Renton, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

546
FXUS66 KSEW 151102
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
402 AM PDT Thu May 15 2025

.SYNOPSIS...A weak upper level ridge remains overhead early
this morning, but this will quickly be replaced as the next
frontal system crosses Western Washington today. This will usher
in the next round of steadier rain across the area through the
evening. An unsettled weather pattern will remain in place
across the Pacific Northwest this weekend through early next
week, maintaining widespread clouds and rain showers.

&&

.SHORT TERM /TODAY THROUGH SATURDAY/...A few lingering showers
in a loosely organized convergence zone are evident on radar
this morning, but this is continuing to decrease this morning as
onshore flow decreases and increasing subsidence develops over
the region. The next frontal system is already approaching the
coastal waters and coming into the view of radar coverage this
morning. This disturbance will reach the coastline by mid-
morning and continue to slowly advance inland later today
bringing a bit more widespread rainfall. With colder air aloft,
expect some snow in the mountains above around 4,500 feet as
this system reaches inland. Additional disturbances will
maintain cool, cloudy conditions into the weekend, with shower
chances continuing. Will need to continue to monitor the
Saturday afternoon and evening time period for a few
thunderstorms as instability increases. The chances remain
highest (around 15%) for areas south and east of Puget Sound and
lower elsewhere. Otherwise, temperatures through the period
generally in the upper 50s to around 60, or around 5 degrees
below normal for this time of year.                 Cullen

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...The cool and
showery pattern will continue through much of Sunday, with
another brief lull Sunday night as heights rise over the region
in between disturbances. This appears to be a quite short break,
however, with good ensemble agreement supporting generally
zonal flow that will keep the door open to abundant cloud cover
and rounds of showers as disturbances move through the region.
Temperatures generally hold within a few degrees of seasonal
normals and change little day to day.          Cullen

&&

.AVIATION...Northwesterly flow will become more westerly
Thursday morning as a frontal system pushes through Western
Washington. Majority of terminals are VFR early this morning.
Expect ceilings to lower throughout the morning hours into MVFR
as lower level stratus fills in. Rain will will begin to move
into the coastal terminal around 16z-18z, and will reach the
interior terminals around 19z- 21z. Rain is expected to remain
light with this system. Reduction in visibility is also possible
to 3-5 miles (10-15% chance). Guidance is hinting at seeing
some IFR ceilings/visibilities along the coast and Strait. Some
models are hinting at potentially seeing some improvement
Thursday afternoon/evening for terminals along Puget Sound into
VFR; however confidence is low at this time.

Southerly/southwesterly flow along interior terminals, with
sustained speeds of 8-13 kt (stronger speeds along BLI), decreasing
to 4-6 kt Thursday evening. Northwesterly/westerly flow along the
coast and Strait at 5-7 kt, becoming more southerly/southwesterly
Thursday evening.

KSEA...VFR ceilings will lower MVFR this morning as a frontal system
pushes through the terminal, bringing light rain. Reductions in
visibility are also possible down to 3-5 miles. Guidance is
struggling on whether conditions will be able to improve into VFR
later this afternoon/evening. At this time confidence is low, and
plan to keep MVFR persisting throughout the TAF period at this time.
Southwesterly flow  at the terminal with sustained speeds of 8-10
kt, decreasing to 5-6 kt late Thursday night into Friday morning.

29

&&

.MARINE...Winds along the Central and East Strait have been
subsiding early this morning and the Small Craft Advisory has
been allowed to expire. A frontal system will traverse the
waters late Thursday into Friday, with winds tracking to remain
below small craft criteria. However, an isolated gust around 21
kt cannot be ruled along the coastal waters. The front will
weaken as it moves onshore on Friday. Surface high pressure will
rebuild Saturday into Sunday offshore, likely bringing a round
of small craft winds over the coastal waters and Strait of Juan
de Fuca. High pressure will weaken late Sunday night as a
stronger system moves over the waters on Monday.

Seas will hover around 4-6 ft on Thursday and will build on Friday
to 7-8 ft. Saturday seas will decrease slightly, before increasing
again on Sunday to 8-10 ft.

29

&&

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

&&

$$