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000
FXUS66 KSEW 261015
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
315 AM PDT Fri Apr 26 2024

.SYNOPSIS...Heavy rain from Thursday will trickle down to showers
for the remainder of the day Friday. Additional frontal systems
will impact the region through the weekend and into next week.
This will keep the shower activity daily into next week. Rain
amounts stay light except for the Cascades Sunday afternoon into
Monday morning. Below average temperatures will also continue with
highs in the 50s.

&&

.SHORT TERM /TODAY THROUGH SUNDAY/...Current surface analysis
showers a surface cold/occluded front over Forks draping into the
Southwest Interior and into Oregon. An upper level trough sits
directly overhead western Washington for Friday as it moves
onshore. A surface low is also centered off the coast in the
Pacific. The overall stacking of this system indicates weakening
as it comes onto land and is slowed down. Radar imagery shows a
couple pockets of showers/rain continuing in the Cascades and
Olympics this morning, with isolated showers south of Olympia
moving north. Some of the moisture is wrapping around the low in
the Pacific, aided by southwest/west flow aloft keeping the air
at least somewhat moist before dry air aloft intrudes in behind
the trough. A couple smaller shortwave troughs will still pass
over the region Saturday and Sunday

Long story short, precipitation chances will continue through the
weekend. Although not an all day washout, multiple rounds of
showers will be possible for the remainder of Friday, Saturday,
and Sunday. Convection is not anticipated, but the cool air
aloft/warmer surface temperatures may support a graupel shower. The
heaviest precipitation from yesterday`s system has mostly
concluded, and many areas received anywhere from a half of an inch
of QPF to near 2 inches. For the remainder of Friday, lowland
areas may see a couple more tenths of an inch of QPF, with close
to a half an inch possible in the Cascades/Olympics. Same amounts
are expected for Saturday. For Sunday, heavier precipitation may
set up over the Cascades, increasing QPF totals to around an inch
(potentially just over). Friday will be the warmest day in the
short term with highs around 60. This drops into the mid 50s
Saturday and Sunday, well below average. Winds remain light out of
the south/west at 5 to 10 miles per hour, but a few gusty winds
are possible near waterways.

.LONG TERM /MONDAY THROUGH THURSDAY/...Additional systems are
expected to impact the region next week. The wettest day at this
time appears to be Monday, with a strong mid-latitude cyclone/jet
streak dropping down from Canada. Some models have hinted
convection with this system on Monday, although activity is
expected to remain showery and isolated in nature. After
Wednesday, there remains disagreement into how strong an
additional trough will dig down the west coast. Some models have
it staying in Canada, while others have it dropping into northern
California. A couple more ensembles members (compared to
yesterday) are even showing some ridging over the Pacific
Northwest Thursday. Monday/Tuesday remain cool in the 50s, but
could see 60s make a return next Wednesday/Thursday. Winds will
remain light as well in the forecast.

HPR

&&

.AVIATION...Light southwest flow aloft with an upper level trough
slowly moving over the Pacific Northwest. Light south-southwesterly
surface flow, with northerly flow across the northern Puget Sound
terminals after 23Z. A mix of VFR and MVFR CIGs this morning, with
gradual improvement to VFR after 20Z, with the exception being MVFR
CIGs through most of the day at HQM. Brief VSBY restrictions
possible at times, with light periods of rain and drizzle giving way
to scattered showers by late morning into the afternoon.

KSEA...Currently VFR, though expect predominantly MVFR CIGs through
20Z with drizzle and periods of light rain. Brief VSBY restrictions
cannot be ruled out as well. Probability of MVFR around 50% through
this timeframe. Conditions should gradually improve as CIGs lift to
more solid VFR levels into the afternoon with rain tapering off to
showers. South to southwest flow 5 to 10 kt through the TAF period.

Davis

&&

.MARINE...Surface low pressure continues to weaken as it moves
further inland this morning. No headlines currently in effect with
marginal northerly wind gusts to near 20 kt possible over the far
offshore waters through early this evening. The next frontal system
is poised to move over the area waters Saturday, as a warm front
lifts across the waters, turning flow to the southwest with advisory-
level wind gusts likely over the offshore waters late Saturday
morning into the afternoon (80-90% chance).

Additional frontal systems will cross the area waters through next
week as an active weather pattern continues.

Seas ranging from 5 to 7 feet, rising to 6 to 9 feet later this
afternoon and closer to 10 feet into Saturday night and Sunday,
lingering around 8t 10 feet through early next week.

Davis

&&

.HYDROLOGY...No river flooding is anticipated at this time over
the next seven days.

&&

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

$$