Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
643
FXUS66 KSEW 222127
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
227 PM PDT Tue Sep 22 2026
.SYNOPSIS...
Onshore flow will maintain cooler temperatures and cloudy skies
through Thursday, with some drizzle tonight into Wednesday. A
stronger system will bring showers across western Washington
Thursday morning, with more widespread rain later Tuesday into
Friday morning. Cooler and unsettled conditions will continue
through the weekend, with additional chances for precipitation
into next week.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
Broad upper level troughing will maintain southwest flow aloft
and onshore flow at the surface over the next few days, with
little change between today and tomorrow. Most of the low
stratus from this morning has eroded under partly cloudy skies,
with highs on track to peak in the mid to upper 60s for most
areas. A weak disturbance in the upper level flow will bring
increased clouds and some sprinkles alongside another marine
push. This will bring low clouds and light showers inland
tonight into early Wednesday morning. Conditions will improve by
the afternoon, with cloudy skies lingering and highs once again
generally in the mid to upper 60s.
A warm front will lift northward across the region Thursday
morning, bringing light showers to the region. Forecast models
show some differences in the timing, but a cold front will
follow, bringing in widespread precipitation by the evening.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
Widespread precipitation will move inland through Friday
morning, with most lowland areas seeing roughly half an inch of
rainfall and amounts closer to an inch over the mountains. With
snow levels dropping to 6000-7000 feet on Friday, some of the
higher peaks will even see the first dusting of snow of the
season. Showers will likely continue throughout the day Friday
as the upper level trough axis shifts east of the Cascades.
Forecast models continue to hone in on weak ridging building in
behind on Saturday, which will temporarily bring drier
conditions to western Washington. However, ensembles maintain
chances across the region for more precipitation on Sunday and
into early next week, with cooler-than-normal temperatures
staying in place. Some uncertainty remains in model solutions
early next week, with some breaking apart a frontal system as it
reaches the coast. Regardless, additional rainfall is on the
way, with more fall-like weather settling into place.
15
&&
.AVIATION...
Conditions continue to improve towards VFR this afternoon as
cloud cover continues to scatter across western WA. A weak
frontal system moving into western WA late tonight into early
Wednesday will bring another round of lowering ceilings to the
area by Wednesday morning. Most guidance suggests ceilings will
range between low-end VFR to MVFR, though cannot rule out some
localized IFR conditions developing. Light showers will be
possible as this system moves into the area, most likely for
terminals along the coast (KHQM) and Strait (KCLM). KBLI and
KOLM may also see some light shower activity, but overall expect
much of the interior terminals to remain dry as the front breaks
up as it moves inland. Southwesterly winds between 5-10 kt will
persist for the majority of the terminals through this evening
before winds ease and become light overnight.
KSEA...VFR conditions are expected to prevail. Ceilings will lower
again on Wednesday morning as a front approaches the terminal,
however guidance continues to keep conditions VFR with the
lowest ceilings remaining around 4000 ft. South to southwest
winds will persist at 5-10 kt into Wednesday.
14
&&
.MARINE...
A weak front will move across the area late tonight into
Wednesday with little to no impact expected across the area
waters. Onshore flow will continue with another, weaker push of
westerly winds expected along the Strait of Juan de Fuca this
afternoon and evening. At this time, wind gusts largely look to
remain below 20 kt for the majority of the Strait.
A stronger frontal system will then move through the area waters
Thursday into Friday, bringing an increased likelihood of small
craft winds to the coastal waters and along the Strait of Juan
de Fuca. A third system may approach the waters over the weekend,
but latest guidance shows the system breaking up as it approaches,
so do not expect much in the way of hazardous winds or seas at
this time.
Seas will primarily persist between 5-8 ft through Thursday
before building towards 9-10 ft on Friday in the wake of frontal
system. Seas will then subside towards 4-6 ft over the weekend.
14
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...None.
&&
$$
NWS SEW Office Area Forecast Discussion