193
FXUS66 KSEW 020335
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
835 PM PDT Mon Jul 1 2024

.UPDATE...With daytime heating coming to an end, temperatures
today peaked right around normal. Strong onshore flow overnight
will generate a cloudy morning across western Washington, causing
temperatures to be a few degrees cooler tomorrow. Tuesday is on
track to be the coolest day of the foreseeable future ahead of
much warmer and dry conditions with a strong high pressure ridge
on track to develop over the southwestern US. No updates to the
forecast this evening.

&&

.SYNOPSIS...Near-normal temperatures through Wednesday but a
strong upper-level ridge looms upstream. This ridge will move
over Western Washington Friday and remain over the area through
the weekend. Here we`ll see the warmest weather of the year so far
which could last into next week.

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY/...Upper-level ridge
positioned over the NE Pacific between 130-140W with its axis
nosing into the BC coast. Downstream, expansive troughing is
present throughout the Canadian Prairies and into the
Intermountain West. Here locally, a subtle shortwave is now east
of the Cascades. Under northwesterly flow, spotty shower activity
is present over the central Cascades and southwest interior but
conditions are to be mostly dry. Tonight, strong onshore will
increase stratus across western Washington. Overnight lows will
range between the upper 40s to mid 50s.

A cloudy start to the day on Tuesday before eventually giving way
to afternoon sunshine. High temperatures won`t stray too far from
normal with highs in the mid 60s to near 70. However, it`ll be
the coolest day for the foreseeable future as the aforementioned
upper-level ridge draws near. Temperatures are expected to warm
to the mid to upper 70s for the lowland interior and foothill
locations on Wednesday. For the 4th, models are indicating the
near 600 dm ridge center over CA greatly influencing conditions
here in W WA. High temperatures are to top out well into the 80s,
well above average for early July. Coastal areas will remain in
the 60s. Overnight lows are to bottom out mostly in the lower 50s.

.LONG TERM /FRIDAY THROUGH MONDAY/...The heat really begins to
ramp up as we settle into the long term period. The ridge will
amplify over the region during the weekend. High temperatures
will top out in the upper 80s to mid 90s for the interior, upwards
of 10 to 13 degrees above average as widespread minor to moderate
heat risk is expected to develop. Minimal cooling is possible
early next week but the question is by how much. Some disagreement
in how the upper-level pattern will evolve exists but confidence
is leaning towards well-above average temperatures remaining.

McMillian

&&

.AVIATION...NW flow aloft continues with strong high pressure
offshore. Satellite shows a group of cumulus clouds (with bases
around 4,000 to 5,000 feet) over Puget Sound into the Cascades, with
a thicker band of clouds off the coast. As onshore flow restores a
moist airmass overnight, low clouds in the low-end VFR/MVFR criteria
are expected Tuesday morning. IFR is possible along the coast.
Coverage will move inland overnight, reaching east of the Olympics
past 12Z into Puget Sound. The CIGs will scatter out Tuesday morning
into the afternoon with VFR conditions. Winds will drop to light and
variable overnight, becoming southerly Tuesday morning 4 to 8 kt,
and northwest by late Tuesday afternoon. Higher winds are expected
along coastal areas to 15 kt.

KSEA...Scattered to broken cumulus clouds around the terminal will
hang around through tonight. As moist air reaches the terminal from
the onshore push, expect CIGs to fall to MVFR after 12Z, scattering
out mid to late Tuesday morning. Winds will continue out of the
northwest to 10 kt through the evening, switching to south after 09Z
until late Tuesday afternoon (back to north).

HPR

&&

.MARINE...Northwesterly flow continues aloft with high
pressure/ridging building over the Pacific. Breezy and gusty winds
continue tonight in the Central/East Strait of Juan de Fuca (gales),
and portions of the Admiralty Inlet and Northern Inland Waters
(breezy winds for small craft). Added a new small craft advisory for
breezy northwest winds in the outer coastal waters - expected to
reach 20 to 25 kt. The winds in the outer coastal waters are
expected to continue through Wednesday. Seas will also reach 8 to 10
feet with this northwesterly push, before falling to 5 to 7 feet
Thursday into next weekend. Additional pushes are possible Tuesday
and possibly Wednesday evening.

HPR

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Gale Warning until 5 AM PDT Tuesday for Central U.S. Waters
     Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of
     Juan De Fuca.

     Small Craft Advisory until 5 AM PDT Tuesday for Admiralty Inlet-
     Northern Inland Waters Including The San Juan Islands.

&&

$$