Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
983
FXUS66 KSEW 011606
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
906 AM PDT Fri May 1 2026
.SYNOPSIS...
Weak upper level low offshore through tonight with light flow in
the lower levels. Low moves south Saturday and Saturday night.
Upper level ridge building into coastal British Columbia over
the weekend with the low level flow turning offshore Sunday.
Record highs likely Sunday. Ridge moving over Western
Washington next week. Above normal temperatures will continue
but a switch to onshore flow in the lower levels will cool
things down beginning Monday for the coast and Tuesday for the
interior.
&&
.SHORT TERM /TODAY THROUGH SUNDAY/...
No significant changes made to the forecast this morning. The
previous discussion can be found below with updates to the
aviation section:
Satellite imagery shows weak upper level low
offshore. High clouds spinning out of the low moving over the
area early this morning.
Upper level low remaining offshore today throwing mostly high
clouds at Western Washington. Light flow in the lower levels so
while more stratus will form before sunrise it will stay west of
Puget Sound. The stratus will dissipate later this morning.
Under partly sunny skies temperatures will be above normal, in
the mid 60s to lower 70s except along the coast and near the
Strait of Juan de Fuca where highs will be in the lower 60s.
Little change in the upper pattern tonight with the low
remaining off the coast. High clouds spinning out of the low
will continue to move through Western Washington. Increasing
onshore flow in the lower levels with stratus forming along the
coast spreading inland early Saturday morning. Lows in the 40s.
Upper level low moving south Saturday with high clouds
decreasing over the area. Onshore gradients weakening with
stratus dissipating by noon leaving mostly sunny skies for the
afternoon. Highs over the interior remaining in the mid 60s to
mid 70s. Decreasing onshore flow will allow the coast to warm
into the mid 60s to lower 70s.
Low well to the south Saturday night and Sunday. Upper level
ridge building into the British Columbia coastline. Temperatures
aloft warming with 850 mb temps in the plus 14 to 16C range by
Sunday afternoon. Low level flow turning offshore Saturday night
and remaining offshore Sunday. Much warmer all locations with
highs in the 70s to mid 80s. Good chance for record highs.
Forecast high for Seattle of 81 degrees ( 16C at 850 mb is 61F
then add 20F ) would break the current record of 77 degrees.
Sunday will be the warmest day of the year so far.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...Models in good
agreement with the low level flow turning onshore Sunday night
into Monday. This will cool the coast down on Monday with a
little cooling as far east as Shelton. For the remainder of the
interior light flow in the lower levels as the flow transitions
to onshore. Temperatures aloft not cooling with 850 mb
temperatures still in the plus 14 to 16C range. Marine air will
have a tough time getting inland under these conditions making
Monday highs similar to Sunday from the Puget Sound eastward.
Low level onshore flow combined with cooling temperatures aloft
resulting in a weak marine push Tuesday with highs in the
interior 5 to 10 degrees cooler than Monday.
Upper level ridge over the top of the area Tuesday through
Thursday. Low level flow remaining onshore which will put a cap
on how warm it can get. Temperatures still above normal over
the interior, mid 60s to mid 70s. With a deeper marine layer
highs on the coast in the lower 60s.
We have been getting calls in the office asking how dry was
April. In Seattle the monthly rain total was 2.77 inches just
0.41 inches below the normal of 3.18 inches. Why it might have
seemed like a dry April is because of the number of days it
rained. In Seattle there was only 8 days with measurable rain.
This ties for the third lowest number of April rain days in
Seattle in the 82 years of records at Seattle-Tacoma airport.
The two years with less rain days, 1956 with 5 and 1951 with 3.
There have been 4 years with 8 rain days, 2026, 2021, 2020 and
1998. The normal number of rain days in Seattle in April is 15.
Since the start of the year there has been 55 days with
measurable rain in Seattle. This is the lowest January through
April rain day total since 50 days in 2005. The normal number of
rain days for January through April is 67. Felton
&&
.AVIATION...
A trough will dig offshore today for southwesterly flow today then
northeasterly flow this evening. Marine stratus should slowly erode
away this morning along the coast and the Strait of Juan de Fuca.
Elsewhere, VFR conditions will prevail through the TAF period with
high clouds streaming overhead. Another westerly push will bring
stratus clouds slightly farther inland Saturday morning but should
remain west of the Puget Sound terminals. Winds N/NW 5 to 10 kt
today will become light NE overnight.
KSEA...VFR today with high clouds. Winds N/NE 5 to 10 kt becoming NW
this afternoon. Light NE winds return overnight.
33/62
&&
.MARINE...
Onshore flow continues with high pressure offshore and
lower pressure inland. Outer Coastal Waters will see Small Craft
Advisory conditions with both NW winds and choppy seas. Expect
another push of westerlies down the strait tonight. The flow
turns more N to NE on Saturday with gusty 10-20 kt winds over
Puget Sound and Hood Canal. Offshore flow lingers into Sunday
then a stronger onshore push Monday night. 33
&&
.HYDROLOGY...
No river flooding in the next 7 days.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 11 PM PDT this evening for Central
U.S. Waters Strait Of Juan De Fuca-Coastal Waters From
James Island To Point Grenville 10 To 60 Nm-Coastal
Waters From Point Grenville To Cape Shoalwater 10 To 60
Nm-East Entrance U.S. Waters Strait Of Juan De Fuca.
&&
$$
NWS SEW Office Area Forecast Discussion