Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
368
FXUS66 KSEW 261624
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
924 AM PDT Fri Jun 26 2026
.SYNOPSIS...
A weak frontal system will move inland across Western Washington
this morning. An upper level trough will then settle over the
region tonight into Saturday maintaining cool and unsettled
conditions. The trough will shift eastward later Sunday allowing
drier conditions to develop into Monday. Another system is
expected to drop southward into the area around the middle of
next week for continued cool temperatures and another chance for
showers.
&&
.SHORT TERM /TODAY THROUGH SUNDAY/...
A weak front will move onshore across the area this morning
with areas of light rain. Onshore flow will increase behind it
for breezy conditions around Puget Sound and through the strait.
This will allow a decent convergence zone to develop late this
afternoon into tonight. Some modest instability this afternoon
may lead to an isolated thunderstorm or two with CAPE values
generally 250 J/kg or less. The best chances for any thunder
(around 25 percent or so) will be in the convergence zone late
this afternoon and evening. The convergence zone should diminish
by Saturday morning as an upper trough settles over the region.
The trough will gradually shift southward across the area
through the day on Saturday keeping the threat of a few showers
in the forecast and holding temperatures a handful of degrees
below normal. By Saturday afternoon and evening, shower chances
will gradually become confined to the Southwest Interior and
higher terrain in the Cascades. The upper low is expected to
shift eastward into the northern Great Basin and Rockies on
Sunday allowing most of Western Washington to dry out. Heights
only recover modestly and low level onshore will remain in place
for continued cool conditions and plenty of cloud cover.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Model ensembles are in relative good agreement with keeping a
mean trough position along the west coast through much of next
week. They differ somewhat in minutiae as one might expect, but
the overall pattern favors continued cool, unsettled conditions
with perhaps another upper low dropping southward toward the
region mid to late week for additional light precip.
27
&&
.AVIATION...
Latest radar shows scattered showers moving across western
Washington. Intermittent rain showers will continue through the
morning becoming more isolated in the afternoon. Ceilings are
gradually improving already this morning, with a mix of MVFR and IFR
cigs. Improvement expected later this afternoon to VFR for the
interior terminals and MVFR along the coast. A small chance (30%)
remains for MVFR cigs to linger this afternoon along the Kitsap
Peninsula and Strait of Juan de Fuca terminals. A Puget Sound
Convergence Zone (PSCZ) is anticipated to develop in Snohomish
County after 00Z, bringing higher confidence for showers at KPAE
Friday evening. There is also a 15-20% for isolated thunderstorms
for KSEA north and east to the Cascades between 18Z Friday and 06Z
Saturday. Best chances will be with the PSCZ, but confidence is not
high enough to include in any TAFs. Southerly winds will largely
prevail with gusts up to 20 knots this afternoon, with northerly
winds within the PSCZ.
KSEA...MVFR cigs this morning with gradual improvement to VFR
expected this afternoon. Light rain showers will continue on and off
through the morning with chances decreasing in the afternoon. There
is moderate confidence (50% chance) for MVFR conditions after 06z
Saturday. In addition, there is a slight chance (30%) for IFR cigs
after 10z Saturday. There is good agreement among ensembles that the
convergence zone will remain north of SEA this evening. Southerly
winds 6-10 knots this morning increasing to 8-13 knots with gusts up
to 20 kt this afternoon.
&&
.MARINE...
A weak front will move inland early today. Onshore will
increase behind the front this afternoon into tonight with small
craft advisory winds expected in the central/east strait as well
as Puget Sound. Broad high pressure will remain centered well
offshore into midweek with lower pressure over the interior for
varying degrees of onshore flow. Increasing northwest flow will
lead to gusty winds and choppy seas out the outer coastal waters
this weekend into early next week.
27
&&
.FIRE WEATHER...
Main fire weather concerns revolve around a marginal lightning
threat today with thunderstorm probabilities around
15-20%...greatest around the convergence zone. Otherwise, cool
and unsettled conditions prevail over the next 7-days alongside
a very low lightning risk.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory from 3 PM this afternoon to 2 AM PDT
Saturday for Central U.S. Waters Strait Of Juan De Fuca-
East Entrance U.S. Waters Strait Of Juan De Fuca.
Small Craft Advisory until 8 PM PDT this evening for Puget
Sound and Hood Canal.
Small Craft Advisory from 2 PM Saturday to 5 PM PDT Sunday for
Coastal Waters From Cape Flattery To James Island 10 To
60 Nm-Coastal Waters From James Island To Point Grenville
10 To 60 Nm-Coastal Waters From Point Grenville To Cape
Shoalwater 10 To 60 Nm.
&&
$$
NWS SEW Office Area Forecast Discussion