Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
498
FXUS66 KSEW 301049
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
349 AM PDT Wed Sep 30 2026
.SYNOPSIS...
A frontal system will move out of Western Washington
into this evening. High pressure builds aloft over the Pacific
Northwest Thursday and Friday, with just a slight chance of
precipitation. The upper ridge further builds over the weekend
for drier, warmer conditions.
&&
.SHORT TERM /TODAY THROUGH FRIDAY/...
Drier conditions across Western Washington this morning as a few
lingering light showers continue to taper this morning. With the
abundant low-level moisture from yesterday`s rainfall and
decreasing winds, expect to see the spatial coverage of fog to
increase this morning toward daybreak. Low clouds gradually
decrease through the day with at least partial sunshine for the
afternoon. Not much change in the overall picture through
Thursday. With the flow remaining zonal, there`s the potential
for enough of an impact from the next disturbance clipping the
far north as it passes across southern B.C. This brings some
rain chances to the northern portions of the interior (mostly
Whatcom/Skagit counties), but even for the areas that see rain
it should remain quite light. As this disturbance exits the
region on Friday, a few light showers may linger in the North
Cascades, but dry conditions hold for most of the area.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Ensemble guidance remains in fairly strong agreement for the
weekend into early next week. the pattern would likely
favor a return of high pressure and some light offshore flow.
This could yield a somewhat mild start to October, with
temperatures into the lower to mid 70s Sunday. The return of
more onshore flow would return early next week as the high
pressure nudges slightly eastward, bringing temperatures back
down closer to 70 for daytime highs with the greater marine
influence. Overall, though, mild and dry conditions expected for
the long term period.
&&
.AVIATION...
Majority of terminals VFR this morning with either clear skies or
overcast skies. A few terminals with clear skies and light winds
have been reporting fog with visibility as low as 1/4SM,
particularly north of PAE. Fog still remains a possibility for
terminals along the Southern Interior and Kitsap Peninsula if
conditions remain clear with light winds. As for the other
terminals, low ceilings possible through the afternoon hours.
Guidance highlights the chance for MVFR cigs for Puget Sound after
12Z. Improvement expected in the afternoon to VFR after 18z-20z.
Light northerly to calm winds early this morning will increase in
the afternoon to 6-8 kt.
KSEA...VFR conditions early this morning. Guidance continues to
highlight the chance (50%) for MVFR cigs later this morning after
11Z. There is a slight chance (20%)for IFR cigs between 14-17Z.
Ceilings will lift in the afternoon after 19-20Z and VFR conditions
will prevail into the evening. Light NE winds early this morning 5
kt or less. Winds will shift NW in the afternoon and increase to 6-8
kt. Winds ease this evening, turning NE at 5 kt or less. 29
&&
.MARINE...
Seas subsiding over the coastal waters this week. Meanwhile,
building high pressure over the waters with a thermal low
pressure building north along the coast by the weekend. This
will induce northerly to weak offshore flow over the waters, but
speeds aren`t expected to be particularly strong. This will
maintain seas generally 3-6 ft over the coastal waters and
conditions short of advisory thresholds.
&&
.FIRE WEATHER...
Mostly dry conditions through the week ahead with additional
wetting rain not expected. A few light showers across the north
may develop with a passing disturbance late Thursday into
Friday. Otherwise, attention turns to a warmer period with
temperatures well into the 70s this weekend under stronger high
pressure. This may bring a brief switch to light offshore flow
as a thermal trough builds north over the region. This looks to
shift eastward for a return to onshore flow and closer to normal
conditions early next week.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...None.
&&
$$
NWS SEW Office Area Forecast Discussion