A warm front brought heavy mountain snow that caused high impact to area passes.
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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 MSO wrote it up.
A warm front brought heavy mountain snow that caused high impact to area passes.
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 Missoula, MT wrote its last area forecast discussion before the first event at Mar 7, 2:52 PM MST, 4 hours 8 minutes earlier.
Area Forecast Discussion
National Weather Service Missoula MT
252 PM MST Tue Mar 7 2017
.DISCUSSION...Periods of moderate to heavy snow will be on the
increase this evening and is expected to impact area roads through
at least Wednesday morning. The heaviest period of snow will be
overnight tonight along the Montana/Idaho border and over the
Seeley swan range, where snowfall rates of 1 to 2 inch per hour
is possible. Periods of heavy snow will cause hazardous travel
with near zero visibility at times. Winter Storm warnings were
issued for these high impact areas. Additionally, valleys of
northwest Montana will also see periods of steady moderate snow
tonight and they could see widespread 3 to 6 inches of snow.
Slick, snow covered roads will be possible for the Wednesday
morning commute.
Widespread travel impacts from snow, wind, and low visibility will
be present across the Northern Rockies Wednesday evening through
Thursday midday and again Thursday evening through Friday midday.
The Wednesday night snow event will have the greatest impact along
I-90 Superior to Lookout Pass and US Highway 12 Lolo to Powell,
ID. However, impacts will not be exclusive to these areas, as the
remainder of west central Montana and high valleys in western
Montana and Idaho will experience periodic snow on roadways.
The Thursday evening through Friday midday snow event will be
mostly centered over northwest Montana, particularly along Highway
2 east of Kalispell and along Highway 93 Kalispell to Eureka.
Snow, blowing snow, and low visibility will exist over the Glacier
region during this time, with a stalled arctic boundary overhead.
Travel conditions over Marias Pass are likely to be quite brutal.
The Northern Rockies will experience a respite from precipitation
on Saturday as a weak ridge of high pressure moves over the area.
This ridge will be short lived as the active westerly flow
pattern returns by Sunday. The models are hinting at another
significant snow event for the mountains on Sunday with the
valleys experiencing a wintry mix. This active pattern is
anticipated to linger through at least mid next week.
&&
.AVIATION...Snow will be on the increase at area terminals
especially at KGPI and KMSO. KGPI will see steady periods of
moderate snow starting this evening and through the overnight
hours. KMSO should see mainly light snow with brief periods of
moderate snow after 08/0600Z. Main impacts will be low ceilings
and reduced visibilities due to the steady light to moderate snow
tonight. For KBTM and KSMN, light snow showers will be possible,
which could cause reduced visibilities/ceilings at times.
&&
.MSO WATCHES/WARNINGS/ADVISORIES...
MT... Winter Storm Warning until 11 AM MST Wednesday Lower Clark Fork
Region.
Winter Weather Advisory until 11 AM MST Wednesday
Flathead/Mission Valleys.
Winter Storm Watch from Thursday afternoon through Friday
morning Flathead/Mission Valleys...West Glacier Region.
Winter Weather Advisory until 11 AM MST Wednesday West Glacier
Region.
Winter Weather Advisory until 11 AM MST Wednesday
Kootenai/Cabinet Region.
Winter Storm Warning until 11 AM MST Wednesday
Bitterroot/Sapphire Mountains.
Winter Storm Warning until 11 AM MST Wednesday Potomac/Seeley
Lake Region.
Winter Weather Advisory from 8 PM this evening to 11 AM MST
Wednesday Butte/Blackfoot Region.
ID...Winter Weather Advisory until 10 AM PST Wednesday Northern
Clearwater Mountains...Southern Clearwater Mountains.
&&The national radar mosaic for the moment the first event began.
2 heavy snow, 1 winter weather. Local standard time, as filed.
Difficult travel due to heavy snow occurred from Lookout Pass to Haugen along Interstate 90. Montana Department of Transportation listed Taft to Lookout Pass as severe driving conditions between 948 pm on the 7th to 522 am MST on the 8th.
The Lolo Pass Visitor center reported up to 18 inches of snow during the event while Lost Trail Pass saw up to 6 inches.
Snowfall amounts during this storm include: 5 to 8 inches in the Seeley and Swan valleys, 3.3 inches in Condon and 11 inches at the top of Snowbowl Ski Resort. Roads conditions were mainly snow and ice.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2017Every state in 2017This day in weather historyWarnings in Montana, 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: 678333, 678335, 678336.