Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
744
FXUS66 KSEW 301618
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
918 AM PDT Sun Aug 30 2026
.UPDATE...
No changes made in this morning`s update. The previous
discussion remains below along with an updated aviation section:
&&
.SYNOPSIS...
Upper level ridge over the area today with a weak system moving
into Southern British Columbia. Ridge builds tonight before
moving east Monday. Weak warm front moving into the area Tuesday
night followed by a strong for September cold front Wednesday
into Wednesday night. Upper level low associated with the front
remaining in the vicinity Thursday and Friday. The low will
move out of the area Saturday.
&&
.SHORT TERM /TODAY THROUGH TUESDAY/...
Satellite imagery shows mostly cloudy skies over Western
Washington early this morning with some breaks in the cloud
cover over the South Puget Sound and along the Strait of Juan de
Fuca. Temperatures at 3 am/10z were in the mid to upper 40s
where there are breaks in the clouds and in the 50s elsewhere.
Flat upper ridge over the area today. Weak system moving into
Southern British Columbia will give locations near the Canadian
border a slight chance of showers this morning. Between the
cloud cover this morning and increasing middle and high level
clouds from the system moving by to the north mostly cloudy day
in store. Highs in the 60s and lower 70s.
Upper level ridge building tonight in response to a digging
trough offshore. Cloud cover decreasing overnight. Longer nights
plus some low level moisture from Saturday leading to patchy to
areas of fog in the fog prone locations after midnight. Cool
morning with lows in the mid 40s to mid 50s.
Upper level ridge moving east Monday. Marine layer remaining
west of Puget Sound in the morning retreating to the coastline
in the afternoon. Under mostly sunny skies highs getting back to
near normal, in the mid 60s to mid 70s.
Western Washington on the backside of the upper level ridge
Monday night. Increasing middle and high clouds Tuesday as the
warm front associated with a deep upper level low moving out of
the Gulf of Alaska. Could see some sprinkles west of the Sound
Tuesday afternoon. Highs in the mid 60s to lower 70s.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Weak warm front Tuesday night for a chance of rain over the
area. Model solutions becoming inconsistent again with the
current run. The models are having a hard time with the track
of the upper level low. Current run has a more north south track
off the coast which will slow down the arrival of the front
into Western Washington with the cold frontal passage Wednesday
night. A little slower than previous runs. Windy conditions
developing along the coast and over the Northwest Interior.
While the winds speeds might not get up to advisory category
with plenty of foliage plus trees not in great shape after a dry
summer there could be more impacts with this system versus a
similar one a month or so later.
Model inconsistencies continue Thursday and Friday with the GFS
taking the low far enough to the south to keep more
precipitation out of the forecast. The ECMWF parks the low off
the coast with a couple of impulses spinning out of the low
moving through the area. Ensemble solutions favor the ECMWF
solution Thursday and lean towards the GFS Friday. Confidence
low at this point with a lack of consensus in multiple model
runs. Will go chance to likely pops Thursday with chance to
slight chance pops Friday.
Differences continue Saturday with the ECMWF kicking the low out
to the northeast while the GFS sinks the low south. Saturday has
the best chance of being a dry day in the extended. For now will
keep some slight chance pops in the forecast.
Cool Wednesday and Thursday with highs in the lower to mid 60s.
A little warmer Friday and Saturday with highs in the mid 60s to
lower 70s. Lows in the upper 40s and 50s. Felton
&&
.AVIATION...
West to northwest winds continue aloft as an upper level trough
continues to depart east and brief ridging moves in. Ceilings are a
mix of MVFR and VFR with scattered lower clouds and high clouds
draped across the northwestern portions of the region.
Expect low clouds to clear out between 18-21Z this morning becoming
mostly clear, but mid-level clouds will remain in place over the
northwest, including BLI. VFR conditions will then continue through
this evening. Guidance is hinting at the potential for some
localized fog development early Monday morning, but it may depend on
the amount of clearing as high clouds will filter overhead. The
locations most likely to see fog are HQM, OLM, and PAE. Winds
generally light southwesterly to more north/northwesterly by this
evening and continue overnight and into Monday.
KSEA...MVFR cigs continue early this morning, but are expected to
lift up to VFR by around 18-19Z this morning and will continue to
remain VFR overnight. High clouds will continue to stream overhead
tonight. Fog development is uncertain (around 10% chc), but is more
likely to remain outside of the terminal. SW winds around 5 kt will
transition to N this evening and persist overnight into Monday. 62
&&
.MARINE...
A trough will move out of the region and into the Rockies today,
with additional systems bypassing the waters to the north Monday and
Tuesday. Winds and waves across the waters will likely remain
benign, although the light winds and combination of low level
moisture from recent rains may lead to pockets of fog forming Monday
morning across the coastal waters and west Strait of Juan de Fuca.
Models remain persistent that a stronger low pressure system will
move in Tuesday night, lasting into Thursday, bringing fall-like
conditions across the waters. Probabilities for gusts up to gale
force for portions of the southern coastal waters and east Strait of
Juan de Fuca remain at 60-70%. Once the system moves out, winds will
become light out of the north and west going into next weekend.
Seas at 3-6 ft through midweek, then increasing to 8-11 ft around
Wednesday through Thursday, before dropping back to 4-6 ft next
weekend.
HPR
&&
.FIRE WEATHER...
Cooler weather with good relative humidity recoveries overnight
through Tuesday easing fire weather concerns over the area.
Strong for the first week of September system arriving
Wednesday will bring abundant rainfall to the coast and
Olympics. Two to three inches of rain are forecast in the
Olympics, one to one and a half inches for the coast. For the
interior and the Cascades a half inch to an inch is in the
forecast through Thursday morning. This is good news for the
fires still burning from the Cascade crest westward. Weather
remaining cool through the end of the week with chances of
additional precipitation keeping fire weather concerns in check.
Felton
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...None.
&&
$$
NWS SEW Office Area Forecast Discussion