032
FXUS66 KSEW 192307
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
407 PM PDT Wed Jun 19 2024

.SYNOPSIS...High pressure continues to build over the region this
week, maintaining much warmer and continued dry conditions for
most of area. A few isolated thunderstorms are possible in the
North Cascades near the crest this afternoon. The ridge will break
down late this week, bringing a return to a cooler and wetter
pattern across the region for the weekend.

&&

.SHORT TERM /TONIGHT THROUGH SATURDAY/...Mostly clear skies across
the area this afternoon with temperatures climbing into the 70s
through most of the interior (cooler closer to the water). Some
patches of stratus remain over the coastal waters and a few areas
of cumulus build-ups in the Cascades, and will continue to monitor
the North Cascades in particular for the development of a few
isolated thunderstorms near the Cascade crest. The best chances
this afternoon will remain to the east of the crest.

High pressure will strengthen and an offshore flow pattern will
develop Thursday, which will warm temperatures another 5-10
degrees tomorrow afternoon compared to today`s highs. Friday will
be similar across the interior, with some cooling at the coast as
onshore flow resumes during the day. This cooler marine air will
begin to seep into the interior, but temperatures east of Puget
Sound likely remain well above normal for one more day on
Saturday.

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...The pattern shifts more
significantly into Sunday as more significant onshore flow returns
as the ridge shifts eastward. Ensemble guidance suggests this next
upper trough will take up position over the region and allow a
series of frontal systems to spread through the region. This will
bring temperatures back closer to seasonal normals and maintain at
least some rain chances. These rain chances will be most prominent
along the coast and in the Cascades.

&&

.AVIATION...Light northwesterly flow aloft this afternoon as
a surface high pressure continues to remain situated over W WA.
Clear skies over the region today will keep VFR conditions
throughout the TAF period, the exception being KHQM - where once
again patchy fog/low clouds will develop along the coast around
10z-16z, leading to MVFR/IFR conditions through early Thursday
morning. North/northeasterly winds will remain around 8 to 10 kts
through Thursday morning.

KSEA...VFR this afternoon as clear skies prevail and persist
throughout the TAF period. N/NE winds 8 to 10 knots into Thursday
morning.

Maz

&&

.MARINE...A broad area of high pressure situated just offshore
will continue to influence the pattern through the end of the
week, with weak onshore flow continuing. Onshore flow will
increase later on Friday as an incoming frontal system approaches
the area waters. Latest guidance indicates at least small craft
westerlies in the Central and Eastern Strait of Juan De Fuca, with
some low-end probabilities of gale force winds. Additional pushes
down the Strait will be likely into early next week.

Combined seas 4 to 6 feet will remain through the rest of the
week, rising around 6 to 8 feet beginning on Sunday.

Maz

&&

.FIRE WEATHER...A few isolated thunderstorms may develop in the
North Cascades near the crest, but chances remain higher to the
east of the local area. Otherwise, high pressure builds with
warmer and dry conditions the next few days with daytime
humidities dipping into the 20-30% range in the driest spots as
light offshore flow develops. This will be short-lived, with a few
days of these warm and dry conditions through Saturday. The return
of cooler air and increased moisture looks to arrive by Sunday and
continue early next week.

&&

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

&&

$$