Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
292
FXUS66 KSEW 012143
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
243 PM PDT Thu Oct 1 2026
.SYNOPSIS...Zonal flow aloft into Friday with precipitation
chances along the northern portions of Western Washington. Warm,
dry conditions over the weekend as an upper ridge builds over
the Pacific Northwest. Onshore flow returns early next week with
the return of near normal temperatures but continued dry
conditions.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...West flow aloft
continues into Friday with a building upper level ridge across
the majority of the Western US. A weakening weather system will
move across the northern periphery of the ridge into BC into
Friday, resulting in continued mid and high clouds at times.
Although the majority of precipitation will remain in BC, light
rain at times may occur along the northern Olympic Peninsula and
Whatcom County into midday Friday. Otherwise, temperatures
remain near to slightly above normal through Friday.
The upper ridge builds further across Western Washington Friday
night into the weekend resulting in dry conditions and warming
temperatures. Stratus and areas of fog are expected Saturday
morning around Puget Sound with relatively light north winds.
Clouds will clear for sunny conditions in the afternoon.
Temperatures Saturday will peak in the mid 60s to mid 70s, and
even in the low 80s in the Cascade Valleys under light offshore
flow.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...The upper ridge will
remain in place over the majority of the Western US on Sunday,
resulting in temperatures being a few degrees warmer by Sunday
afternoon, and continued dry conditions. Ensembles are
consistent in the ridge beginning to flatten over Western
Washington on Monday, with onshore returning, and a slight
cooling trend in temperatures along with increasing morning
stratus. Dry conditions are expected into midweek though with
continued ridging influence. JD
&&
.AVIATION...Westerly flow aloft continues through Friday with an
upper ridge across the Southwest US and a weakening frontal
system moving into British Columbia. Widespread VFR mid and high
clouds this afternoon with light rain along the BC border. VFR
cigs into this evening with IFR/LIFR stratus developing late
tonight along the coast. Stratus will slowly slide into southern
Puget Sound early Friday morning. At this time, MVFR/IFR stratus
is expected to mainly remain from the Kitsap Peninsula
westwards, with lower probabilities for stratus east of Puget
Sound. Otherwise, clouds will lower towards MVFR Friday AM at
KBLI near the front. Mainly VFR Friday afternoon, with continued
stratus along the Olympic Peninsula. Light winds increasing from
the S/SW Friday afternoon.
KSEA...VFR high clouds into tonight. Stratus will move inland
towards southern Puget Sound early Friday AM. At this time,
MVFR/IFR stratus is expected to remain west of the terminal.
However, there is a 20% probability of IFR cigs between 13 to
18z Friday. Otherwise, VFR mid and high clouds on Friday. Light
NW winds, less than 5 kts, into tonight, before winds transition
S/SW between 07-09z and increase Friday. JD
&&
.MARINE...High pressure continues across the waters this week.
A weak front will move north of the area into Friday, but little
in the way of wind impacts are expected. A thermal trough builds
Saturday bringing northerly to offshore winds Saturday and
Sunday. Onshore flow returns late Monday with a westerly push
through the Strait of Juan de Fuca Monday evening. Generally
light flow then returns into midweek. Seas are expected to
remain between 4 to 6 feet through early next week. JD
&&
.FIRE WEATHER...Fire weather concerns remain minimal through
the next few days. Developing high pressure aloft this weekend
with a thermal trough building up the coastline will bring warm
temperatures and light offshore flow. This could result in
locations in the Cascades and adjacent valleys seeing minimum RH
values approach 30% on Sunday. This will be short lived, with
onshore flow returning early next week to boost humidity values
and cooler temperatures.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...None.
&&
$$
NWS SEW Office Area Forecast Discussion