046
FXUS66 KSEW 261037
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
337 AM PDT Sun May 26 2024

.SYNOPSIS...Cooler and showery conditions will continue across
western Washington today as a frontal system brushes the region.
Upper level ridging will then gradually begin to build east of
the area Monday, allowing for temperatures to warm a few degrees.
Upper level troughing over the northeastern Pacific will continue
to influence Washington, however, with the next frontal system
slated to move across the region on Tuesday. Drier and warmer
conditions will be possible late in the week as upper ridging
builds offshore.

&&

.SHORT TERM /TODAY THROUGH TUESDAY/...A weak frontal system will
brush the region today, bringing showers and cooler temperatures
to much of western Washington. Radar shows a few light showers
persisting across the central and northern Cascades this morning,
but also shows shower activity increasing offshore and moving
inland along the North Coast. Expect showers to continue to
progress inland through the day today, with overall precipitation
amounts remaining rather light for the majority of the interior
lowlands. The bulk of precipitation will likely remain along the
North Coast, the mountains, and areas generally north of Snohomish
county. Showers then look to taper tonight across the majority of
the area, with a few persisting along the Pacific coast into
Monday. High temperatures will be roughly 5 to 10 degrees below
normal, and look to only climb into the mid to upper 50s.

An upper level ridge will start to build east of the area on
Monday, while troughing offshore continues to influence western
Washington. Overall, expect drier conditions for the majority of
the forecast area, with only a few showers persisting along the
coast. Temperatures will warm closer to normal, with afternoon
highs climbing into the mid 60s to near 70 across the interior.
The coast will remain cooler, with high temperatures topping out
in the low 60s.

The next upper level disturbance and associated surface frontal
system will then move across the region on Tuesday, bringing
another round of showers and cooler temperatures. Showers will
move along the coast early Tuesday and gradually make their way
into the interior by the afternoon hours. Afternoon high
temperatures will fall back to 5 to 10 degrees below normal,
topping out in the upper 50s to low 60s for most areas.

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...An upper level trough
over the northeastern Pacific will push its trough axis onshore on
Wednesday. This will maintain chances of showers and below normal
temperatures across western Washington midweek. Shower coverage
then looks to gradually decrease on Thursday as the trough axis
pushes further off to the east and upper level ridging starts to
build over the northeastern Pacific. Ensemble guidance remains in
in decent agreement in regards to the upper ridge influencing
western Washington late in the week, which would mean warmer and
drier conditions Friday and heading into next weekend. 14

&&

.AVIATION...Westerly flow aloft with a warm front lifting across the
region this morning. This will maintain a rather moist air mass and
consistent southerly or southwest low-level flow across much of the
region with onshore flow through the Strait of Juan de Fuca. Expect
widespread MVFR and local IFR ceilings early this morning with light
rain showers. Ceilings will be slow to lift, but expect widespread
MVFR late morning giving way to VFR after 22z with the front pushing
northward into B.C. by late afternoon. Stabilizing air mass likely
brings return of low ceilings again Sunday night through Wednesday
morning.

KSEA...MVFR ceilings continue this morning with around a 15% chance
of dipping to IFR for a few hours 12-16z this morning. Light rain
showers at times through the morning. Southerly surface wind around
10 kt with some gusts toward 20 kt this afternoon as front lifts
north. MVFR ceilings likely return again after 03z through much of
overnight period. Cullen

&&

.MARINE...A passing warm front lifts north across the waters into
southern B.C. later today, but winds likely remain below advisory
thresholds across all waters for the next few days. Another front
reaches the waters on Tuesday with a stronger west push down the
Strait of Juan de Fuca Tuesday night may bring winds again into the
20-25 kt range, with around a 40% chance of reaching advisory
speeds. Seas over the coastal waters remain dominated by rather
short period waves, which will maintain choppy conditions through
much of the week ahead, with seas generally holding in the 5 to 7 ft
range. Cullen

&&

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

$$