Clearview, Washington Weather Forecast Discussion

717
FXUS66 KSEW 051633
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
933 AM PDT Fri Sep 5 2025
.SYNOPSIS...Upper level ridge over the area today will slowly move
east tonight into the weekend. Upper level low west of Haida
Gwaii this morning will move south and be off the Oregon coast by
Sunday. Upper level disturbances spinning out of the low moving
over Western Washington beginning tonight and continuing through
the weekend. Low moving east Monday stalling and weakening into a
trough over the Pacific Northwest Monday night through Wednesday.
&&
.SHORT TERM /TODAY THROUGH SUNDAY/...The latest forecast remains
on track with no updates this morning. High amplitude upper level
ridge over Western Washington today with an upper level trough
digging south well offshore. HRRR smoke models have smoke aloft
over the area all day. Stratus this morning will continue to
slowly move eastward and could get east of Puget Sound for a
couple of hours after sunrise before retreating back to the
coastline by late morning/early afternoon. Weak upper level system
spinning out of the offshore low remaining south of the area but
close enough for a chance of showers around Mount Rainier late in
the day. High temperature forecast will be a little tricky with
the upper level smoke. Have knocked 3 to 5 degrees off the NBM
highs due to the smoke. This puts highs in the 70s and lower 80s
inland and in the mid 60s along the coast.
Upper level ridge axis east of the area tonight. Weak upper level
shortwave moving through overnight into early Saturday morning
with a chance for showers spreading north. Upper level smoke
remaining but will be obscured by the increasing cloud cover. Lows
in the mid 50s to lower 60s.
Upper level ridge continuing to drift east Saturday while the
upper level low offshore digs south and also moves a little east.
A stronger shortwave spinning out of the low reaching Western
Washington late in the afternoon. Air mass somewhat unstable with
lifted indexes well below 0, lapse rates in the plus 7 to 8C range
along with elevated CAPE values. On the flip side convective
temperatures are well above predicted high temperatures and model
soundings have a cap between 850-700 mb. For now will stay with
the slight chance of late day thunderstorms in the lowlands with a
better chance over the mountains in addition to the chance of
showers. With the cloud cover and increase in onshore flow highs
cooler than today, mid 60s to mid 70s.
Chance of showers with a slight chance of thunderstorms
continuing Saturday evening until the shortwave exits to the north
after midnight. Lows in the mid 50s to lower 60s.
Upper level low offshore drifting towards the coast Sunday with
the flow aloft becoming difluent over the area in the afternoon.
This will keep a chance of showers in the forecast. With plenty of
cloud cover highs will remain mostly in the 60s.
.LONG TERM /MONDAY THROUGH THURSDAY/...Extended models in pretty
good agreement with the upper level low weakening into a trough
and stalling over the Pacific Northwest later Monday into
Wednesday keeping the mostly cloudy chance of showers or showers
likely forecast going into the middle of next week. Temperatures
will remain below normal with highs in the 60s and lower 70s.
While the operational runs indicate some ridge building Thursday
the ensembles are not as emphatic with the ridge. Not many wet
solutions in the ensembles but enough to keep a chance of showers
in the forecast. Highs remaining just a little below normal, mid
60s to mid 70s.
&&
.AVIATION...An upper ridge east of the Cascades and an
upper trough offshore will continue to produce south to southeast
flow aloft over Western Washington. Weak low level onshore flow
continues. Shallow marine stratus producing LIFR/IFR ceilings will
gradually burn back to the immediate coast by 18Z-20z. An upper
level disturbance will produce elevated instability for isolated
showers and thunderstorms across southern portions of the area late
today into Saturday morning. Another round of low stratus and patchy
fog is expected Saturday morning.
KSEA...A shallow marine layer producing LIFR ceilings is expected to
remain in the vicinity of the terminal through 17Z before scattering
out near or after 18Z. Hazy conditions persist through the day with
increasing high and mid level clouds later in the day. Convective
activity is expected to remain south of the terminal through 12Z
tonight. Another period of LIFR/IFR stratus is likely 12Z-18Z
Saturday morning. Surface winds light becoming W/NW 4 to 7 knots
this afternoon then shifting S/SW 6 knots or less tonight.
27
&&
.MARINE...A weak surface ridge will remain over the coastal and
offshore waters today with lower pressure over the interior
producing light onshore flow. A weak trough will gradually move into
the coastal waters over the weekend into early next week, but will
produce little in the way of impacts. Diurnal westerlies through the
strait may reach SCA criteria later over the weekend but confidence
is not high at this time.
McMillian
&&
.FIRE WEATHER...Increasing onshore flow early this morning will
increase the RH values across the area including the foothills
today. Late afternoon RH values were 5 to 10 percent higher late
Thursday afternoon versus Wednesday afternoon and this trend will
continue today. There is a chance of showers over the weekend with
a slight chance ( 20% or less ) of widespread thunderstorms in
the late afternoon and evening Saturday. There is a slight chance
for thunderstorms possibly as early as late this afternoon for the
very southern end of the west slopes of the Cascades. Confidence
remains low with exact coverage and intensity of the convective
activity. Cool and showery weather Sunday into the middle of next
week will keep the fire danger suppressed.
Felton
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...None.
&&
$$

NWS SEW Office Area Forecast Discussion