s
for most spots across the interior.
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...The upper level low
looks to linger across the region through Friday, before ejecting
northeastward out of the area over the weekend. Model guidance
does continue to show upper level ridging starting to build in
along the coast Thursday and Friday. Should this come to fruition,
this would bring a brief drying trend to portions of the lowlands,
though some wrap around moisture from the upper low may bring
some showers and thunderstorms to portions of the Cascades during
this time. Temperatures will climb a few degrees across the interior,
with highs expected to top out in the mid 70s. Unsettled weather
looks to return for the weekend, however, as the next system moves
in from the Pacific.
&&
.AVIATION...The interplay between the upper level ridge currently
centered over W MT and an upper level low over the Pacific will
allow for southerly flow to transition to southwesterly flow aloft
by this afternoon, returning to southerly early Monday morning as
the upper low moves eastward into the area. Surface winds generally
southerly with some variances to the SE or SW due to location and
nearby terrain influences. HQM and OLM are exceptions as they have
gone light and variable while CLM remains more westerly due to
diurnal push down the Strait. Speeds generally 5-10 kts, although
BLI seeing 8-12 kts with occasional gusts. Overall, little in the
way of changes to neither speeds nor direction is expected
throughout the TAF period.
Cigs generally MVFR or lower as showers and thunderstorms continue
over portions of the area...although there are some isolated areas
of VFR conditions, including SEA, PAE, PWT and OLM. It is worth
noting that showers seem to be moving toward each of those
terminals, so cigs will likely lower to at least MVFR by 10Z this
early morning. Widespread MVFR or lower cigs expected by 12Z due to
plenty of low-level moisture to work with from aforementioned
showers. Expectation is that terminals will be slower to recover
today...with cigs likely not returning to VFR until after 20Z. As
the risk for showers and isolated thunderstorms will persist into at
least late this morning, VCSH will continue to represent these
chances. PoPs drop below 30 pct after 20Z area-wide and as such,
confidence is not there for further inclusion.
KSEA...Above discussion applies. VFR conditions in place with some
showers having already passed near the terminal. Radar continues to
show echoes nearby, with additional showers possible through 11Z
this morning. MVFR conditions could emerge with showers, but even if
they should miss the terminal, cigs should sink into this category
between 10-12Z this morning. Recovery timing is above. Winds will
trend more southwesterly, with no significant change in direction
nor speed, again as stated above. Latest trends showing that thunder
is not expected to be a threat for the remainder of the morning and
any thunder in the afternoon will likely be relegated to the higher
terrain of the Cascades.
18
&&
.MARINE...A weak surface ridge over the coastal and offshore waters
will be replaced by a weak low today. This general pattern will
persist through the first half of this week before a stronger
surface ridge rebuilds offshore around mid-week.
Seas 2 to 4 ft through at least Tuesday night, increasing to 4 to 6
ft by Wednesday.
18/27
&&
.FIRE WEATHER...Thunderstorm chances will linger across the
mountains today and gradually become more confined to the Cascades
on Monday as additional disturbances push up and across the
region from the low offshore. The main hazards with any
thunderstorm development remain gusty erratic winds, brief heavy
downpours, and frequent lightning. Tuesday may bring another round
of more widespread showers and Cascade thunderstorm chances as
the low moves onshore over the region. Outside of thunderstorm
activity, the continued trend of cooler and cloudier conditions
and increased moisture across the region should act to alleviate
fire weather impacts as the week progresses.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Red Flag Warning until 5 AM PDT early this morning for West
     Slopes of the Central Cascades Generally above 1500 Feet.
PZ...None.
&&
$$

NWS SEW Office Area Forecast Discussion