FXUS66 KSEW 031550
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
850 AM PDT Thu Apr 3 2025

.UPDATE...Showers have tapered off this morning as ridging builds
offshore for drier weather. Clouds and localized fog across the
interior portion of Western Washington will clear for sunshine
this afternoon. No forecast updates this morning.

&&

.SYNOPSIS...High pressure will build into the region through the
remainder of the week, allowing conditions to dry out and warm up.
Wet and cooler conditions are on track to return by the end of the
weekend as troughing settles into the Pacific Northwest.

&&

.SHORT TERM /TODAY THROUGH SATURDAY/...Latest radar imagery shows
light shower activity east of the Puget Sound and along the
Pacific Coast early this morning slowly tapering off as dry
northerly flow develops aloft. Temperatures will continue to lower
into the 30s this morning with areas of patchy frost possible
mainly south of the Puget Sound through Lewis County. As drier air
continues to move into the region throughout the day, sky cover
will clear by the afternoon with highs peaking today in the mid to
upper 50s.

High pressure will continue to amplify and shift inland into the
weekend, with high temperatures reaching the 60s across the
lowlands by Friday with plenty of sunshine across the interior.
Temperatures will follow a warming trend into Saturday, with areas
along the Cascade Foothills reaching highs in the lower 70s.
As the next storm system slowly approaches, cloud cover will
increase throughout the day Saturday but with plenty of sun breaks.

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...The next chance for
widespread precipitation increases throughout the day Sunday as
high pressure moves eastward and a front moves inland across the
Pacific Northwest. Southwest flow will maintain mild temperatures
in the 60s across the lowlands with snow levels between 6000-7000
feet on Sunday. A cold front will push inland late Sunday into
Monday, maintaining widespread showers as temperatures cool and
snow levels lower. Moist westerly flow will continue through the
first half of next week, with periods of breezy winds, persistent
rainfall over the lowlands, and periods of accumulating mountain
snow.

15

&&

.AVIATION...North winds aloft as an upper level ridge begins to move
eastward towards western Washington. Variable to light southeasterly
surface flow early this morning, with mostly VFR conditions, through
some MVFR cigs are holding on across the Puget Sound, as well as fog
at OLM. Ceilings should continue to scatter and lift this throughout
the day, becoming mostly clear by this evening with VFR conditions
continuing into the overnight hours. With light winds continuing
again overnight tonight into Friday, will need to assess the extent
of additional low stratus and fog development into early Friday
morning. As for winds, expect a transition to north/northwest flow
early this afternoon between 5 and 7 kts across most terminals,
generally after 20Z.

KSEA...VFR to MVFR conditions with a broken low stratus deck in
place this morning, with light S/SE 4 kt or less. This will persist
through much of the morning hours before VFR cigs return for the
rest of the TAF period. A transition to northwesterly flow is likely
after 20Z today, with speeds in the 5 to 7 kt range through 23Z,
increasing slightly to 7 to 8 kts after 00Z. Speeds look to drop
back to around 5 kts after 03Z. Will need to assess potential for
another round of fog/low stratus early Friday morning with
probabilities of around 15-25% between 12-18Z Friday.

21/62

&&

.MARINE...Surface high pressure will continue to build offshore,
easing marine winds and seas through the rest of the week. Benign
conditions will continue through the weekend, before a frontal
system approaches the waters Sunday evening. Here, we will likely see
elevated winds and seas return to the coastal waters.

Combined seas 3 to 5 feet through the rest of the week and into the
weekend. Seas will start to gradually build upwards by Sunday
ranging from 9 to 12 feet.

21

&&

.HYDROLOGY...No river flooding is expected over the next 7 days.

&&

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

$$