Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
466
FXUS66 KSEW 232209
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
309 PM PDT Thu Jul 23 2026
.SYNOPSIS...
Scattered thunderstorms continue offshore, with the potential
for additional development this afternoon. An upper level trough
offshore will then push inland over the weekend, bringing
cooler temperatures to the area and additional chances of
showers. Troughing will persist through early next week,
allowing for temperatures to trend just below to near normal.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
Satellite and radar continue to show scattered thunderstorms
along portions of the Washington coast and across the coastal
waters. These will continue to move to the north-northwest this
afternoon. Additional development will be possible this
afternoon, with the best chances being over the Cascades and
Olympics. Showers and thunderstorm chances should ease tonight
as the trough offshore beings to lift northward. Marine stratus
will likely fill back in tonight, allowing for low temperatures
to reach the mid 50s to near 60. Stratus should give way to
mostly sunny skies on Friday, allowing for high temperatures to
bump up a bit compared to today, reaching back into the low to
mid 80s across the interior, with 70s elsewhere.
The upper trough offshore finally traverses the area Friday
night into Saturday, bringing stronger onshore flow and more
clouds, as well as chances for showers along the coast and the
mountains. This will also help to push high temperatures below
normal, with high temperatures in the mid 70s.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Chances for showers will continue Saturday night into Sunday as
another shortwave trough moves through the area. Temperatures on
Sunday similar to Saturday, in the mid 70s. Looking forward
into next week, upper level troughing remain the dominant
influence across the area as several systems move down from the
Gulf of Alaska. Some model solutions show the upper level high
over the Four Corners region retrograding westward, which may
allow highs to warm towards the end of the week, otherwise
temperatures generally remain around climatological normals
with mostly dry conditions after Monday.
&&
.AVIATION...
An upper level low will continue to spin offshore the Pacific
Northwest tonight. This low has been responsible for bringing
mid level moisture over western WA this afternoon- and showers
and thunderstorms to portions of the coast and Olympic Peninsula.
Thunderstorm chances will remain possible through the remainder
of the afternoon, but will mainly remain confined to the Cascades,
Olympics, and the coast. Latest guidance continues to suggest
showers tapering between 00-03Z. Satellite this afternoon shows
some low clouds lingering across the central and south Cascades
and along the coast. Expect another strong push of onshore flow
in the low levels to bring marine stratus inland to the Puget
Sound terminals by 12Z Friday for another round of MVFR to
localized IFR conditions. Expect conditions to gradually improve
back to VFR for the interior terminals around 18Z Friday as
stratus retreats back to the coast. Southwesterly winds will
generally persist between 8-12 kts (with some gusts to 20 kt)
across the interior terminals through this evening, before
easing and becoming light and variable tonight around 06Z.
KSEA...VFR conditions this afternoon with some FEW and SCT low
to mid clouds. Expect another round of stratus to push into the
terminal by 12Z Friday and lower conditions back to MVFR. West-
southwesterly winds will persist at 8-12 kt through this
evening, before easing and becoming light around 06Z.
14
&&
.MARINE...
A low pressure system offshore will continue to bring chances of
showers and thunderstorms to the coastal waters through this
afternoon. Latest radar this afternoon shows a line of scattered
thunderstorms currently moving northward across the central and
northern coastal water zones. Gusty winds, lightning, reduced
visibilities, and brief heavy downpours are likely within the
vicinity of these storms.
A low pressure system will remain offshore the Pacific Northwest
on Friday, before tracking back into the area and dissipating
on Saturday. Onshore flow will prevail over the next few days,
with strongest winds expected to be along the Strait of Juan de
Fuca. Another low pressure system will track southward from Gulf
of Alaska and will stall a frontal boundary offshore on Saturday
before it moves inland on Sunday night. This may bring some
small craft southerlies to portions of the area waters over the
weekend. Another front will follow on Tuesday.
Seas will generally range between 4-7 ft over the coastal
waters on Friday. A brief uptick in seas to 6-8 ft will be
possible on Saturday, before seas subside back to 4-6 ft again
on Sunday. Seas will then persist within the 4 to 6 ft range
into early next week.
14
&&
.FIRE WEATHER...
The Red Flag Warning for lightning and gusty outflow winds continues
as the thunderstorm chances will remain into this evening. There
have been several reports so far of fire starts from yesterday`s
lightning which number in the hundreds of flashes overland. Rainfall
with the storms was sparse. Where it did fall, it was mostly just a
few hundredths to less than a tenth of an inch. The strongest
concentration of thunderstorms and heaviest rain was along the
Cascades from the southern Lewis County border to the King -
Snohomish County border with amounts ranging from about a quarter to
six tenths of an inch.
Overhead clouds and the onshore flow today has brought low clouds and
stratus that is stubborn to burn off and hampering firefighters
efforts to locate and attack the new fire starts. The cooler
temperatures and higher humidities today will give way to warm and
dry conditions Friday as the upper ridge expands over the area once
again. This will be short lived as the low center off the coast
makes its way over the region though dissipating in the process. the
result will be cool temperatures and shower chances through the
weekend into the first part of next week easing fire weather
concerns. Additional thunderstorms are not likely but can`t be
ruled out at this time. JBB
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Red Flag Warning until 10 PM PDT this evening for Black Hills
and Southwest Interior Lowlands-Central Coastal Lowlands-
East Portion of the Olympic Mountains-North Coastal
Lowlands-North and Central Coastal Strip-West Portion of
the Olympic Mountains-West Slopes of the Central Cascades
Generally above 1500 Feet.
PZ...Small Craft Advisory until 5 AM PDT Friday 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