Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
324
FXUS66 KSEW 231622
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
922 AM PDT Thu Apr 23 2026
.SYNOPSIS...
Upper level ridge offshore nosing into Northern British
Columbia combined with upper level low well to the east giving
Western Washington northerly flow aloft through the weekend. Air
mass unstable enough for a chance of late day showers over the
mountains Sunday and Monday. The upper level ridge will move
over Western Washington in the middle of next week.
&&
.SHORT TERM /TODAY THROUGH SATURDAY/...
Radar imagery still showing some weak returns this morning,
resulting in some drizzle at some locations. Otherwise, no
major updates to the forecast this morning.
Upper level ridge building into Northern British Columbia today
while an upper level low remains well to the east. End result
northerly flow aloft over the area. The forecast problem of the
day is when the moisture over Western Washington will dissipate.
While the northerly flow aloft is dry the flow in the lower
levels remains weakly onshore this morning. Not getting any
upper level ridging to provide some subsidence to help out with
the clearing. The layer is about 2500 feet thick with tops
5000-6000 feet. The low level flow does turn northerly this
afternoon. This plus the late April sunshine will slowly erode
the moisture layer over Western Washington this afternoon into
the evening hours. Cloudy skies for the most part this morning.
Highs in the mid 50s to lower 60s.
Skies clearing tonight. Lows in the mid 30s to lower 40s.
Dry northerly flow aloft with northerly flow in the lower levels
will give Western Washington plenty of sunshine Friday and
Saturday. Highs in the upper 50s to mid 60s. It will be a cool
night Friday night/Saturday morning. The potential is there for
another frost advisory for the Southwest Interior with lows
near freezing. For the remainder of the area lows in the mid
and upper 30s. Felton
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Extended models in pretty good agreement with the upper level
low well to the east digging back to the west a little Sunday
and Monday pinching off the upper level ridge. North
northeasterly flow aloft still dry. Late day instablilty along
with weak upslope flow could produce a shower over the Cascades
in the late afternoon and evening hours both days. Upper level
low weakens and moves east Tuesday and Wednesday allowing the
upper level ridge offshore to move into the area. Low level flow
never turns offshore through the entire period. This will keep
highs mostly in the 60s with lower 70s possible as the ridge
axis moves overhead Wednesday. Lows upper 30s to mid 40s.
&&
.AVIATION...
Ceilings are slowly improving across the area early this morning,
with most locations now at low-end VFR, through areas of MVFR
persist across the northern interior terminals. Low-end VFR/MVFR
will likely persist through much of the day and into the early
afternoon in this area as weak low-level convergence continues to
persist. Clearing remains on track between 22Z Thu - 03Z Fri. Patchy
to local areas of fog may then begin to develop around/after 12Z Fri
in the valleys. Southerly winds around 5 to 10 kt will slowly ease
this morning, becoming mostly light westerly after 21Z, then
northwest to north after 00Z Mon.
KSEA...Ceilings have lifted to VFR and have begun to break apart
early this morning. Low-end VFR to upper-end MVFR cigs will continue
to persist over the terminal through around 00Z Fri when clouds will
begin to scatter. Best chances for additional lower cigs will be 15-
20Z this morning (25-35% chance MVFR cigs). South winds 8 to 12 kt
will decrease after 18Z as winds become more westerly around 21Z
then north after 00Z Mon. There will be a 15-20% of low stratus or
fog development after 12Z Mon.
62/HPR
&&
.MARINE...
The overall weather pattern looks to remain fairly static over the
next week. Broad high pressure over the northeast Pacific will
remain offshore and get pushed out as lower pressure remains in
place over the inland Pacific northwest. Winds may be a bit breezy,
mainly over the interior waters and the gaps in the coastal terrain,
on Friday as winds turn north to northeasterly. Lighter onshore flow
resumes Sunday into early next week. Seas currently 10 to 12 ft will
continue to ease this morning to below 10 ft by this afternoon, with
seas remaining 5 to 8 ft through the remainder of the forecast
period.
62
&&
.HYDROLOGY...
No river flooding the next 7 days.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 11 AM PDT this morning for Coastal
Waters From Cape Flattery To James Island 10 To 60 Nm-
Coastal Waters From Cape Flattery To James Island Out 10
Nm-Coastal Waters From James Island To Point Grenville 10
To 60 Nm-Coastal Waters From James Island To Point
Grenville Out 10 Nm-Coastal Waters From Point Grenville
To Cape Shoalwater 10 To 60 Nm-Coastal Waters From Point
Grenville To Cape Shoalwater Out 10 Nm-Grays Harbor Bar.
&&
$$
NWS SEW Office Area Forecast Discussion