Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
261
FXUS66 KSEW 130346
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
846 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/...
Short-lived isolated thunderstorms have been firing up this
evening along the Olympic Peninsula and Puget Sound. Latest
radar observations show a batch of thunderstorms moving north
from Oregon towards Western Washington. If they manage to
hold themselves together, expect the storms to move across
Puget Sound in the next 30 minutes to hour. Isolated
thunderstorms remain possible through tonight across the region.
29
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...
Southwesterly flow aloft will persist through the TAF period as
an upper level trough approaches the region. Showers and some
isolated thunderstorms have started to pop up along the Olympic
Peninsula over the past few hours and latest radar shows a new
batch of showers and thunderstorms moving up into the region
from the south. While current conditions remain VFR across the
area this evening, conditions could quickly drop down to MVFR or
even IFR in any heavier shower or isolated thunderstorm activity
as showers continue to move up into the area. At this time,
confidence remains too low for inclusion of thunder in any
single TAF site, however conditions will continue to be
monitored and updated through the evening hours.
Winds are southwesterly this evening, generally persisting
between 7-12 kt, though could get gusty to 20-25 kt in the
vicinity of shower activity. Expect ceilings to lower to more
widespread MVFR overnight as showers fill in across the region.
Showers will taper through the afternoon hours on Wednesday,
except for a convergence zone that looks likely to develop
across the central Sound Wednesday afternoon into evening. Winds
will remain out of the southwest into Wednesday, with a couple
spots becoming breezy later in the day.
KSEA...VFR conditions, with southwesterly winds persisting
between 7-12 kt. Gusts to 20-25 kt will be possible through
evening, especially in any stronger shower activity. Isolated
thunderstorms may approach the terminal tonight into the overnight
period, though confidence is too low for inclusion in the TAF at
this time. Isolated thunderstorms may move into the vicinity of the
terminal as early as 04-05Z. Ceilings will lower to MVFR overnight
as general shower activity increases. Showers will decrease through
the afternoon on Wednesday. A PSCZ looks to develop Wednesday
afternoon and persist into Wednesday evening, but looks to largely
stay to the north of the terminal at this time.
&&
.MARINE...
Showers and isolated thunderstorms moving into the area may
briefly reduce visibilities across portions of the interior
waters tonight. Winds have also increased a bit over the
waters, especially through the Strait of Juan de Fuca. Small
craft advisory winds will persist 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/14
&&
.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 until 5 AM PDT Wednesday for Central U.S.
Waters Strait Of Juan De Fuca.
&&
$$
NWS SEW Office Area Forecast Discussion