Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
038
FXUS66 KSEW 311034
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
334 AM PDT Sun May 31 2026
.SYNOPSIS...
Upper level high pressure will continue to gradually build
across the Pacific Northwest, resulting in gradually warming
temperatures through the early part of this week. Temperatures
will peak on Tuesday, resulting in Minor to Moderate HeatRisk.
Onshore flow will increase Wednesday as the upper ridge weakens,
followed by the next disturbance approaching Western Washington
late this week.
&&
.SHORT TERM /TODAY THROUGH TUESDAY/...
Clear skies and mostly light winds across much of western Washington
will allow for a relatively cool start to the morning today, with
lows in the low to mid 40s. Some more outlying areas along the coast
and the southwest interior may dip down to the upper 30s, briefly.
Clear skies from a building upper level trough offshore will allow
temperatures to rise up to the mid 60s to low 70s today.
Temperatures will warm successively each day, being enhanced by light
offshore flow developing from a weak surface thermal trough. Highs
on Monday will rise into the 70s to near 80 on Monday. Tuesday will
be the warmest day as the upper level ridge axis moves overhead over
the region and the surface thermal trough moves inland. With high
temperatures in the upper 70s to near 90, as well as lows in the mid
to upper 50, this corresponds to Minor (Yellow) HeatRisk for the
coastal areas and northern interior locations, as well as 50-60%
chance of reaching Moderate (Orange) HeatRisk through the Chehalis
Valley, South Sound, interior portions of southwest Washington, and
areas of the Seattle Metro away from the water.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Ensemble guidance continues to remain consistent for the midweek
period with a flattening upper ridge and the thermal low
pressure sliding eastward. This will bring a return of onshore
flow at the lower levels Wednesday and Thursday, with
temperatures returning closer to seasonal normals and relative
humidities increase. The next disturbance then is likely to
move into the region late the week, bringing a return of
increasing clouds and a return of precipitation toward next
weekend.
&&
.AVIATION...West to northwesterly flow continues aloft as an upper
level ridge builds offshore today. VFR conditions prevail through
the TAF period with mostly clear skies. Some scattered mid-level
clouds will hang around this morning but remain above 050-070 kft.
Light north/northwest winds will increase during the day to 8-15 kt,
decreasing to around 5 to 10 kt tonight and becoming more
northeast/easterly.
KSEA...VFR conditions prevail through the TAF period. NE winds 8-12
kt early this morning becoming NW 10-15 kt during the day,
transitioning back to NE tonight.
62
&&
.MARINE...
Northwesterly flow continues to prevail over the coastal waters as
high pressure remains offshore with low pressure over land. Westerly
winds of up to 20-30 kt continues through the Strait of Juan de
Fuca and into Admiralty Inlet, but remains on track to ease
early this morning.
High pressure will briefly build this evening, allowing winds over
the coastal waters to bump up to 15-20 kt with gusts up to 25 kt.
This will allow seas to build up to around 6-8 ft, and they will be
steep with a dominant period of around 6 to 7 seconds. This will
ease early Monday morning as winds also ease accordingly.
Conditions become more tranquil Monday into Tuesday as high pressure
weakens and is replaced by weak thermal troughing along the coast,
which may briefly turn winds more offshore early Monday, and then
again Monday night into early Tuesday. Onshore flow will resume
during the day on Tuesday as the thermal trough is forced eastward.
Onshore flow will become stronger Wednesday and through the rest of
the week as weak disturbances move across the coastal waters. An
extended period of SCA conditions is expected through the strait,
with the best chance of gale force winds being Thursday
afternoon and evening.
Seas 5 to 6 ft today will increase to 6 to 8 ft with a dominant
period of around 6 or 7 seconds tonight into early Monday. Seas fall
Monday back to around 4 to 6 ft and remain around there through the
week.
62
&&
.FIRE WEATHER...
An upper level ridge will setup a drier pattern on Monday and
Tuesday, with maximum temperatures reaching into the 80s (with a
few spots touching 90). Expect a weak thermal trough to build
north over the region, with some light offshore flow developing
as a result. Winds appear to remain rather light, but a few gusts
to 15 mph near the Cascades remain possible. This will help to
bring drier conditions in to the area with daytime RHs down approaching
critical thresholds. This stretch appears short-lived, with a
resumption of onshore flow bringing higher humidities for the
second half of the week.
&&
.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...Small Craft Advisory until 7 AM PDT this morning for Admiralty
Inlet-Central U.S. Waters Strait Of Juan De Fuca-East
Entrance U.S. Waters Strait Of Juan De Fuca.
Small Craft Advisory from 2 PM this afternoon to 2 AM PDT
Monday for Coastal Waters From Cape Flattery To James
Island 10 To 60 Nm-Coastal Waters From Cape Flattery To
James Island Out 10 Nm-Coastal Waters From James Island
To Point Grenville 10 To 60 Nm-Coastal Waters From James
Island To Point Grenville Out 10 Nm-Coastal Waters From
Point Grenville To Cape Shoalwater 10 To 60 Nm-Coastal
Waters From Point Grenville To Cape Shoalwater Out 10 Nm.
&&
$$
NWS SEW Office Area Forecast Discussion