Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
523
FXUS66 KSEW 260326
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
826 PM PDT Sat Apr 25 2026
.SYNOPSIS...
Mostly dry and mild conditions will continue over the next week
across western Washington as an upper level ridge remains over
the region.
&&
.SHORT TERM /TODAY THROUGH MONDAY NIGHT/...
Western Washington is wedged between a broad upper trough over the
Northern Rockies and an upper ridge centered well offshore. The end
result is northerly flow at the surface and aloft. The air mass is
cool and quite dry with widespread dew points in the 20s. This will
allow temperatures to fall to near freezing across south Puget Sound
and the Southwest Interior overnight. Hence, there is a frost
advisory in effect. The overall synoptic pattern doesn`t change
significantly on Sunday apart from a slight bump in heights and
lighter north flow near the surface. We`ll see another mostly sunny
day and slightly warmer temperatures. A weak disturbance will
produce some cloud cover and cooler temperatures Monday and Tuesday,
but stronger upper ridging is still on track to rebuild midweek
allowing a few spots south of Seattle to make a run at 70 degrees.
No public updates expected tonight. 27
Northerly flow aloft will continue over western Washington through
the weekend as an upper level ridge builds offshore.
This will maintain mostly dry conditions across the region with
a warming trend into Sunday. However, mostly clear skies
tonight into Sunday morning may allow for continued cold low
temperatures which may cause frost to develop along the Puget
Sound southward. Otherwise, western Washington will see warming
conditions under mostly sunny skies into Sunday.
Temperatures cool several degrees on Monday as a weak shortwave
passes over the area, bringing increased onshore flow. This
system will bring cloudy skies to much of the region, with
chances for light showers over higher terrain.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
Northwest flow will develop aloft on Tuesday as a high pressure
ridge builds offshore. This will allow for another day of near-
normal temperatures and cloudy skies, with chances for showers
continuing over the mountains. The ridge axis will shift inland
on Wednesday and Thursday, bringing warming and clearing to the
region, with temperatures nearing 70 degrees east and south of
the Puget Sound on Thursday.
By Friday, a cutoff low is forecast to develop along the west
coast, but models show large differences over the placement of
the low. This will influence conditions across western
Washington, so for now the forecast for Friday and beyond
remains uncertain.
15
&&
.AVIATION...An upper ridge will remain offshore through the weekend,
with troughing over the Intermountain West. This will result in
continued northerly flow aloft. Light to weak onshore flow tonight
into Sunday morning. Predominantly clear skies with VFR for the
interior sites through Sunday. There remains approximately a 35 to
40% chance of LIFR/IFR cigs for KHQM generally between 12 to 18z on
Sunday. Onshore flow will then increase Sunday night into Monday for
a more widespread stratus push inland. North winds will weaken this
evening, becoming light tonight into Sunday. W/NW winds increase
Sunday afternoon.
KSEA...Clear conditions expected through the TAF period. North winds
5 to 10 kts this evening will decrease below 5 kts mainly after 06-
07z. NW winds increase again Sunday afternoon. JD
&&
.MARINE...
High pressure will remain over the coastal waters, with lower
pressure inland. North flow (offshore at times) will transition to
more of an onshore pattern early next week. Models have a couple
pushes down the Strait of Juan de Fuca Sunday evening and Monday
evening, but the probability of gusts reaching small craft advisory
thresholds is low at this time. The outer coastal waters may see
breezy gusts up to 20 kt Monday/Tuesday, with a possible system end
of the week producing breezy winds across more of the waters.
Additionally, low clouds/fog Sunday morning along the Pacific Coast
may reduce visibilities at times to mariners.
Seas this weekend hold around 4-6 ft, and increase to 6-8 ft Monday
through next week.
HPR
&&
.HYDROLOGY...
No river flooding is expected over the next 7 days.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Frost Advisory from 11 PM this evening to 10 AM PDT Sunday for
City of Seattle-Lowlands of Lewis and Southern Thurston
Counties-Lowlands of Pierce and Southern King Counties-
Olympia and Southern Puget Sound-Southern Hood Canal.
PZ...None.
&&
$$
NWS SEW Office Area Forecast Discussion