A frontal system brought heavy snow to the North Cascades over a prolonged period.
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.
A frontal system brought heavy snow to the North Cascades over a prolonged period.
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 Mar 2, 3:30 AM PST, 30 minutes earlier.
Area Forecast Discussion
National Weather Service Seattle WA
330 AM PST Thu Mar 2 2017
.SYNOPSIS...Upper level ridging will slowly break down today as a
deep upper trough in the Gulf of Alaska digs south, pushing a cold
front through the region on Friday and bringing breezy conditions
and heavy mountain snow. Behind the front, another cold air mass
will lower snow levels for Saturday through Monday with lowland snow
showers possible Sunday and Monday mornings. Cold air will exit next
week, allowing temperatures to rise closer to normal on Tuesday and
Wednesday. Rain will remain in the forecast for much of the forecast
period.
&&
.SHORT TERM...Some showers on the coast and some snow over the
Cascades this early morning while generally dry elsewhere according
to radar imagery at the time of this writing.
Upper level ridging will continue to flatten through the day today
with a couple of shortwave disturbances allowing for some pre-
frontal showers to develop over the northern Olympic peninsula and
along the Canadian border...extending into the North Cascades. The
main front does not look to impact W WA until late this afternoon
and into tonight. With that...inherited Winter Storm Warning will go
into effect for the North Cascades at 4 AM this morning while
remaining two-thirds will hold off til noon today. Current models
suggest slightly lower amounts than previous forecast...but still
falling within same range provided in associated statements...so no
need for any tweaks there. Front stalls until better upper level
support moves down Friday afternoon finally giving the push to move
eastward...bringing best chances for precip. Breezy to windy
conditions are expected along with the frontal approach. The front
looks to move on Friday night creating a bit of a lull in activity
which...of course...does not last very long as rain looks to kick
back in by Saturday afternoon in advance of an upper level low
making its way over the coastal waters. This feature still looks on
track to start bringing snow levels down to around 1000 ft
Saturday...bringing the potential for mixed precip to some locations
Saturday night.
Inherited forecast generally on track...albeit a bit on the
depressing side. No major changes made. SMR
.LONG TERM...The upper level low will devolve to an open trough as
it passes through W WA Sunday. Cold air will tighten its tyrannical
grip on the area as both Sunday morning and Sunday night/Monday
morning look to bring snow levels down to under 500 ft...bringing up
the prospect of lowland snow yet again. Thankfully...at this time
amounts continue to look rather fledgling. After reaching their
nadir Monday...temperatures waste no time rebounding Tuesday and
through the remainder of the forecast period as models continue to
trend warmer for the remainder of the week ahead with afternoon
highs in the lowlands reaching into the 50s by the second half of
the upcoming week. The pattern continues to look active however as
upper level ridging remains offshore allowing systems to slide down
its leading edge into W WA. While that ridge does finally start to
creep inland by mid-week...it would be a dirty ridge at best as
models continue to show precip over the area. So while there may be
a lull here and there...the long term continues to look wet. SMR
&&
.AVIATION...Westerly flow aloft today. A frontal system will reach
the area today. At the surface, southeasterly flow this morning
ahead of the approaching front. South to southeast flow will
increase this afternoon into the evening as a front moves into the
area. The air mass is moist and stable.
Multiple cloud layers to 12000 feet with a broken to overcast layer
in the 3500 to 4500 foot range. Rain beginning this morning with
ceilings eventually lowering to 1000-2000 feet by the middle of the
afternoon. Some improvement in the ceilings tonight.
KSEA...Broken to overcast layer at 3500-4500 feet with temporary
ceilings near 2500 feet until 15z. Ceilings lowering to around 2000
feet by late afternoon. Rain beginning this morning and continuing
through the afternoon. Southeast wind 4 to 8 knots.
Felton
&&
.MARINE...Low level flow southeasterly today. A frontal system will
move through the waters later today and tonight with small craft
advisory winds all waters except the Central Strait of Juan de Fuca.
Moderate onshore flow will follow the front on Friday. A surface low
will move into the offshore waters Saturday then move onshore as a
trough on Sunday. Another front will reach the area Monday. Felton
&&
.HYDROLOGY...The past few runs of the GFS look rather mild and wet
from the middle to end of next week and the ECMWF is slowly turning
in this direction over the last two runs. This combined with
continued expectation of precip may give rise to hydro concerns for
late in the forecast period and certainly merits continued watching.
SMR
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Winter Storm Warning from noon today to midnight PST Friday
night for Cascades of Pierce and Lewis Counties-Cascades of
Snohomish and King Counties.
Winter Storm Warning until midnight PST Friday night for
Cascades of Whatcom and Skagit Counties.
Winter Weather Advisory from noon today to 6 PM PST Friday for
Olympics.
PZ...Small Craft Advisory until 1 PM PST Friday 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.
Small Craft Advisory until 4 AM PST Friday for Admiralty Inlet-
Coastal Waters From Cape Flattery To James Island Out 10 Nm-
Coastal Waters From James Island To Point Grenville Out 10
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.
Small Craft Advisory until 4 AM PST Friday for West Entrance
U.S. Waters Strait Of Juan De Fuca.
Small Craft Advisory from 1 PM this afternoon to 4 PM PST Friday
for Puget Sound and Hood Canal.
&&
www.weather.gov/seattle
You can see an illustrated version of this discussion at
www.weather.gov/seattle/gafd/latest_webafd.html1 heavy snow. Local standard time, as filed.
Mt Baker NWAC station reported 13 inches snow during 12 hours ending 6 pm Mar 3, 22 inches snow during 24 hours ending 4 am Mar 4, and 34 inches total during the warning period.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2017Every state in 2017This day in weather historyWarnings in Washington, March 2017
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: 677908.