Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
861
FXUS66 KSEW 270340
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
840 PM PDT Sun Apr 26 2026
.SYNOPSIS...
Mostly dry and mild conditions will continue through much of
next week across western Washington as an upper level ridge
remains situated over the region. Troughing is on track to
return by next weekend, bringing cooler conditions and increased
chances for mountain showers.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
An onshore push is well underway this evening with the marine layer
marching inland to just west of Shelton as of 830 PM PDT. Stratus
will fill in across much of the interior by early Monday morning. As
a result, high temperatures tomorrow will cool several degrees under
mostly cloudy skies. Tuesday remains a virtual carbon copy before
upper ridging rebuilds Tuesday night into Wednesday with low level
flow turning more northerly again. Sunshine returns Wednesday and
Thursday. Current forecasts are on track. Previous discussion
follows with updated aviation section. 27
Northerly flow aloft has brought another dry day across western
Washington, with temperatures on track to peak several degrees above
normal in the upper 60s to lower 70s. High pressure will continue to
build onshore tonight into Monday, generating onshore flow that will
allow low clouds to develop along the coast and filter inland
towards the Puget Sound Monday morning. The onshore flow will bring
in cloudy skies across western Washington, limiting temperatures
into the upper 50s to lower 60s. This system will also bring a
slight chance of light showers along the coast and over the
mountains. More of the same will continue on Tuesday, with a degree
or two of cooling under mostly cloudy skies.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
An upper level ridge building offshore will drift closer to the
Washington coastline on Wednesday and Thursday, bringing in a
warming trend with clearing skies. The ridge axis will shift
inland on Thursday, bringing the warmest temperatures of the
week. Highs will peak in the upper 60s to mid 70s across the
lowlands, resulting in areas of Minor (Yellow) HeatRisk east and
south of the Puget Sound.
Models have come into slightly better agreement heading into
next weekend, showing split flow developing aloft as a closed
low drops southward along the coast and the upper level ridge
progresses east of the Rockies. This will likely maintain mild
temperatures across the region, with ensembles maintaining a
slight chance of mountain showers next weekend.
15
&&
.AVIATION...North to northwesterly flow aloft continues through
Monday with troughing over the interior West and upper ridge
offshore. VFR conditions for the interior, with MVFR/IFR stratus
along the coast. Onshore flow tonight into Monday will result in
stratus spreading into the interior through this period.
Predominantly MVFR/IFR cigs for the interior sites late tonight
through Monday morning, with IFR along the coast. Cigs will slowly
improve into VFR midday Monday into early Monday afternoon for
interior locations, with MVFR continuing along the coast. Southerly
winds will increase tonight into Monday.
KSEA...VFR conditions into early tonight. Stratus will move into the
interior late tonight, with lower end MVFR cigs expected to develop
around 09-10z. MVFR cigs then remain through 18-19z before
improvements to VFR in the afternoon. There also remains
approximately a 30% probability of IFR cigs, peaking between 10 to
15z Monday. S/SW surface winds through the TAF period ranging
between 5 to 10 kts. JD
&&
.MARINE...
High pressure continues over the coastal waters, with lower pressure
to the east. The flow returns to onshore this week with weak pushes
through the Strait of Juan de Fuca. The strongest push in the
guidance is Monday evening, but the probability of winds exceeding
20 kt remains low. Low ceilings in the coastal waters Monday morning
(with pockets of fog) may lower visibilities at times to mariners.
The next potential system may bring breezy winds over the coastal
waters around Friday.
Seas for Sunday hold around 4-6 ft, and increase to 6-8 ft for the
remainder of the week. There is potential for 9-10 ft seas Thursday
and Friday depending on the track of the next system.
HPR
&&
.HYDROLOGY...
No river flooding is expected over the next 7 days.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...None.
&&
$$
NWS SEW Office Area Forecast Discussion