Strong Fraser outflow over the north interior of Western Washington continued to intensify during the day on February 11. As a result, strong and gusty winds developed over portions of Western Whatcom and San Juan Counties.
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 Fraser outflow over the north interior of Western Washington continued to intensify during the day on February 11. As a result, strong and gusty winds developed over portions of Western Whatcom and San Juan Counties.
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 11, 3:27 AM PST, 4 hours 33 minutes earlier.
Area Forecast Discussion
National Weather Service Seattle WA
327 AM PST Thu Feb 11 2021
.SYNOPSIS...The cold and active pattern continues through the week
as a series of systems move through Western Washington,
introducing snow throughout the region. The first system will
arrive later today. The second and likely more impactful system is
on track to arrive Friday night, lasting into Saturday and
providing widespread snowfall to western Washington. Temperatures
may rebound into early next week, but the unsettled pattern is
likely to remain.
&&
.SHORT TERM /TODAY THROUGH SATURDAY/...The first in a two part
series of weather systems will be arriving today to bring a chance
for snow to much of Western Washington. Impactful accumulations of
3-6 inches will be possible, primarily for the Southwest interior
and portions of South Puget Sound. A Winter Storm Warning is in
effect for these areas beginning this morning and lasting through
Friday evening. Easterly winds may moderate some of these totals
as they warm and dry the air while descending from the Cascade
crest.
Fraser outflow will be on the way up this morning, causing windy
and low wind chills for Whatcom and Skagit counties. Northeasterly
winds will continue through Puget Sound this morning before
becoming more easterly later in the day today. Snow total wise,
areas from Tacoma south could pick up 1-3 inches with higher
totals even further south. The Seattle area may only see about an
inch, with even less going north.
Looking ahead to the next system arriving Friday night, while
there is still uncertainty despite being close to the onset of the
event, this event will aim to provide more snow to more of the
area. For this event, a Winter Weather Watch is dictated to go
into effect beginning Friday morning and lasting through Saturday
afternoon. Opted not to upgrade this product in this morning's
forecast package in order to allow the afternoon package to
upgrade to a warning with the most recent model data available.
The most snow is still likely to accumulate in the Southwest
Interior, Cascades of Pierce and Lewis counties, as well as in
areas south of Tacoma, but a range of 6 to 13 inches is possible.
Uncertainty in exact amounts and placement of significant
accumulation has some roots in continuing easterly winds that will
strengthen Friday night into early Saturday morning. It remains
to be seen how efficient the saturation of the airmass is as it
battles drier easterly winds in order to further determine a
better range of possibilities. Probabilistic data continues to
suggest that there is a better than 50% chance that the Seattle
area sees between 4-6 inches of snow.
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...Sunday may see residual
snow showers, but likely not widespread in coverage, before
tapering slightly. Temperatures will slowly rebound into early
next week, with unsettled conditions sticking around. Temperatures
will still be below normal, so at this point, it is uncertain as
to what types of precipitation can be expected in the early week
time frame. What we do know, is that there likely will not be much
of a reprieve in active weather going into next week. Stay tuned
for forecast updates.
Kristell
&&
.AVIATION...A BKN-OVC deck present over the area early this morning,
with a few bands of light snow noted near KBLI, KCLM, and KPAE. A
light dusting could be possible at these airfields if a band
persists. The snow associated with the first in a series a winter
storms system is still offshore, with snow still S/SW of KHQM as of
2AM. VFR conditions should prevail through the period at most TAF
sites-the best chance for MVFR ceilings will be KOLM and KHQM where
periods of snow can be expected over the next 24 hours. Light snow
could make it up to KSEA and KBLI, but little to no accumulation is
expected and largely think snow will remain just south. North wind
generally 10-15 kts, becoming gusty later this morning 20-25kts
(potentially 30-35kt at KBLI closer to Fraser Outflow).
KSEA...BKN-OVC VFR thru the period. A few flurries/light snow
showers cannot be ruled out early this morning-no impacts.
