Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
253
FXUS66 KSEW 080312
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
812 PM PDT Tue Apr 7 2026
.SYNOPSIS...
Dry conditions will persist across western Washington through
Friday, with a gradual warming trend expected over the next few
days. Clearing skies and cool overnight temperatures will allow
for frost formation across the portions of western Washington
both Wednesday and Thursday mornings. Cooler temperatures and
rain chances return by the weekend as the next system approaches
the Pacific Northwest.
&&
.SHORT TERM /TODAY THROUGH THURSDAY NIGHT/...
Quiet conditions prevail across Western Washington this evening with
weak ridging in place at the surface and aloft. Mostly clear skies
overnight will allow temperatures to dip to around freezing across
the Southwest Interior where a frost advisory remains in effect.
Western Washington will be sandwiched in the midst of split flow
aloft on Wednesday as a cutoff upper level low approaches northern
California and a shortwave trough dives southward across interior
British Columbia. The end result will be a pleasant spring day
locally with temperatures a smidge above average under plentiful
sunshine. The warming trend continues into Friday before a deeper
cutoff low moving into the West spreads a few showers and cooler
temperatures our direction for the weekend. Though it looks to be
far from a washout. All in all, we`ve got a few pleasant days ahead
to enjoy everything in bloom. Previous discussion follows. 27
Cooler conditions persist across the region this afternoon, with
temperatures generally trending in the low 50s across the area-
and roughly 10 to 20 degrees below where they were at yesterday
at around 2PM/21Z. Satellite imagery shows lingering cloud
cover scattering out across the central Sound this afternoon,
with most areas seeing some sun.
Weak high pressure building into western Washington will keep
conditions dry through the second half of the work week and
will allow for afternoon highs to climb a few degrees each day.
Clearing skies will also allow for chilly conditions to develop
overnight, with low temperatures expected to drop into the low
to mid 30s across portions of the south Sound and Chehalis River
Valley. This will promote the development of frost across these
areas both Wednesday and Thursday mornings.
Afternoon highs on Wednesday will primarily be in the mid 50s
to mid 60s across the region and will climb into the 60s area-
wide by Thursday. A few spots across the Chehalis River Valley
and Cascade valleys could even approach 70. This will re-introduce
Minor HeatRisk to areas across the interior on Thursday, generally
from the central Sound southward.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
Conditions will remain dry on Friday as western Washington
remains situated under high pressure. Afternoon highs will peak
across the interior, with temperatures expected to approach the
upper 60s to low 70s for the Cascade valleys and areas from the
central Sound southward. One last day of Minor HeatRisk is expected
for portions of the interior on Friday, before a pattern change
commences over the weekend.
Cooler temperatures and rain chances return on Saturday as an
upper level low drops southward into the region from the Gulf of
Alaska. While there is still some uncertainty in regards to the
track of this system, ensembles do highlight the switch to a
cooler and more unsettled period for the region over the weekend
and heading into early next week. At this time, afternoon
temperatures over the weekend look to cool 10 to 15 degrees
from Friday`s peak and look to top out in the low to mid 50s.
14
&&
.AVIATION...
Northwesterly flow aloft continues over western Washington tonight
into Wednesday. VFR conditions are expected to prevail through the
TAF period with mostly clear skies and periods of high cirrus at
times. High-res guidance continues to hint at potential for some
patchy low clouds and fog through portions of the Southwest
Interior, mainly affecting OLM and HQM, with around a 15-20% chance
of LIFR conditions at OLM from around 11-17Z. Winds already light
and variable should become mostly calm overnight. Winds increase
after 18Z Wed becoming N/NW 5 to 10 kt through the day.
KSEA...VFR conditions and north winds prevail through the TAF
period. NW winds 5 kt or less will transition to more NE after
around 06Z Wed, becoming light and variable at times. Winds increase
16-18Z to NW 8 to 10 kt during the day Wednesday.
62
&&
.MARINE...
Winds and seas (though relatively steep, 6-7 ft at 8 s) will slowly
ease this evening and remain relatively light through the rest of
the work week as high pressure remains in place over the northeast
Pacific. A low pressure system looks to arrive over area waters this
weekend before exiting early next week. No impacts are currently
associated with it. High pressure is favored to rebuild into early
next week. Seas remain 4-6 ft through the week.
41/62
&&
.HYDROLOGY...
No river flooding expected in the next 7 days.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Frost Advisory from 11 PM this evening to 9 AM PDT Wednesday
for Foothills and Valleys of Thurston and Lewis Counties-
Lowlands of Lewis and Southern Thurston Counties-Middle
Chehalis River Valley-Olympia and Southern Puget Sound-
Willapa and Black Hills.
PZ...None
&&
$$
NWS SEW Office Area Forecast Discussion