Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
573
FXUS66 KSEW 291550
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
850 AM PDT Mon Jun 29 2026
.SYNOPSIS...
A broad upper level trough will continue to produce unsettled
and cool conditions across Western Washington into midweek along
with chances for mainly mountain showers. Drier conditions and
a modest warming trend are expected for the upcoming holiday
weekend with a weak ridge of high pressure aloft.
&&
.SHORT TERM /TODAY THROUGH WEDNESDAY/...
No significant updates to the forecast this morning. Stratus
will prevail through much of the day, with clouds trying to
break late this afternoon. This will keep temps moderated,
currently in the mid 50s, reaching the mid to upper 60s this
afternoon. 62
Western Washington remains under the influence of
broad upper troughing aloft and low level onshore flow. At the
risk of sounding like a broken record, the forecast into midweek
will largely mimic what we saw yesterday. Night and morning low
clouds will stubbornly give way to a few peeks of late day sun
over the interior lowlands and temperatures will be held several
degrees below seasonal averages. A series of weak disturbances
moving through the trough will occasionally kick off a shower
over the higher terrain or squeeze out some coastal drizzle, but
otherwise mainly dry conditions will prevail.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
The long term forecast period begins with much the same trend of
cool unsettled conditions. A few of the operational model runs
attempt to bring a weakening frontal system into the area on
Thursday, but it may well encounter a building ridge offshore
and result in little if any precipitation away from the coast
and Olympic Peninsula.
As we move toward the upcoming holiday weekend, ensembles are
continuing the trend of previous runs which have upper
troughing retreating into the northern Gulf of Alaska and at
least some upper ridging rebuilding into the Pacific Northwest.
There`s still a decent spread in solutions with regard to the
strength of the ridging, but the overall ensemble averages
suggest a return to temperatures near, if not a little above,
seasonal norms for early July along with dry conditions.
27
&&
.AVIATION...
Broad upper troughing over the interior West will continue to
maintain northwesterly flow aloft over Western Washington. MVFR
to IFR cigs prevail across western Washington this morning, but
is expected to slowly lift throughout the morning to low-end
VFR by the afternoon for interior terminals. Clouds will likely
try to break but ceilings are not expected to fully scatter. Ceilings
will likely deteriorate back to low MVFR or localized IFR once
again tonight and through much of Tuesday morning.
KSEA...MVFR with occasional periods of IFR this morning.
Expecting slow improvement through the morning, with low-end VFR
after around 21Z. Ceilings may become broken but not expecting
full scattering. Ceilings will fall back to MVFR late tonight
and continue through Tuesday morning. Surface winds south to
southwesterly 7 to 10 knots rising to 9 to 12 knots later this
evening.
27/62
&&
.MARINE...
A broad surface ridge centered well offshore and lower pressure
across the interior will remain the dominant weather pattern
into midweek. This will maintain onshore flow with gusty
northwesterlies and steep seas for the coastal waters. Diurnally
driven westerly pushes will occur in the Strait of Juan de Fuca
as well. The offshore ridge is expected to weaken during the
later half of the week as a broad surface low approaches the
central British Columbia coast. This will weaken onshore flow
allowing winds over the coastal waters to ease and seas subside.
27
&&
.FIRE WEATHER...
Little in the way of fire weather concerns remain in the
picture into the week ahead with upper troughing maintaining
cool conditions, high RH, and periodic chances for shower
activity. A trend toward more seasonable temperatures is
indicated toward late week, but a significant warm and dry spell
is not expected in the next 7 days.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory from 5 PM this afternoon to 2 AM PDT
Tuesday for Central U.S. Waters Strait Of Juan De Fuca-
East Entrance U.S. Waters Strait Of Juan De Fuca.
Small Craft Advisory until 5 PM PDT Tuesday 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