552
FXUS66 KSEW 012244
AFDSEW

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

.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 THURSDAY/...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 with strong high pressure offshore.
Clouds continuing to scatter this afternoon and evening with VFR
conditions expected. Onshore flow will keep the low level air mass
moist with low clouds and MVFR conditions returning by 12z. Low
clouds will lift and scatter Tuesday afternoon (similar to today)
with VFR prevailing. 33

KSEA...Clouds scattering this evening with VFR conditions. Winds
W to NW to 10kt, becoming S and easing after 09z. Low clouds and
MVFR conditions returning by 12z. 33


&&

.MARINE...A westerly surge through the strait tonight with gales
expected. Small Craft Advisory winds also in the Northern Inland
Waters and Admiralty Inlet. Expect another surge down the strait
Tuesday evening amd again possibly Wednesday. A thermal trough
will form along the coast on Thursday with the flow turning
offshore. 33


&&

.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 from 5 PM this afternoon to 5 AM PDT
     Tuesday for Admiralty Inlet-Northern Inland Waters
     Including The San Juan Islands.

&&

$$