Cushman Dam, Washington Weather Forecast Discussion

015
FXUS66 KSEW 022206
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
306 PM PDT Thu Oct 2 2025
.SYNOPSIS...An upper level low just offshore will get pushed
southward tonight into tomorrow, wrapping up precipitation
chances for most of the area tonight. Another upper level wave
will move across the area Friday night into Saturday, bringing
another round of light precipitation chances. Slightly cooler
conditions Saturday and Saturday night. Upper level ridging will
build over the area for the first half of next week, though there
is considerable uncertainty with the potential for additional
systems by mid-week.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...A low pressure system that
has been sitting just offshore of Vancouver Island slowly begin to
weaken and sink southward this evening as it beings to lose upper
level support due to the upper level trough aloft getting
stretched southward down towards California. Showers will
continue, mostly along the western half of the area, through the
rest of the day before tapering off after sunset this evening.
There`s a slim (10-15%) chances of an isolated lightning strike or
two near the coast/over the waters, but we have yet to see any
lightning so far today.
Clearing skies tonight should allow us to dip back into the 40s
to near 50 in the metro area tonight. Areas of fog and low stratus are
possible by Friday morning. A weak cold front will move across
the area from the northwest Friday night into Saturday. Some light
precipitation chances are possible Friday night, but amounts will
be slim to none. What it will bring is slightly cooler
conditions, with highs on Saturday in low 60s with lows in the low
to mid 40s. 30s will be possible in the foothills with low
temperatures below freezing possible for elevations above 5000 ft
in the North Cascades. This will be short lived, however, as an
upper level ridge begins to nose in on Sunday and starting a
warming trend into next week.
.LONG TERM /MONDAY THROUGH THURSDAY/...The aforementioned upper
level ridge will continue to amplify and build over the Pacific
Northwest through the beginning of the week. Temperatures are
expected to warm into the upper 60s to low 70s by Tuesday. Model
solutions diverge quite a bit from Wednesday and beyond. Some
solutions are bringing in an upper level low or a shortwave trough
through the area--which would keep precipitation chances in the
forecast--while others keep the ridge overhead. As such, the full
distribution for highs in Wednesday ranges form the low 60s to
low 70s. The mean solution keeps temperatures in the mid 60s with
chance PoPs from Wednesday morning beyond.
62
&&
.AVIATION...Southwest flow aloft will transition to more northerly
on Friday as ridging offshore nudges into Western Washington. VFR
conditions this afternoon with mid and high clouds as a frontal
system weakens offshore. Scattered showers continue as well,
primarily over the Olympic Peninsula, with more isolated activity in
the interior. Dry conditions will return tonight. Cigs will lower
tonight into Friday morning, with areas of LIFR/IFR cigs, especially
along the coast and into portions of southern and central Puget
Sound. In addition, light winds and residual moisture may promote
fog development, particularly in the aforementioned areas.
Otherwise, cigs will slowly improve to VFR for Friday afternoon.
S/SW surface winds will become light tonight.
KSEA...VFR conditions with mid and high clouds. A few showers may be
around the terminal, mainly through 03z. Some clearing early tonight
before cigs lower Friday morning. There remains uncertainty in
regards to the extent of low stratus or fog in the morning. At this
time, however, IFR cigs are forecast. Current probabilities for
IFR/LIFR cigs are 25% and 20% respectively between 13 and 18z. S/SW
surface winds will continue, becoming light tonight. JD
&&
.MARINE...Southerly winds will continue to dissipate into this
evening as the weather system offshore weakens. A Small Craft
Advisory remains in effect through this evening for the Coastal
Waters primarily due to seas slowly subsiding below 10 feet.
Otherwise, weak onshore flow expected into Saturday. Northerly winds
will then increase over the weekend, with high pressure building
into early next week. Winds expected to be below SCA threshold
Friday into early next week.
Combined seas of 9 to 12 feet will subside below 10 feet tonight.
Seas generally of 4 to 6 feet are expected Friday into the
weekend. JD
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 5 PM PDT this afternoon for Coastal
     Waters From Cape Flattery To James Island 10 To 60 Nm-
     Coastal Waters From Cape Flattery To James Island Out 10 Nm-
     Coastal Waters From James Island To Point Grenville 10 To
     60 Nm-Coastal Waters From James Island To Point Grenville
     Out 10 Nm-Coastal Waters From Point Grenville To Cape
     Shoalwater 10 To 60 Nm-Coastal Waters From Point Grenville
     To Cape Shoalwater Out 10 Nm-Grays Harbor Bar.
Small Craft Advisory until 2 PM PDT this afternoon for East
     Entrance U.S. Waters Strait Of Juan De Fuca-Northern Inland
     Waters Including The San Juan Islands.
&&
$$

NWS SEW Office Area Forecast Discussion