754
FXUS66 KSEW 282202
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
302 PM PDT Fri Jun 28 2024

.SYNOPSIS...A weak shortwave will bring in increased cloud cover
and light showers this evening. Another frontal system will cross
western Washington on Saturday, bringing in another round of
showers. Unsettled and cloudy weather will linger into Monday
morning before high pressure offshore allows conditions to dry out
and slowly warm up through the end of next week.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY/...Skies have cleared
throughout the morning and early afternoon, allowing for temps to
make a run at 70 degrees. Clearing will last a few more hours
before onshore flow leads to increased cloud cover and slight shower
chances this evening and tonight. Any showers will be light and
focused on the peninsula and North Cascades, resulting in little
to no accumulation.

A front will swing through the region throughout the day Saturday,
with additional light shower chances confined mainly to the
Olympics and higher terrain in the North Cascades. While much of
the lowlands will see little more than cloudy skies and some
occasional sprinkles, the mountains will see light accumulations
of a few hundredths. Temperatures will return to near normal for
late June with highs in the mid 70s across the lowlands.

Shower chances will taper off Sunday, leading us into a drier
upcoming period with a ridge building offshore. High resolution
models continue to hint at the possibility of convergence zone
shower activity developing along the King/Snohomish County line,
though the exact track and intensity of any convergence zone
showers is uncertain. Cloudy skies with periodic breaks will
persist for much of the region on Sunday as onshore flow
continues.

Northwest flow aloft will maintain somewhat cloudy skies on
Monday, with a slight chance for showers lingering over the
mountains. Otherwise, Monday will be the last day of spring-like
weather ahead of a pattern change on tap for the rest of the
week.

.LONG TERM /TUESDAY THROUGH FRIDAY/...Models in good agreement
with a warming, drying trend throughout next week as an upper
level ridge shifts onshore Monday into Tuesday. A weak shortwave
will influence the region Tuesday night into early Wednesday
morning, with shower chances minimal and temperatures increasing
several degrees above normal. The ridge axis will cross over the
region on Thursday with high pressure dominating the weather
pattern into next weekend. The warmest days will likely come late
in the extended period as we`ll see a 50-60% chance of exceeding
80 degrees for the lowlands going into next weekend.

Shepard/Lindeman

&&

.AVIATION...West flow aloft will become more southwesterly ahead of
a shortwave trough approaching from the Pacific Saturday night into
Sunday. CIGs are beginning to scatter out - mostly VFR across the
terminals (few holdouts in MVFR off the coast and around KPAE but
will scatter out throughout the afternoon). Overnight the ceilings
will fill back in, but will stay VFR (except for the Cascades and
along the coast with MVFR - IFR/LIFR possible in the Cascades). A
few showers will be possible with a weak front Saturday afternoon,
especially along the coast and in the mountains. West and northwest
winds 6 to 10 kt will weaken overnight and become light and variable
Saturday morning, before blowing westerly.

KSEA...VFR CIGs will continue to scatter out this afternoon. A mid
level VFR ceiling will fill in ahead of the front. Showers are
expected to stay north/west of the terminal. Light north winds 6 to
10 kt will weaken overnight, and become more westerly during the day
Saturday.

HPR

&&

.MARINE...High pressure will build offshore today with weak
onshore/northerly flow over the waters. A weak system will pass
through the region this weekend. No hazards are expected with this
push through, as winds become light and more westerly Saturday and
Sunday with the frontal passage. Behind the system, pushes down the
Strait of Juan de Fuca will be almost daily. The strongest of the
pushes will be Sunday and Monday afternoon, but are expected to
remain below 20 kt. Seas of 3 to 4 feet today/Saturday will build to
4 to 6 feet Sunday through Tuesday, increasing to 6 to 8 feet
Wednesday and Thursday.

HPR

&&

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

$$