Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
091
FXUS66 KSEW 012146
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
246 PM 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 /TONIGHT THROUGH WEDNESDAY NIGHT/...Warm and dry
weather on tap through Tuesday due to high pressure and
offshore flow. Highs on Tuesday will reach the 80s to low 90s
with warmest spots away from the sound. We`re expecting minor to
moderate HeatRisk for this event. The air mass will be dry as
well with daytime min humidities in the 20s and 30s - keeping
fire weather conditions elevated. However, gusty east winds will
peak in the morning hours and not coincide with the
warmest/driest conditions.
Wednesday brings cooler conditions with a trough and a return
of onshore flow. Forecast highs are in the 60s to lower 70s and
closer to average. The trough will bring a chance of showers and
thunderstorms to the Cascades where instability is the greatest.
Showers will taper down Wednesday night. 33
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...A deep upper low, off BC,
keeps western WA cool moving into the weekend. Highs will track
a few degrees cooler than normal and in the lower to mid 60s.
Expect lows in the 40s and 50s. Showers increase on Saturday as
the low spins overhead. The air mass is slightly unstable for a
chance of thunderstorms in the interior and Cascades. Showers
with a convergence zone are expected too (over the north/central
sound). A ridge brings some drying and slightly warmer
conditions on Sunday. A weak, splitting front approaches the
coast on Monday. 33
&&
.AVIATION...Northerly flow aloft tonight will become westerly on
Tuesday as an upper ridge over the region gradually shifts eastward.
Weak low level offshore flow will turn onshore late in the day on
Tuesday. VFR conditions will prevail through Tuesday.
KSEA...VFR. Surface winds northerly 8 to 12 knots with occasional
higher gusts this afternoon will ease this evening and become light
northeasterly tonight. Winds will shift west/northwesterly Tuesday
afternoon before backing southwesterly Tuesday night.
&&
.MARINE...Thermally induced low pressure will expand northward
into the area tonight for light offshore flow. The thermal trough
will shift inland Tuesday afternoon for the commencement of onshore
flow. A dissipating frontal system will reach the waters on
Wednesday. Surface high pressure will rebuild across the waters
Wednesday night into Thursday for stronger westerlies in the strait.
A broad trough and associated front will cross the waters Friday and
Saturday.
Coastal seas are expected to remain below 10 feet through the period.
27
&&
.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.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...None.
&&
$$
NWS SEW Office Area Forecast Discussion