Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
191
FXUS66 KSEW 281024
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
324 AM PDT Fri Aug 28 2026
.SYNOPSIS...
Upper level trough remaining over Western Washington through
Saturday morning. Small upper level low developing in the
trough moving over the area tonight into Saturday. Trough and
low move east Saturday afternoon and evening. Weak upper level
ridge moving through Sunday. Upper level trough developing
Monday remaining offshore. Warm front brushing Western
Washington Tuesday with the trailing cold front arriving
Wednesday. Front possibly stalling over the area into Thursday.
&&
.SHORT TERM /TODAY THROUGH SUNDAY/...
Satellite imagery shows a combination stratus and high clouds over
Western Washington early this morning. No precipitation echoes
on the doppler radar. Temperatures at 3 am/10z were in the 50s
and lower 60s.
Weak upper level trough over the area combined with light low
level onshore flow making for a cloudy morning. Chance of
showers this afternoon over the northern portion of the area
while the clouds decrease over the southern portion. Highs in
the 60s and lower 70s.
Upper level low moving down the British Columbia coast tonight
ending up over Northwest Washington by 12z Saturday. Shower
activity increasing from about Seattle northward into early
Saturday morning. Mostly cloudy skies over the remainder of the
area. Lows in the 50s.
Upper level low hanging out over the Northwest Interior Saturday
morning before moving east of the Cascades Saturday afternoon.
Showers likely north of Seattle in the morning. A little daytime
heating along with the small pool of cooler air associated with
the upper level producing a slight chance of thunderstorms in
the afternoon over the Cascades and possibly as far west as
Puget Sound with a convergence zone forming in the afternoon. Highs
in the 60s and lower 70s.
Convergence zone dissipating Saturday evening. Shower activity
over the Cascades drying up quickly Saturday night as the upper
level trough moves east and drier northwesterly flow aloft
kicks in. Low level onshore weakening overnight. With the nights
getting longer these days could see some fog forming in the
usual places, Southwest Interior/Cascade river valleys, by
Sunday morning. Chilly morning with lows in the mid 40s to mid
50s.
Temporary upper level ridge moving through Sunday. Light low
level flow in the morning giving the area plenty of morning
cloud cover. Weakening front moving down the British Columbia
coastline spreading high clouds over the area in the afternoon.
Highs once again only in the 60s and lower 70s.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Extended models in pretty good agreement this morning. Front
moving down the British Columbia coast never reaches Western
Washington as an upper level trough digs offshore Sunday night
into Monday. Strong upper level low moving out of the Gulf of
Alaska Monday night will be off the Central British Columbia
coast by Tuesday afternoon. Warm front associated with the low
brushing western Washington Tuesday for a chance of showers.
Highs in the 60s and lower 70s both days.
Models still showing a well organized cold front reaching
Western Washington Wednesday. The new wrinkle in the solution is
the associated upper level low now predicted to have a more
north south track offshore on the ECMWF. This brings up the
possibility of the front stalling over the area Wednesday night
into Thursday. The GFS track is closer to the coast pushing the
front into Eastern Washington leaving Western Washington in a
cool and unstable air mass Thursday. Either way Wednesday and
Thursday look wet and cool. Snow levels as low as 7000 feet by
Thursday. Highs only in the 60s. There is a chance these days
could be the coolest since late June/early July. Felton
&&
.AVIATION...
Westerly to southwesterly flow aloft as upper level troughing
remains over western Washington. VFR at terminals early this
morning will be brief as incoming stratus will bring a mix of
MVFR/IFR ceilings across most terminals. Could see localized
LIFR along coastal terminals, and in areas of the Kitsap
Peninsula. Ceilings will slowly improve by 19z-21z, with a
return of VFR with mid level clouds. S/SW winds will continue
generally 3 to 6 knots. Some terminal sites north of King County
could see winds turn northerly in the afternoon and evening,
but generally still remain light.
KSEA...VFR ceilings early this morning. Ceilings will gradually
lower later this morning as MVFR stratus moves over the
terminal, generally around 10z-13z. Latest guidance shows a
20-25% chance of IFR ceilings over the terminal as well, around
13z-16z. Otherwise, MVFR will continue throughout early
afternoon before rebounding to VFR around 19z-21z. S/SW winds
this morning may take a more N/NW later this evening but
remaining light, after 00z-02z. A weak disturbance looks to
trigger a Convergence Zone later this evening, and may
lower conditions near KPAE at times. At this time, it should
stay generally north of Everett.
Mazurkiewicz
&&
.MARINE...
A weak system will cross over the area waters today for the
continuation of onshore flow. Marine stratus this morning could
reduce visibilities, especially along the coast. Increased
southwesterlies can be expected this afternoon, along with small
craft westerlies through the Central Strait of Juan De Fuca.
Additional weak systems through the weekend will keep onshore
flow across much of the area waters, along with another push
down the Strait of Juan De Fuca on Saturday. Marine winds will
become more benign late into the weekend.
Coastal seas will remain generally around 4 to 6 feet through
the first half of next week.
Mazurkiewicz
&&
.FIRE WEATHER...
Onshore flow, cooler temperatures, and increasing RHs will persist
through next week. There still remains an isolated threat for
thunderstorms Saturday afternoon mainly over the Northern and
Central Cascades. If a thunderstorm develops, wetting rains are
unlikely and lightning may pose a hazard that could lead to new
fire starts. Erratic and gusty outflow winds over existing
fires could also be problematic. Weather system next Wednesday
has a good chance of producing wetting rains along the coast and
over the mountains. Felton
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory from 2 PM this afternoon to 11 PM PDT
this evening for Central U.S. Waters Strait Of Juan De
Fuca.
&&
$$
NWS SEW Office Area Forecast Discussion