Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
742
FXUS66 KSEW 270930
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
230 AM PDT Sat Jun 27 2026
.SYNOPSIS...
A broad upper trough will remain over the area well into next
week with a series of low pressure systems maintaining below
normal temperatures and periodic chances of showers.
&&
.SHORT TERM /TODAY THROUGH MONDAY/...
A convergence zone continues to affect Snohomish and Skagit
counties early this morning. This is expected to diminish toward
dawn as low level onshore flow begins to relax somewhat. A
closed upper level low will gradually shift southward across
Western Washington today with the focus for shower activity
shifting to higher terrain of the central/south Cascades and
portions of the Southwest Interior. Some areas around Puget
Sound might catch a few peeks of sun this afternoon, but
temperatures will remain a little below normal.
Models are latching on to a compact closed upper low slipping
southward along the coast on Sunday. This system doesn`t look
like it will produce much of any precip, but it will ensure that
we see plenty of cloud cover with temperatures continuing their
recent trend of several degrees below normal for the end of
June. Broad upper level ridging centered well offshore attempts
to briefly nose into the area on Monday, but continued onshore
flow and meager height recoveries point toward mostly cloudy
and cool conditions persisting.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
Strong upper level ridging centered well offshore around 150W
and over the eastern half of the lower 48 will keep a mean
upper trough position anchored over the West Coast through much
of the extended forecast period. This keeps the door open for
additional upper level systems to dip southward from British
Columbia maintaining below normal temperatures and producing
periodic chances for showers.
27
&&
.AVIATION...
Scattered shower activity is being observed along the coast, over
the Cascades, and the north Puget Sound, associated with a PSCZ. The
PSCZ continues to bring IFR/MVFR conditions and intermittent showers
to KPAE. Expect the PCSZ to wind down around 15Z as a cold upper-
level low will slides southeastward into western Washington Saturday
morning. This will bring a renewed threat for showers across western
Washington late Saturday morning through the afternoon. The best
chances (50-80%) will be in the mountains with a 30-50% chance
around Puget Sound terminals. This also comes with a 15-25% chance
for thunderstorms. The highest confidence for thunderstorms will be
primarily for the southern Puget Sound (Thurston County, western
Pierce County) and Lewis County where the cooler temperatures aloft
associated with the center of the upper-level low supports taller
storms. A mix of MVFR and VFR conditions are expected through the
period with MVFR conditions favored through 17-18Z before improving
to VFR. Winds will be out of the south 6-10 kts this morning and
gradually shift to the west through the late morning and then to the
west-northwest this afternoon.
KSEA...VFR ceilings currently being observed with a 50% chance for
MVFR ceilings between 13-17Z. There is high confidence for VFR
conditions to return after 17Z and remain VFR through the evening.
Probabilities for ceilings below 2000 feet increase to 50-80% after
09Z Sunday. There is a slight chance (15%) for thunder Saturday
afternoon, but confidence is not high enough to include it in the
TAF. Southerly winds 5-9 knots will shift to the southwest around
17Z and then to the west-northwest around 00Z-05/06Z before shifting
back to the south-southwest. /vmt
&&
.MARINE...
The overall pattern over the next several days will feature a
broad surface ridge centered well offshore with lower pressure
across the interior promoting onshore flow. This will lead to
gusty northwesterlies over the outer coastal waters and the
development of steep, choppy seas later today and into early
next week. In addition, the central and east Strait of Juan de
Fuca will likely see diurnally driven increases in westerlies
reaching small craft advisory strength on a routine basis. The
offshore ridge is expected to weaken toward late next week
allowing for lighter winds and subsiding seas.
27
&&
.FIRE WEATHER...
Little in the way of fire weather concerns remain in the picture
well into the week ahead with upper troughing maintaining cool
conditions, high RH, and periodic chances for shower activity.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory from 5 PM this afternoon to 2 AM PDT
Sunday for 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 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