Widespread snow will approach from the south later this morning,
possibly bringing some light snow to the airfield. Worst case
scenario is around an inch of accumulation thru thru day but more
impactful snow will remain south. North wind 8-12kts with gusts 20-
25kt beginning late morning and likely carrying through Friday-more
of an easterly component likely this evening/overnight.
Kovacik
&&
.MARINE...High pressure to the north and east of Western Washington
with low pressure offshore is continuing the Fraser outflow over the
northern interior waters early this morning. A Gale Warning will
remain in effect for the Northern Inland Waters, the Strait of Juan
de Fuca, and the Northern Coastal/Offshore Waters. Winds across
these waters could reach 40kt at times. Elsewhere, a SCA will cover
the remaining offshore/Coastal waters, Admiralty Inlet, and Puget
Sound, with some of these northerly winds turning towards the east
and making it towards to Grays Harbor and the Southern Offshore
waters. The SCA will become replaced by a Gale Warning for the
Southern Coastal/Offshore Waters beginning at 7AM this morning.
Winds will remain elevated through the overnight period and into
Friday. It currently appears that by Friday afternoon or evening the
Fraser outflow will subside and, in turn, the easterly winds will
really kick in as the pressure gradient strengthens. Model guidance
suggest a substantial surge of easterly wind down the Strait Friday
night-potentially approaching Storm criteria. Will have to monitor
that. OTherwise, could also see another round of Gales offshore,
with a SCA a sure bet for the remaining waters. Will begin to
address these headlines over the next few forecast updates.
Outside of the winds, winter precipitation should be expected, which
is likely to carry impacts. Moderate to heavy precip is likely over
Southern Puget Sound and the Southern Offshore/Coastal Waters today
and then across all waters Friday night into Saturday. Swells will
remain 5ft or less thru Friday, increasing quickly to 10-12 ft
Saturday and continuing into next week.
Kovacik
&&
.HYDROLOGY...No river flooding is expected over the next 7 days.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Winter Storm Warning from 6 AM this morning to 6 AM PST Friday
for Hood Canal Area-Lower Chehalis Valley Area-Southwest
Interior-Tacoma Area.
Winter Storm Watch from Friday morning through Saturday
afternoon for Cascades of Pierce and Lewis Counties-Hood
Canal Area-Lower Chehalis Valley Area-Southwest Interior-
Tacoma Area.
Wind Advisory until 10 AM PST Friday for North Coast-San Juan
County-Western Whatcom County.
Winter Storm Watch from Friday afternoon through Saturday
afternoon for Admiralty Inlet Area-Bellevue and Vicinity-
Bremerton and Vicinity-East Puget Sound Lowlands-Everett
and Vicinity-Seattle and Vicinity.
Wind Advisory from 7 AM this morning to 10 AM PST Friday for
Central Coast.
Wind Advisory until 4 PM PST this afternoon for Western Skagit
County.
PZ...Small Craft Advisory until 7 AM PST this morning for Coastal
Waters From Point Grenville To Cape Shoalwater 10 To 60 Nm-
Coastal Waters From Point Grenville To Cape Shoalwater Out
10 Nm.
Gale Warning from 7 AM this morning to 11 AM PST Friday for
Coastal Waters From Point Grenville To Cape Shoalwater 10
To 60 Nm-Coastal Waters From Point Grenville To Cape
Shoalwater Out 10 Nm.
Small Craft Advisory until 11 AM PST Friday for Admiralty Inlet-
Coastal Waters From James Island To Point Grenville 10 To
60 Nm-Coastal Waters From James Island To Point Grenville
Out 10 Nm.
Gale Warning until 11 AM PST Friday 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-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.
Freezing Spray Advisory until 10 AM PST this morning for
Northern Inland Waters Including The San Juan Islands.
Small Craft Advisory until midnight PST tonight for Puget Sound
and Hood Canal.
&&
www.weather.gov/seattle1 high wind. Local standard time, as filed.
High winds were reported around Sandy Point Shores on February 11 in strong Fraser outflow out of the northeast. Gusts were reported by observation sites C1394 and KWAFERND4 of 71 and 72 mph, respectively. These gusty winds also made for cold morning wind chills.
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: 945336.