Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
432
FXUS66 KSEW 122144
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
244 PM PDT Tue May 12 2026
.SYNOPSIS...
A lingering ridge of high pressure will bring one more day of warm
temperatures to western Washington today with the potential for
an isolated thunderstorm or two. A transition to onshore flow
and cooler conditions will take place on Wednesday along with a
chance of some precipitation. Cooler and unsettled conditions
will continue into the weekend as a trough of low pressure over
the Northeast Pacific sends a series of weak frontal systems
across the area.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
Lingering upper level ridge has continued to bring warm
conditions across the area this afternoon, with high
temperatures in the mid to upper 70s, along with some locations
in the Cascade foothills in the lower 80s. The ridge will shift
eastward tonight with an incoming trough offshore. With
southerly flow aloft and associated moisture with this incoming
trough, we could see an isolated thunderstorm or two,
particularly over the Southern portion of the Cascades this
evening as orographics give the instability a boost (20-30%
chance) The main hazard associated with any thunderstorm is
frequent lightning, brief erratic winds, and heavy downpours.
Again, could see an isolated thunderstorm or two move towards
the interior, but confidence is low at the moment. Otherwise, we
will see some scattered showers develop and move northward
later tonight and through Wednesday morning and fill in through
the interior.
We`ll see the upper level low track over the area on Wednesday,
keeping showers and unsettled weather in the forecast with
significantly cooler temperatures. High temperatures on
Wednesday will be in the upper 50s and lower 60s - almost a 15
degree temperature difference from the day before.
A shortwave will cross over the area on Thursday with a slight
warm up with temps in the lower 60s, with shower chances being
mainly confined to the Cascades. Will likely be a dry day for
the interior locations.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
A series of troughs look to cross over western Washington over
the weekend and into early next week. A trough on Friday will
help favor some instability over the area once again, resulting
in a slight chance of thunderstorms mainly over the North
Cascades. Cooler temperatures in the upper 50s to lower 60s look
to stay around for much of the weekend, with chances of
precipitation in the forecast through at least Monday.
Conditions look to dry out by Tuesday with temps warming into
the mid/upper 60s.
Mazurkiewicz
&&
.AVIATION...
High pressure across the region today with VFR conditions area-
wide. Increasing southwest flow aloft later today. Winds become
southerly this afternoon and increase a bit, with some gusts to
15-20 kt possible late this afternoon. There is a 60-80% chance
of showers passing through the terminals east of Puget
Sound/Cascades starting this afternoon through the overnight period.
There is also a 20% chance of thunder in the Cascades, generally from
Mt. Rainier southward. Expect mostly MVFR ceilings overnight. Winds
to remain out of the southwest Wednesday, with a couple spots
becoming breezy later in the day.
KSEA...VFR during the day, becoming southerly this afternoon.
Speeds increase to 8-12 kt later afternoon with gusts to 20 kt
through evening. Showers likely arrive after 06z Wednesday through
the terminal area, decreasing through the day Wednesday.
&&
.MARINE...
High pressure over the waters today, with the next system
approaching. Winds increase a bit over the waters, especially
through the Strait of Juan de Fuca. Small craft advisory winds are
likely (70-80%) in the central Strait zone this evening and tonight.
A more widespread round of onshore winds increases tomorrow through
the day, bringing higher end advisory winds to 30 kt through the
Strait. There remains lower (20-30%) chance of isolated gale gusts
in the central Strait tomorrow, but confidence isn`t high in this.
Otherwise, seas building over the coastal waters with a mix of a
longer period and shorter period wave groups will bring confused
seas that may be more hazardous than the wave heights (5-7 ft)
would otherwise suggest. Otherwise, onshore flow continues
through the Strait of Juan de Fuca later this week with
northerly winds over the coastal waters. Another round of
building seas to 8-9 ft over the coastal waters around Saturday
from a distant disturbance.
Cullen
&&
.HYDROLOGY...
The daily hydrology discussion has ended until the
start of the next rainy season; it will only be updated during
this time as needed.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory from 6 PM this evening to 5 AM PDT
Wednesday for Central U.S. Waters Strait Of Juan De Fuca.
&&
$$
NWS SEW Office Area Forecast Discussion