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000
FXUS66 KSEW 172227 CCA
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
322 PM PDT Wed Apr 17 2024

.SYNOPSIS...Dry spring time weather with cool overnight
temperatures and warmer than normal high temperatures will linger
through the end of the work week. A weakening front will bring
increased clouds, cooler temperature, and widespread precipitation
Saturday afternoon and evening followed by lingering showers Sunday.
Warmer and dry weather will kick the new week off Monday.

&&

.SHORT TERM /TONIGHT THROUGH SATURDAY/...Sunny skies with
widespread temperatures in the mid to upper 50s this afternoon.
Mild conditions will linger into the evening setting up another
night with temperatures on the cool side of normal. HREF and NBM
ensemble data showing a 20-30% chance of temps dipping to freezing
again tonight in the lowlands - mainly limited to Lewis County -
cool, but a bit warmer than last night.

An upper level trough moving down the backside of the offshore
ridge late tonight and is expected to linger in the area into
Thursday night. This continues to be a dry feature with perhaps a
few more mid and high clouds and another sunny day. Thursday highs
will be a little warmer - pretty solidly in the 60s.


Friday looks to be the warmest day as the upper level trough
kicks east, and the offshore upper level ridge building.
Importantly low level flow becomes more easterly with gusty
easterly winds in the Cascade Foothills. High temperatures will
tip a bit higher into the upper 60s and lower 70s.

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...The distribution in the
ensembles continue to highlight the offshore ridge moving through
Western Washington Friday night followed by a negatively tilted
front Saturday. This will bring widespread rain and some gusty
winds then lingering showers Sunday. There looks to be a good
chance an high pressure to some degree Monday with drier and
warmer weather to open the new week. There are enough members that
keep some potential for precip Tuesday, but there are higher odds
for generally dry weather lingering into mid week - typical Spring
weather either way.

&&

.AVIATION...VFR skies (with cumulus over in the Cascades and
Olympics) will continue this afternoon and into Thursday as upper
level ridging continues to build offshore over the Pacific Ocean
(with a thermal trough underneath). The ridge building and moving
inland on Thursday will decrease the chance for morning clouds and
low visibilities (compared to earlier today), but cannot rule out a
couple isolated areas seeing patchy fog or frost early Thursday
morning (due to weak north flow aloft). Winds at the surface will
remain northerly through the forecast, with areas along the coast
turning easterly as the ridge moves over Thursday. The highest winds
will occur Wednesday/Thursday with 14 to 20 kt gusts possible.

KSEA...VFR skies with cumulus east in the Cascades gradually
decreasing as an upper level ridge moves in. Winds will remain
northerly through the TAF period, with gusty winds up to 15 to 20 kt
possible this afternoon/Thursday afternoon.

HPR

.MARINE...An upper level ridge will continue to build offshore over
the Pacific, and will move inland on Thursday. A surface trough will
also remain over the coast Thursday into Friday. Gusty east winds of
10 to 20 kt are possible in the Strait of Juan de Fuca Thursday, as
well as gusty northerly winds in the Puget Sound waters of up to 20
kt. Small probability that the winds exceed 20 kt, will continue to
monitor the potential need for a small craft advisory Thursday for
these areas. A trough and surface system will impact the region this
weekend, with gusty winds possible in some of the inland and coastal
waters Friday through Monday.

Expect seas to remain around 3 to 6 ft through the period.

HPR

&&

.HYDROLOGY...No river flooding expected for the next 7 days.

&&

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

$$