Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
502
FXUS66 KSEW 120334
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
834 PM PDT Mon May 11 2026
.SYNOPSIS...
A ridge of high pressure will produce a warming trend through
Tuesday. A transition to onshore flow and cooler temperatures
will take place on Wednesday along with a chance of some
precipitation. Cooler and unsettled conditions are expected into
the weekend as a trough of low pressure over the Northeast
Pacific sends a series of weak frontal systems across the area.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
High pressure over the region will lead to dry conditions and
warmer temperatures moving into Tuesday. Most areas will see
high temperatures in the 70s to lower 80s on Tuesday (Minor
HeatRisk), with pockets of mid/upper 80s in the Cascade valleys.
The flow will be turn onshore during the afternoon and the
warm-up will be brief along the coast.
The ridge kicks east and inland Tuesday night while a trough
moves in from the west. The air mass will be slightly unstable
with moist, diffluent flow, and we may see some showers and
thunderstorms develop over Oregon and drift north during the
overnight hours, mainly over the southern Cascades. Otherwise,
with the return of onshore flow, Wednesday is looking cooler and
in the 60s. And with the trough, we are seeing a chance of
showers and wetting rain in the mountains with a few hundredths
falling in the interior. Showers with a convergence zone may
linger into Wednesday night. 33
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
Western WA is under onshore flow on Thursday, leading to cool
and cloudy conditions with a chance of showers. Convergence zone
showers are expected near the King/Snohomish line. We`ll see an
uptick in shower activity on Friday as a larger trough drops
down from B.C. Isolated thunderstorms are possible as the air
mass will be slightly unstable (primarily during the afternoon
and evening hours). This trough keeps us cool and showery on
Saturday with high temperatures only in the 50s. Weak high
pressure moves in early next week for drier weather and
temperatures closer to average. 33
&&
.AVIATION...
Westerly flow aloft will become southwesterly as
the upper level ridge shifts eastward. Mostly clear skies with
a few high clouds will persist through Tuesday, the only
exception remains the chance of low cigs/vis Tuesday morning
along the coast. N/NW winds 8-12 kt will ease to 5 kt tonight
and become NE. Winds will then switch to the southwest and
increase to 8-12 kt on Tuesday afternoon. There is a 15-20
chance of scattered thunderstorms Tuesday evening, mainly along
the Pierce and Lewis County Cascades.
KSEA...VFR conditions with mostly clear skies, just a few high
clouds moving overhead. NW winds persisting at 8-12 kt will
become NE and ease to 5-7 kt later this evening. Winds will then
switch to the southwest Tuesday afternoon and increase to 8-12
kt.
&&
.MARINE...
A brief period of offshore flow Tuesday will accompany
a thermally induced surface trough as it noses northward along
the Oregon coast overnight. A system passing midweek will bring
a 30-40% chance of showers over the interior waters. While winds
for most waters will remain light through the week, there will
continue to be pushes of winds (likely greater than 20 kt)
through the Strait of Juan de Fuca at times. Wednesday continues
to look like the strongest period with a 75% chance of gusts 25
knots or stronger through the central and eastern strait. Seas
will hold around 4-6 ft through the week, with a brief bump to
6-8 ft with the midweek system.
&&
.HYDROLOGY...
The daily hydrology discussion has ended until the
start of the next rainy season; it will only be updated during
this time as needed.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...None.
&&
$$
NWS SEW Office Area Forecast Discussion