259
FXUS66 KSEW 281528
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
828 AM PDT Fri Jun 28 2024

.UPDATE...Zonal flow aloft with weak onshore flow at the surface
will maintain cloudy skies across western Washington today as
temperatures return to near normal. Prolonged radiation will allow
for some breaks in cloud cover heading into the afternoon ahead of
another influx of moisture with an approaching weak front that
will move inland on Saturday. The forecast remains on track, with
no updates this morning.

&&

.SYNOPSIS...Zonal flow aloft over Western Washington today with
light onshore flow in the lower levels. Weakening front moving by
to the north Saturday. Upper level trough over the area Sunday
keeping a chance of showers in the forecast. Upper level ridge
building offshore Monday moving into the Pacific Northwest Tuesday
through Thursday. Low level flow remaining onshore keeping
temperatures near normal.

&&

.SHORT TERM /TODAY THROUGH SUNDAY/...Satellite imagery shows
cloudy skies over most of western Washington this morning. No
precipitation echoes on the doppler radar at 8am/15z.
Temperatures with the cloud cover pretty uniform, in the lower to
mid 50s. The exception is around Olympia where a little bit of
clearing has allowed temperatures to drop into the mid 40s.

No much going on today weatherwise. Zonal flow aloft combined with
light onshore flow in the lower levels will keep at least mostly
cloudy skies over the area. With the near solstice daytime
heating working on the low level moisture some sunshine will
develop in the afternoon. Highs near normal with mid 60s along the
coast and upper 60s to mid 70s inland.

Weakening front near 140W early this morning will approach the
coast early Saturday morning. Parent low associated with the front
up in the Gulf of Alaska and moving northwest. This will stretch
out and weaken the front today and tonight. Front close enough for
a chance of showers along the North Coast with just mostly cloudy
skies over the remainder of the area. Lows tonight in the upper
40s to mid 50s.

What is left of the front dragging through Western Washington
Saturday. Best chance for showers will be along the coast, in the
mountains and over the Northwest Interior. Any showers that do
develop will be light. Highs similar to today with mid 60s coast
and upper 60s to mid 70s inland.

Weak upper level trough remaining over Western Washington Saturday
night into Sunday. Not a whole lot with this feature with 500 mb
heights in the lower 570 dms. There will be plenty of low level
moisture so any lift could produce a light shower or perhaps some
morning drizzle. Once again best chances will be along the coast,
in the mountains and over the Northwest Interior. Lows Saturday
night in the upper 40s to mid 50s. Little change in the high
temperatures from the previous two days with mid 60s along the
coast and upper 60s to mid 70s inland.

.LONG TERM /MONDAY THROUGH THURSDAY/...Extended models in good
agreement with an upper level ridge building offshore Monday. The
ridge will weaken slightly as it moves over the Pacific Northwest
Tuesday with the ridge remaining over the area into the 4th of
July. A weak shortwave riding down the backside of the ridge
Monday morning could trigger a shower in the North and Central
Cascades. 500 mb heights rising to the upper 570 dms to the mid
580 dms by the middle of the week but the low level low remains
onshore. This will keep highs in the mid to upper 60s on the coast
and upper 60s to mid 70s inland Monday and Tuesday. A little
warmer Wednesday and on the 4th with highs in the mid 60s to lower
70s along the coast and 70s to lower 80s inland. Felton

&&

.AVIATION...Northwesterly flow turning westerly this afternoon as
weak transient ridging builds over W WA. Mix of MVFR/VFR CIGs
continue with some of the terminals already beginning to lift into
VFR. Most of the MVFR remains west of Puget Sound, and east into the
Cascades (with possible IFR obstructing mountains, particularly
around KSMP). Ceilings are expected to improve into the early
afternoon to widespread VFR for the region, with VFR persisting
throughout the remainder of the day. Winds will become northwesterly
at 4 to 8 kt.

KSEA...CIGs have improved to VFR and will scatter out by the
afternoon. Northeasterly winds around 4 to 8 knots will turn N/NW
later this morning and will hover around 6 to 9 knots.

Maz/HPR

&&

.MARINE...Weak high pressure offshore will bring generally benign
and calm conditions to the area waters today. Additional weak
systems look to move through the area waters through the weekend,
along with diurnal pushes down the Strait of Juan De Fuca also likely
through early next week. At this time, winds look to be below any
criteria until possibly Monday night.

Coastal seas 4 to 6 feet through the weekend and into early next
week, before building to 6 to 8 feet by the middle of next week.

Maz

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...None.
&&

$$