017
FXUS66 KSEW 030500
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
900 PM PST Mon Nov 2 2026
.UPDATE...
Radar has plenty of echoes along the coast but almost all of
that is not reaching the ground. No rain reported at Hoquiam and
Astoria and only 0.01 inches at Quillayute this evening. Under
cloudy to mostly cloudy skies temperatures at 8 PM/04Z were in
the 40s. Main story tonight is the shift to a much more active
weather pattern later in the week into next week with multiple
systems moving through Western Washington. In the short term
current forecast in good shape. Previous discussion follows with
updated aviation and marine sections.
&&
.SYNOPSIS...
A weak system will brush the region tonight, bringing chances
of light rain to the coast tonight and the interior early
Tuesday. The pattern introduces more active weather mid to late
week as a series of systems brings lowland rain, mountain snow,
gusty winds, and the potential for high surf to western
Washington. A brief break in the unsettled weather is possible
Friday night into Saturday, before the next round of active
weather moves in late in the weekend into the first half of next
week.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
An upper level ridge will continue to push inland western
Washington this afternoon with dry conditions expected the
remainder of the day. A cloudy day with high temperatures in the
low to mid 50s across much of the area. A weak system will
brush over the region tonight into Tuesday, bringing a small
chance of showers. The areas that may receive showers would be
locations along the coast, the Olympics, and perhaps the
Northwest Interior. Elsewhere, conditions should remain dry
throughout the day on Tuesday. High temperatures will be a touch
warmer in the upper 50s, maybe low 60s for areas in the
Southwest Interior.
The weather pattern will shift to more active, with a series of
weather systems starting to approach the area starting on
Wednesday. A frontal system looks to move over the area
Wednesday afternoon, bringing widespread rain and high elevation
snow. Most of the rain activity will be focused in along the
coast, Olympics, and the North Cascades with these areas seeing
perhaps a half of inch of rain. Locations in the interior will
likely get rain shadowed and may see a shower or two,
especially areas like the Puget Sound. Snow levels will be
generally around 5000 to 5500, with moisture bringing a few
inches of snow in the higher peaks of the Olympics and Cascades.
Heading into Wednesday evening, we will also see an uptick in
southerly winds, primarily along the Pacific coast, with
gusts around 25 to 35 mph. Locations in the interior could see
gust up to 25 mph at times through the evening. Wind and
precipitation will begin to slowly decrease heading into
Thursday morning. Temps on Wednesday staying in the mid to upper
50s.
Mazurkiewicz
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
Ensemble guidance continues to favor a brief lull on Thursday before
the more active pattern takes hold over the region late Thursday
into Friday. This is shaping up to potentially bring a strong
frontal system with multiple hazards including gusty winds, lowland
rain, and high elevation snow, as well as high surf for the Pacific
coastline. Snow levels around 5000 ft will support heavy snow across
the higher mountain elevations, with 1-2 inches of rain in the lower
mountain elevations. In addition, probabilistic guidance continues
to indicate around a 50% chance of 40 mph or stronger wind gusts
along the coast and areas from Whidbey Island northward. High surf
potential also increases as a large, long period swell moves through
the waters to the coastline, bringing risks for beach erosion and
hazardous conditions along beaches and jetties.
Guidance begins to depict a wider range of potential outcomes toward
the weekend, but these are largely centered around differences in
timing of subsequent systems. If the upper ridge builds a bit more,
this would direct more of the moisture into the B.C. coast. However,
any ridge looks to be rather transient, allowing the next surge of
moisture to return to the region by the end of the weekend. In any
event, it`s clear that we`re entering into a more active period of
weather late this week through the start of next week. Cullen
&&
.AVIATION...
VFR conditions continue this evening and should continue for most
area terminals overnight and into Tuesday with a thick layer of high
clouds moving across the area. This will help to limit fog potential
overnight, but the more sheltered terminals (such as OLM and PWT)
may see localized periods of fog. Winds have become mostly calm with
light offshore flow overnight. N/NE winds 5 kt or less continue into
the day on Tuesday. Cloud cover will also begin to decrease Tuesday
evening.
KSEA...VFR conditions this evening with high OVC clouds over the
terminal. Expect this trend to continue overnight, with cloud cover
limiting any fog development. Light NE winds 5 kt or less,
calm/variable at times.
Mazurkiewicz/62
&&
.MARINE...
The primary marine issue remains the larger seas associated with the
long period swell working through the coastal waters. Seas will
remain around 8-10 feet, largest over the outer zones through
tonight. Seas will continue to ease on Tuesday. Otherwise, attention
turns to a shift to a much more active pattern beginning mid week.
Expect widespread advisory winds across the coastal waters with
probabilities greater than 75% on Wednesday as a frontal system
moves through. Seas will also build late Wednesday into Thursday
over the coastal waters, reaching around 12 to 14 ft. A stronger
frontal system Friday will bring widespread advisory winds and
around a 35% chance of gales to the coastal waters and the eastern
Strait of Juan de Fuca. Expect seas to build more significantly with
this system, bringing around a 20-30% chance of 20 ft seas over the
coastal waters. Additional frontal systems may follow this weekend,
maintaining an active pattern into the start of next week.
Cullen/62
&&
.HYDROLOGY...
River flooding is not expected through the next seven days. However,
a series of increasingly moist weather systems will bring rain
(and high mountain snow) to the region this week, especially
Friday onward. While current forecasts are not expected to cause
flooding, this will begin to saturate soils and raise base
flows that could bring a concern with subsequent storms systems.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 4 AM PST Tuesday for Coastal Waters
From Cape Flattery To James Island 10 To 60 Nm-Coastal
Waters From James Island To Point Grenville 10 To 60 Nm-
Coastal Waters From Point Grenville To Cape Shoalwater 10
To 60 Nm.
&&
$$
NWS SEW Office Area Forecast Discussion