Strong cyclonic flow encompassed much of the lower 48 on February 6th, stretching from the Pacific Northwest through New England. Western Washington still remained in an active flow pattern, with the polar jet stream overtop the area, contributing to unsettled weather conditions and continued heavy mountain snow.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS SEW wrote it up.
Strong cyclonic flow encompassed much of the lower 48 on February 6th, stretching from the Pacific Northwest through New England. Western Washington still remained in an active flow pattern, with the polar jet stream overtop the area, contributing to unsettled weather conditions and continued heavy mountain snow. The mountains affected the most in this unsettled pattern included the Central and Southern Cascades.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Seattle, WA wrote its last area forecast discussion before the first event at Feb 6, 4:10 AM PST, 3 hours 50 minutes earlier.
Area Forecast Discussion
National Weather Service Seattle WA
410 AM PST Sat Feb 6 2021
.SYNOPSIS...Northwest flow aloft continues across the Pacific
Northwest, in between a ridge over the Pacific and a deep trough
over the central U.S. A series of impulses will drop across the
region this weekend, bringing mountain snow, lowland rain, and
breezy winds. The upper trough to the east may shift west this
week, potentially leading to the arrival of notably colder air for
much of next week.
&&
.SHORT TERM /TODAY THROUGH MONDAY/...Latest satellite imagery
reveals that the overall pattern is gearing up for a 'repeat'
today ongoing northwest flow aloft and another impulse embedded
in the flow approaching closer to western Washington as the
Pacific ridge weakens and advances eastward. Lingering
convergence has aided in maintaining some weak showers over
portions of northern King through southern Skagit counties, but
latest radar products are beginning to show light returns to the
northwest of the area. This next impulse will bring some lowland
rain at times, but more impactfully will maintain snow in the
mountains. The heaviest snow is again expected to be from around
Stevens Pass northward through Mt. Baker, as Snoqualmie Pass will
likely remain mixed with rain/snow at times through the day
(possibly even over to rain for a few hours as snow levels rise
to 3000-3500 feet, before lowering again tonight). The ongoing
winter weather advisories for the Cascades remain on track and
will continue unchanged.
While lowland rain will be generally light and rain rates low
enough to not cause significant concerns today, winds will be
increasing through the morning. Expect to see gusts into the 35 to
45 mph range today across much of the area, with the strongest
gusts closest to the water (both along the coast and through the
Strait of Juan de Fuca, downwind across the San Juan Islands and
around Admiralty Inlet). Rain in the lowlands will generally
taper off by late afternoon, with the exception of a possible
convergence zone maintaining lingering showers through evening.
Meanwhile, northwest flow will provide enough forcing to maintain
showers in the mountains into Sunday. Some renewed showers could
develop over the lowlands again late Sunday into early Monday
morning, and coupled with the arrival of colder air could possibly
provide for some snowflakes down into the lower elevations. At
this point, will need to keep a close eye on how much moisture is
remaining and the timing of colder air pushing in, but current
ensemble guidance doesn't support much by way of lowland snow in
this time window; instead, perhaps some snowflakes in the air will
little if any accumulation with the leading push of colder air.
Otherwise, a drying trend is likely through the day Monday with
cooler air beginning to filter into western Washington. Highs
likely top out in the low to mid 40s Monday. Cullen
.LONG TERM /TUESDAY THROUGH FRIDAY/...The key message for the long
term period remains unchanged with the potential for much cooler
air to arrive across western Washington next week. While ensemble
guidance has shown this potential for several days, the spread
among guidance remains somewhat large. Continued to maintain a
forecast close to the NBM, with low temperatures near or below
freezing from Tuesday morning through much of the week, with
Wednesday and Thursday nights potentially the coldest with
clearing skies and light north/northeast low-level flow. Given
the potential cold air in place, snow levels will likely remain
low through the week and any moisture that moves into the area
under the northwest flow aloft could be in the form of snow.
Will need to keep an close eye on this through the week as there
remains multiple ensemble members that suggest some light snow at
times through the week.
Additionally, guidance continues to suggest that a very cold air
mass will take up residence in portions of southwestern Canada,
allowing Fraser outflow to develop toward midweek. This would
bring some potential for temperatures across western Whatcom
County to plunge below 20 degrees for the coldest nights.
At this point, however, there remains no signal for widespread
lowland snow through the forecast period. Key factors will again
be the strength of the cold air that is in place and the timing of
any moisture. Guidance becomes more split later in the week with
roughly 40% of ensemble solutions favoring a building Pacific
ridge and faster warm up out of the cool cycle, while the majority
for now favors the colder air perhaps remaining into next
weekend. Cullen
&&
.AVIATION...Northwest flow aloft will continue through this
weekend. Rain is currently moving into the Western Washington
area, which combined with the wind has the potential to lower the
visibilities as it moves through the area. Ceilings are expected
to remain in MVFR conditions, with the potential for some rising
to VFR towards the end of the forecast period. The greatest
potential for this to occur is for KBLI, KCLM, and KPAE.
