691
FXUS66 KSEW 212101
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
201 PM PDT Fri Jun 21 2024

.SYNOPSIS...After a warm day today, onshore flow will increase
over the weekend allowing for slight cooling Saturday and much
more cooling on Sunday. Showers will also return by Sunday. While
temperatures will rebound slightly early next week, temperatures
will remain mild with occasional chances for precipitation.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY/...Outside of some thin cirrus
and some stratus along the immediate Pacific Coast, mostly clear
skies are present across the region this afternoon. As of 2pm,
temperatures were largely around 80 degrees in the interior
lowlands (cooler near waterways, and warmer across the SW
interior). Temperatures will likely rise another 2-4 degrees this
afternoon. This will result in HeatRisk levels mainly in the
minor/yellow category with some spots in the urban area cresting
in the moderate/orange category. The heat will be relatively short
lived as onshore flow increases over the weekend. Highs on
Saturday will be 2-5 degrees cooler than the highs today, while
Sunday will see more significant cooling with temperatures in the
60s. Areas of precipitation and breezy conditions will accompany
these cooler temperatures on Sunday, with gusts of 20-25mph
during the day. Weak ridging tries to build in again Monday into
Tuesday allowing a rebound in temperatures back to near to above
normal.

.LONG TERM /TUESDAY THROUGH FRIDAY/...After another mild and
likely pleasant day on Tuesday, the door will remain open for
additional weak systems to roll through the region next week. This
will keep temperatures in check and bring an occasional chance of
precipitation to the region. At this time no significant weather
hazards are anticipated.
-Wolcott-

&&

.AVIATION...High pressure remains in place over the region, moving
east through Saturday. Continued westerly flow aloft with light flow
in the lower levels becoming onshore tonight into Saturday. This
will maintain VFR conditions under generally clear skies for much of
the area through evening, but low stratus offshore will return to
the coastline up the lower Chehalis this evening. The stratus is
unlikely to make it to KSHN/KOLM tonight.  Northerly winds this
afternoon will become light and see a switch to southerly, mostly
after 09z-12z Saturday. Some mid level clouds increase through the
day Saturday.

KSEA...VFR conditions continue under generally skies through the
period. Expect north surface winds decreasing late evening
and becoming southerly by 12z Saturday.

&&

.MARINE...High pressure over the coastal waters with lower
pressure inland today. Winds relatively light over most
waters, but expect a westerly push through the Strait of Juan de
Fuca this evening. The current advisory is unchanged. Meanwhile,
seas over the coastal waters remain rather steep as a short-period
wave group dominates. A passing disturbance Saturday will bring a
stronger push of west winds through the Strait tomorrow evening.
While guidance does suggest this will be stronger than today`s
winds, the likelihood of widespread gales through the Strait remains
lower (closer to 50%). As a result, have maintained the current gale
watch and will wait until a future update to make the determination
of SCA or gale warning for this upgrade.

Looking ahead to next week, high pressure remains situated over the
waters with no significant winds expected at this time. Seas will
build closer to 8 feet by Monday morning, though, as a larger west
wave group arrives. Seas then subside through the remainder of the
forecast period.   Cullen

&&

.FIRE WEATHER...Temperatures will be warm through Saturday, with
many locations in the Cascade foothills and high ridges achieving
relative humidity values of 15 to 25 percent. This drier pattern
will be short lived as onshore flow and a weak weather system
returns on Sunday and brings up the relative humidity values.
Unsettled weather is expected late next week as the offshore low
pressure system remains in the area. This will be evaluated by
early next week for any potential for lightning or additional
rainfall.

Kristell

$$

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory from 5 PM this afternoon to 5 AM PDT
     Saturday for Central U.S. Waters Strait Of Juan De Fuca-
     East Entrance U.S. Waters Strait Of Juan De Fuca.

     Gale Watch from Saturday evening through late Saturday night for
     Central U.S. Waters Strait Of Juan De Fuca-East Entrance
     U.S. Waters Strait Of Juan De Fuca.

&&

$$