Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
637
FXUS66 KSEW 010334
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
834 PM PDT Sat Oct 31 2026
.SYNOPSIS...Drier conditions will settle into the region into
Monday as an upper low moves south and a ridge builds into the
region. The first half of next week will remain mostly dry, with
chances of precipitation increasing mid to late week as a
series of systems approaches the Pacific Northwest.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...An upper level low
will continue to weaken as it moves onshore to the south, with
split flow briefly developing aloft over western Washington.
Cool overnight lows in the 30s will bring areas of additional
frost development to the area on Sunday morning while moisture
in the low levels promotes another round of morning fog. A Dense
Fog Advisory has been issued for portions of Puget Sound and the
Southwest Interior due to the expected fog development. Fog is
already beginning to develop in isolated river valleys, and is
expected to further expand tonight into Sunday morning.
High pressure building into the Pacific Northwest will maintain
dry conditions and seasonable temperatures through Monday, with
periods of morning fog and afternoon sun breaks. As the upper
level ridge axis shifts eastward on Monday, ensembles continue
to show low chances of rain generally along the coast and over
the Olympic Peninsula.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...Chances for light rain
continue into Tuesday as a splitting frontal system passes over
the region. Wetter and more unsettled conditions are expected to
return on Wednesday and beyond as a series of systems are set
to move over the region. While ensembles continue to show a fair
amount of variability heading into next weekend, the system
Friday looks to be the strongest and will likely bring breezy
winds alongside widespread lowland rain and mountain snow.
JD/15
&&
.AVIATION...Most locations across western Washington are VFR
this evening. Areas of localized fog have begun to form around
Olympia and the in the middle Chehalis river valley and will
continue to expand and encompass much of the western WA
lowlands. The highest confidence remains across the metro area
south of Everett, through will also expand, at least briefly,
towards HQM and BLI. This will bring widespread LIFR conditions
through Sunday morning. Improvement to VFR expected after
18-20Z. Northerly surface winds 4-6 kt becoming light and
variable tonight into Sunday morning.
KSEA...VFR conditions today. Conditions will deteriorate Sunday
morning with LIFR fog expected to form at the terminal after 10Z-
12Z, through latest satellite trends indicate the potential for an
earlier start. Conditions will improve to VFR after 18-20Z. NW winds
will ease this evening becoming 5 kt or less into Sunday morning.
29/62
&&
.MARINE...Shower activity was decreased this afternoon across
the coastal waters and the threat for brief waterspouts has
ended.
A surface low pressure will continue to dig south today. High
pressure will build over the waters tomorrow through Monday. A
system will approach the coastal waters to the north, leading to an
increase in winds over the outer coastal waters on Monday. Latest
guidance suggests there is a 55-70% chance for wind gusts briefly
exceeding 21 kt Monday morning over zones PZZ170 and PZZ173. High
pressure will move inland on Tuesday. The next system arrives
Wednesday. Winds will increase across the coastal waters; however,
latest probabilities indicate a 40-50% chance for wind gusts meeting
small craft thresholds. A stronger system will impact the waters
Thursday into Friday, bringing stronger winds across the coastal
waters and interior waters, with latest probabilities at 65-75% for
winds above 21 kt.
Seas 4-6 feet this afternoon, decreasing below 5 feet tonight. Seas
will build on Monday 7-10 feet and will hover around this range
through late in the week. With the stronger system arriving Friday,
latest guidance suggests seas will build up to 13-16 feet.
29
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Dense Fog Advisory from 1 AM to 10 AM PDT Sunday for City of
Seattle-Downtown Everett / Marysville Area-Eastern Kitsap
County-Eastside-Lowlands of Lewis and Southern Thurston
Counties-Lowlands of Pierce and Southern King Counties-
Olympia and Southern Puget Sound-Shoreline / Lynnwood /
South Everett Area.
Dense Fog Advisory until 10 AM PDT Sunday for Lower Chehalis
River Valley-Middle Chehalis River Valley.
PZ...None.
&&
$$
NWS SEW Office Area Forecast Discussion