Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
609
FXUS66 KSEW 010935
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
235 AM PDT Mon Jun 1 2026
.SYNOPSIS...
An upper level ridge will build across the Pacific Northwest
early this week, resulting in warming temperatures through
Tuesday. Temperatures will peak on Tuesday, resulting in Minor
to Moderate HeatRisk as well as much lower daytime relative
humidity values. Onshore flow increases Wednesday as the upper
ridge weakens. The next disturbance approaches Western
Washington later in the week.
&&
.SHORT TERM /TODAY THROUGH WEDNESDAY/...
Mostly clear skies and light winds prevail across western Washington
this morning, through temperatures much warmer compared to yesterday-
-in the mid 40s to low 50s. High clouds will begin to move in from
the east this afternoon. Temperatures remain on track to warm into
the 70s across much of the area, with some locations reaching close
to 80 such as the inland coast, Southwest Interior, and Cascade
Valleys.
Offshore flow developing this afternoon and tonight will keep lows
much warmer, staying in the low to mid 50s. The warming trend peaks
on Tuesday, with highs ranging from the upper 70s near the water to
the mid to upper 80s through the interior.
More inland locations may get close to 90. Remember the waters are
cold, with many river and lake water temperatures in the 50s and
60s. Ocean water temperatures remain the low 50s.
The pattern changes on Wednesday as an upper level shortwave trough,
as well as weak surface frontal system traverse the area. This
system will bring in increased cloud cover, locally breezy
conditions with stronger onshore flow, and much cooler temperatures
with highs returning into the low to mid 70s, and 60s along the
coast. Precipitation chances across much of the area will be
minimal, however, with some upper-level instability present, there
is a 15% chance of showers and thunderstorms across the Cascades on
Wednesday afternoon/evening.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Onshore flow continues across Western Washington late Wednesday
into Thursday with temperatures returning closer to seasonal
normals. Latest ensemble guidance continues to consistently
bring the next deeper upper level trough into the region later
in the week and into the weekend. This will maintain continued
cooler and cloudier conditions, along with rain chances at
times. As the core of the cooler temperatures aloft pass
overhead on Saturday, we will see around a 15% chance of an
isolated thunderstorm or two across much of the area.
&&
.AVIATION...
Northerly flow aloft continues with an upper level ridge just
offshore. VFR conditions prevail through the TAF period. Mostly
clear skies continue this morning, with high clouds moving in this
afternoon. Light NE to calm winds will become more N/NW during the
day, up to around 5 to 10 kt. Winds transition to more NE/E tonight,
after 06Z Tue.
KSEA...VFR conditions prevail through the period with increasing
high clouds this afternoon. NE winds 6 to 10 kt becoming more NW
after 18Z, up to 8 to 12 kt with occasional gusts 18-20 kt this
afternoon. Winds ease but become more NE to E tonight.
62
&&
.MARINE...
High pressure will begin to weaken over the coastal waters as a weak
thermal trough develops and works up along the coastline.
Winds will remain north/northwest today, but will briefly switch to
easterly overnight along the coast and through the Strait.
The thermal trough then gets forced inland Tuesday by an incoming
system, allowing winds to return to northwesterly during the day
Tuesday.
A weak front will traverse the area waters on Wednesday, allowing
for stronger onshore flow. High pressure will return in its wake,
allowing for enhanced wind through the Strait of Juan de Fuca
beginning Wednesday. An extended period, through late week, of Small
Craft Advisory winds is likely. There also remains a 40-70% chance
for gale force gusts on Thursday evening. Winds will slowly ease
over the weekend as a broad low pressure system moves through the
area waters.
Seas generally remain in the 4 to 7 ft range through the week.
62
&&
.FIRE WEATHER...
An upper level ridge will setup a dry and warm pattern through
Tuesday across the region with light offshore flow developing as
a weak thermal trough builds north over the Puget Sound region.
Tuesday remains on track to be the warmest day, with daytime
high temperatures reaching into the 80s and a few spots touching
90. Winds still appear to be relatively light, but a few gusts
to 15-20 mph near the Cascades and over the exposed ridgetops remain
possible. Poor overnight recoveries are expected tonight into
Tuesday morning, with daytime RHs Tuesday likely to approach
20%. However, this stretch appears short-lived, with a resumption
of onshore flow bringing higher humidities for the second half
of the week. Cullen
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...None.
&&
$$
NWS SEW Office Area Forecast Discussion