Freezing rain in Lemhi county caused some road closures and increased avalanche danger over highway 93. Black ice was also being reported in road reports over highway 93.
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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.
Freezing rain in Lemhi county caused some road closures and increased avalanche danger over highway 93. Black ice was also being reported in road reports over highway 93.
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 Jan 8, 2:50 PM MST, 2 hours 10 minutes earlier.
Area Forecast Discussion
National Weather Service Missoula MT
250 PM MST Sun Jan 8 2017
...FREEZING RAIN AND SNOW FORECAST FOR VALLEYS...
.DISCUSSION... A wintry mix of precipitation is on the way for
this evening through Monday.
Central Idaho: In Central Idaho, including Idaho and Clearwater
counties, any freezing rain or sleet is expected to change over to
rain fairly quickly as the area will be windier and will mix out
the cold arctic air.
West Central Montana and Lemhi County Idaho: The arctic air is
entrenched in the valleys and will be much harder to scour out.
Many valley locations remain in the teens for temperatures with
the surrounding mountains around 30F. Additionally, these areas
have been very cold for a long time with ground sub- surface
temperatures in the low teens. As a result, even in areas where
the temperatures may jump well above freezing for a few hours, the
ground will remain so cold that rain will freeze on the roads. The
mountains will mainly see wet snow or some rain which will be
absorbed into the snowpack.
Northwest Montana: The warm air aloft causing the freezing rain
potential will not make it far enough north to affect most of
Northwest Montana for very long, so only very brief wintry mix is
expected there. However, plenty of moisture will still make it
that far north, and as a result the forecast has 5-8 inches of new
snow in the Mission and Flathead valleys. This will likely cause
significant difficulties for snow removal in areas that already
have a deep snowpack on the ground.
Tonight through Monday is the main period for the freezing rain
threat. A cold front will move across the area Monday afternoon
causing a quick change back to snow across the Northern Rockies.
An active weather pattern will be in store for the middle part of
the week. Widespread snow showers are still expected for Tuesday
and the models are showing a weak arctic air mass making its way
across the region. The ECMWF is indicating a surface low passing
across west central Montana and interacting with the arctic
boundary. If this interaction does occur parts of northwest
Montana could experience a burst of snow on Tuesday.
As for the system for Wednesday into Wednesday night, the models are
still forecasting that north central Idaho into southwest Montana
will experience an enhancement in snow. The models diverge on how
much precipitation the area will actually experience. This system
is still expected to bring moderate impacts to the areas,
especially over the mountain passes.
The GFS is showing a second push arctic push Wednesday night into
Thursday while the ECMWF keeps the cold air east of the Divide.
Current thinking is the overall flow pattern would keep the colder
air east of the Northern Rockies, but the situation could change.
For the far extended, little changes were made in the forecast due
to uncertainty in the weather pattern. Friday and/or Saturday
morning's lows could be quite cold, with many valleys once again
dropping to below zero. It all depends on how much cold air makes
it into western Montana and central Idaho earlier in the week.
Going into next weekend, we are expecting another strong surge of
north Pacific moisture moving into the Northern Rockies. This
would surely bring more mountain snow to the region, though the
precipitation type remains uncertain for the valleys.
&&
.AVIATION... Lowering ceilings with an approaching warm front this
afternoon will give way to a wintry mix of precipitation this
evening. Light snow is expected to be the dominate precipitation
type, but there will be occasional freezing rain or drizzle.
Terminal KGPI will see mostly snow, with terminal KBTM receiving
much less precipitation. Terminals KSMN and KMSO are most likely
to see ice impacts throughout the day Monday.
&&
.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory until 5 PM MST Monday Butte/Blackfoot
Region.
Winter Weather Advisory until 5 PM MST Monday
Bitterroot/Sapphire Mountains.
Winter Storm Warning until 5 PM MST Monday Missoula/Bitterroot
Valleys.
Winter Storm Warning until 5 PM MST Monday Lower Clark Fork
Region...Potomac/Seeley Lake Region.
Winter Storm Warning until 5 PM MST Monday Flathead/Mission
Valleys...West Glacier Region.
Winter Storm Warning until 5 PM MST Monday Kootenai/Cabinet
Region.
ID...Winter Storm Warning until 5 PM MST Monday Eastern Lemhi County.
Winter Weather Advisory until 5 PM MST /4 PM PST/ Monday
Northern Clearwater Mountains...Southern Clearwater
Mountains...Western Lemhi County.
Winter Weather Advisory until 10 PM PST this evening Lower Hells
Canyon/Salmon River Region...Orofino/Grangeville Region.
&&The national radar mosaic for the moment the first event began.
1 winter storm. Local standard time, as filed.
Idaho Transportation Department reported slick roads due to freezing rain and black ice. Roads were also closed south of Salmon due to the threat of an avalanche.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Idaho in 2017Every state in 2017This day in weather historyWarnings in Idaho, January 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: 672698.