Winds this morning will be south/southwesterly and will be
increasing throughout the morning. By late morning winds will be
shifting to become more west/northwesterly. Gusts are expected to
remain generally 25-30 knots. KBLI, KPAE, and KCLM will likely
see gusts closer to 30-35 knots. Peak winds are expected this
afternoon, around 00 UTC, and will gradually be easing through the
evening hours.
KSEA...MVFR conditions will remain in place through much of the
next 36 hours. There is the potential for conditions to improve to
VFR Saturday night, but confidence is low on the timing of that.
Southwesterly winds increasing throughout the morning with gusts
25-30 knots likely through this afternoon.
Butwin
&&
.MARINE...Increasing winds through the area waters this morning,
with a Gale Warning issued for the Coastal Waters, Strait of Juan
de Fuca, Northern Inland Waters and Admiralty Inlet. West winds
will gradually be turning northwesterly later this afternoon, with
speeds easing Saturday night. Swells are expected to be
northwesterly and will be increasing to 12-15 feet throughout the
day. Come Sunday seas will be gradually be easing. After Saturday
night, Western Washington will be gradually be transitioning to
offshore flow for the beginning of next week. As of right now,
conditions over the area waters look to be fairly quiet next week.
However, the strength of the Fraser River outflow will have to be
monitored as it could create for some gusty conditions through
the Northern Inland Waters.
Butwin
&&
.HYDROLOGY...No river flooding is expected through the next seven
days.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Wind Advisory from 10 AM this morning to 10 PM PST this evening
for Admiralty Inlet Area-Bellevue and Vicinity-Bremerton
and Vicinity-Central Coast-East Puget Sound Lowlands-
Everett and Vicinity-North Coast-San Juan County-Seattle
and Vicinity-Tacoma Area-Western Skagit County-Western
Whatcom County.
Winter Weather Advisory until 10 AM PST Sunday for Cascades of
Pierce and Lewis Counties-Cascades of Snohomish and King
Counties-Cascades of Whatcom and Skagit Counties.
PZ...Small Craft Advisory until 10 PM PST this evening for Grays
Harbor Bar.
Small Craft Advisory until 10 AM PST this morning for Central
U.S. Waters Strait Of Juan De Fuca-Coastal Waters From Cape
Flattery To James Island 10 To 60 Nm-Coastal Waters From
Cape Flattery To James Island Out 10 Nm-Coastal Waters From
James Island To Point Grenville 10 To 60 Nm-Coastal Waters
From James Island To Point Grenville Out 10 Nm-Coastal
Waters From Point Grenville To Cape Shoalwater 10 To 60 Nm-
Coastal Waters From Point Grenville To Cape Shoalwater Out
10 Nm-East Entrance U.S. Waters Strait Of Juan De Fuca-
Northern Inland Waters Including The San Juan Islands-West
Entrance U.S. Waters Strait Of Juan De Fuca.
Gale Warning from 10 AM this morning to 10 PM PST this evening
for Admiralty Inlet-Central U.S. Waters Strait Of Juan De
Fuca-Coastal Waters From Cape Flattery To James Island 10
To 60 Nm-Coastal Waters From Cape Flattery To James Island
Out 10 Nm-Coastal Waters From James Island To Point
Grenville 10 To 60 Nm-Coastal Waters From James Island To
Point Grenville Out 10 Nm-Coastal Waters From Point
Grenville To Cape Shoalwater 10 To 60 Nm-Coastal Waters
From Point Grenville To Cape Shoalwater Out 10 Nm-East
Entrance U.S. Waters Strait Of Juan De Fuca-Northern Inland
Waters Including The San Juan Islands-West Entrance U.S.
Waters Strait Of Juan De Fuca.
Small Craft Advisory until 10 PM PST this evening for Puget
Sound and Hood Canal.
&&
www.weather.gov/seattle2 heavy snow. Local standard time, as filed.
Snow began falling around daybreak on February 6th and continued through the morning hours on February 7th, heavy at times. In a 24 hour period spanning roughly from 8am on February 6th to 8am on February 7th, around 19 inches of new snow fell at Stevens Pass.
Snow began near daybreak on February 6th and continued through the early morning hours of February 8th. Snow was heaviest on the 6th, from around sunrise through midnight. In a 12 hour period from roughly 8am to 8pm on February 6th, Paradise at Mount Rainier picked up around 14 inches of new snow.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2021Every state in 2021This day in weather historyWarnings in Washington, February 2021
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 945321, 945322.