FXUS66 KSEW 060355
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
855 PM PDT Mon May 5 2025

.SYNOPSIS...
High pressure will lead to dry and warming conditions through
Tuesday. A weak system will arrive by Wednesday bringing cooler
temperatures and chances for showers. Somewhat warmer and
generally dry conditions return late week before another front
approaches the region over the weekend.

&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
Forecast remains on track this evening with just a few mid level
clouds and otherwise a clear night for most. High pressure will
remain in place into Tuesday, maintaining a warming trend for t
with highs peaking into the mid 70s to around 80 across much of
the region.

By Tuesday night into Wednesday, the next trough will move into
the region, ushering in cooler onshore flow and widespread but
brief chances for showers. Any precipitation will wane Wednesday
night.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
Thursday into early Saturday will see a general transition from
troughing to weak ridging across the area. This will allow
conditions to dry and warm slightly, though no where near as
warm as Tuesday. By later Saturday, confidence begins to
diminish as an upper level trough approaches the region. At some
point in the late Saturday-Sunday time frame this trough will
spread precipitation east across the western Washington.
Compared to yesterday, cluster analysis shows slightly better
agreement in limited instability Sunday. That said, there is
some indication that the trough could hang on a bit longer into
early next week, keeping chances for showers going.
-Wolcott-

&&

.AVIATION...
North/northwesterly flow aloft as high pressure builds over
Western Washington. Currently VFR conditions across all
terminals and expected to persist through the remainder of the
TAF period. Northerly (westerly along the coast) surface winds
are beginning to east this evening Winds will continue to ease
overnight to 3 to 5 kt and shift northeasterly.
North/northwesterly winds resume during the day Tuesday.

KSEA...VFR conditions expected to persist through the remainder of
the TAF period. N winds 5 to 10 kt easing to around 3 to 5 kt
tonight and becoming more northeasterly. North/northwest winds
resume again Tuesday.

29/62

&&

.MARINE...
Surface high pressure building over the coastal waters will
bring benign marine conditions through Tuesday. A weak frontal
system will traverse the waters on Wednesday. Surface winds over
the coastal waters will remain below 21 kt, however, a westerly
push across the Strait of Juan de Fuca will lead to sustained
winds speeds into the 21 to 30 kt range, with the strongest
winds along the Central Strait. High pressure will rebuild over
the region Thursday into Saturday, bringing calmer conditions
over the waters.

Seas generally between 5 to 6 ft will through Tuesday, and will rise
to 7 to 8 ft on Wednesday. Conditions will ease on Thursday, with
seas returning back to 5 to 6 ft through the weekend.

29

&&

.HYDROLOGY...
The daily hydrology discussion has ended until the start of the
next rainy season; it will only be updated if needed.

&&

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

&&

$$