Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
272
FXUS66 KSEW 090857
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
157 AM PDT Thu Jul 9 2026
.SYNOPSIS...
Weak high pressure aloft will lead to seasonal temperatures and
dry conditions across Western Washington today. A weak front
will bring increasing clouds and cooler temperatures to the
region Friday into Saturday along with a chance for a little
rain. High pressure will strengthen once again for warmer and
dry conditions Sunday through Tuesday. Cooler conditions return
by the middle of next week as onshore flow increases.
&&
.SHORT TERM /TODAY THROUGH SATURDAY/...
Mostly high level clouds are drifting across the area this
morning in zonal flow aloft while onshore flow near the surface
begins to ease. With less in the way of low cloud coverage this
morning, high temperatures across interior areas will see a
little boost. Onshore flow ramps up once again late today ahead
of a weak front that will reach the area Friday afternoon into
Friday night. As with most fronts this time of year, the best
precip chances will be restricted to the Olympic Peninsula and
North Interior, but it`s not out of the question to see a few
sprinkles reach Seattle metro...just don`t hold your breath on
that. We will, however, see cooler temperatures and plenty of
cloud cover that will linger into Saturday as a trailing upper
trough comes onshore before lifting northeastward into British
Columbia.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
For Sunday through Tuesday, we`ll be on the northwest periphery
of a monster upper ridge building over the Rockies and Northern
Great Plains. This will give us a mini warming trend with
temperatures peaking in the lower (or mid) 80s in the warmest
spots on Monday. Ensembles maintain anomalous upper troughing
along the British Columbia coast into the middle of next week,
but there`s some disparity with regard to it`s depth. We`re
quickly approaching the climatologically driest and warmest
portion of the year in Western Washington. Most troughs
approaching from the northwest by mid-July do little more than
initiate increasing onshore flow to cool us down. Given that, a
good day 7 forecast leans toward near climo temps and dry
conditions.
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&&
.AVIATION...
Onshore flow continues through Thursday, though widespread stratus
formation is less likely. There`s a 30-50% chance of MVFR/IFR cigs
returning along the coast after 09z Thu, though only a 20-40% chance
it will push as far inland as KHQM. Additionally, there`s a 15-30%
chance of some marginal MVFR ceilings reaching inland to Seattle by
daybreak. Where stratus does form, more rapid clearing is expected
Thursday with VFR conditions for most TAF sites by 17-19z. A
stronger marine push is expected Thursday night into Friday morning
with an 80% chance of at least MVFR cigs developing along the coast
by 06-08z Fri and a 40-60% chance of widespread MVFR cigs pushing
inland to Seattle by daybreak Friday.
Winds have settled overnight except for gusts up to 20-25 kts along
the Strait of Juan De Fuca, impacting KCLM through Thursday.
Elsewhere, winds remain lighter, generally less than 8 kts.
KSEA...A pocket of stratus has lingered near the terminal since
Wednesday evening, producing a ceiling deck around 3500-4500 ft.
There`s a 15-25% chance of marginal MVFR ceilings by daybreak.
Ceilings are expected to lift above 5000 ft by 16-18z Thu with a
scattered to broken high cloud deck lingering. There are better
chances (40-60%) for widespread MVFR cigs to return by 12-15z Fri.
Winds will be light through the period, from the southwest through
Thursday morning, becoming west to northwest in the afternoon.
&&
.MARINE...
Surface high pressure over the coastal and offshore waters will
remain in place today before weakening on Friday as a weak
surface low shifts southward toward to just west of north
Vancouver Island. An associated weak frontal system will cross
the waters Friday afternoon into Friday night with little
impact. High pressure rebuilds over the coastal waters Sunday
into Monday. Diurnally driven increases in westerlies can be
expected in the Strait of Juan de Fuca each the next several
days.
27
&&
.FIRE WEATHER...
The current onshore pattern will continue through the weekend
which will lead to continued excellent nightly RH recoveries. A
ridge of high pressure briefly rebuilds into the region early
next week. While the onshore pattern will largely remain in
place, warmer daytime temperatures and clear skies will likely
lead to RH values dipping into the 30s and 20s, with the lowest
values in the south interior and Cascades. This will allow fine
fuels to continue to dry with elevated fire weather conditions.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 5 AM PDT early this morning for
Central U.S. Waters Strait Of Juan De Fuca-East Entrance
U.S. Waters Strait Of Juan De Fuca.
&&
$$
NWS SEW Office Area Forecast Discussion