A warm and moist system caused widespread moderate to heavy snow to fall over north-central Idaho bringing slick conditions and low visibility.
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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 and moist system caused widespread moderate to heavy snow to fall over north-central Idaho bringing slick conditions and low visibility.
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 Dec 14, 3:12 PM MST, 28 minutes earlier.
Area Forecast Discussion
National Weather Service Missoula MT
312 PM MST Wed Dec 14 2016
.DISCUSSION...A stratus layer and high clouds have kept many
locations in western Montana and north-central Idaho from warming
to their potential highs this afternoon. This will help set up the
upcoming winter system tonight. Also, a low stratus deck over
Lookout Pass has been sitting in what we call the dendritic zone
(snow growth zone), because of that, just enough moisture in the
air has created snow only over the pass. This will continue over
the next couple hours, so expect scattered snow and ice as you
reach the pass.
Snow is still on track to move into the region this evening with
main accumulations to be overnight through Thursday morning. The
lack of warming today makes for a really good temperature profile
for snow with the approaching warm front, so we have fairly high
confidence for snow to fall in most places by Thursday morning.
There is a line from Grangeville through Hamilton to Butte where
all the pieces may line up for longer periods of moderate to heavy
snow and thus respectable snow amounts of 5 or more inches of
snow by mid-morning. Those with the most favorable snow production
will see periods of higher snow rates that could add overtime for
snow accumulations. Those that are not in the main focus area
will generally have 3 inches or less. Temperatures are forecast to
warm some during Thursday afternoon and snow accumulations will
taper off.
The arctic is still on track to move into western Montana
Thursday evening and especially overnight. The wind with the
expected cold air may blow snow around and there is the potential
for additional snow with the frontal passage especially in
southwest Montana through Lemhi County Idaho. Cold wind chills of
negative 10 to negative 20 are also likely with the wind Friday
and Friday night.
Another focus area for Thursday night snow is Orofino, the Camas
Prairie, Grangeville, and much of north central Idaho through
Friday morning, so this will likely be another impact period with
cold temperatures and another very favorable snow setup.
With the Arctic airmass in place combined with clearing skies, a
very frigid night is expected across the northern Rockies Friday
night. Temperatures below zero is expected across all of western
Montana with some valleys along the Continental Divide and
northwest Montana may see temperatures of 20 below zero.
A northwesterly flow will setup across the Northern Rockies Monday
behind the retreating arctic, that will keep snow showers in the
forecast for western region. Starting Tuesday, a series of
shortwaves will slide through the northwesterly flow enhancing
the possibility for more significant mountain and mountain pass
snowfall through the rest of the week. The valleys will likely be
shadowed out for the most part, however, we can't rule out periods
of light snow accumulations for western Montana valleys at times
during the week. Keep up on the forecast as we go through the
weekend and get closer to these impact periods.
&&
.AVIATION...A low stratus deck and mid-level clouds have and will
continue to obscure mountain ranges throughout the Northern
Rockies this afternoon and evening. A warm front will be moving
north overnight tonight that will bring widespread light to
moderate snow to the region. Low visibility and ceilings due to
snow will be likely for KSMN starting around 15/0400Z, and
15/0900Z for KMSO and KBTM. Several inches of snow will be
possible for these aviation sites by tomorrow afternoon/evening.
KGPI will see light snow, but not to the degree as areas south of
the I-90 Corridor. Snow intensities will tapper off for most areas
by 16/00Z.
&&
.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory until 11 AM MST Thursday
Bitterroot/Sapphire Mountains.
Winter Weather Advisory until 11 AM MST Thursday Potomac/Seeley
Lake Region.
Winter Weather Advisory until 11 AM MST Friday Butte/Blackfoot
Region.
Winter Weather Advisory until 11 AM MST Thursday Lower Clark
Fork Region.
Winter Weather Advisory until 11 AM MST Thursday
Missoula/Bitterroot Valleys.
ID...Winter Weather Advisory until 10 AM PST Thursday Northern
Clearwater Mountains...Southern Clearwater Mountains.
Winter Weather Advisory until 11 AM MST Thursday Eastern Lemhi
County...Western Lemhi County.
Winter Weather Advisory until 10 AM PST Thursday Lower Hells
Canyon/Salmon River Region...Orofino/Grangeville Region.
&&The national radar mosaic for the moment the first event began.
3 heavy snow, 1 winter storm, 1 winter weather. Local standard time, as filed.
Heavy snow was reported between North Fork and Salmon during the storm where up to 7 inches of snow fell. The Salmon schools were closed due to snowy road conditions.
Moderate to heavy snow created slick conditions with low visibility across the Camas Prairie. Gusty winds between 30 and 40 mph caused blowing and drifting snow on top of the benches above Orofino making some driveways to be impassable. Total snow amounts include 13 on Crow's Bench at Ford's Creek Road, 10 three miles NE Orofino, 8 four miles E Orofino, 7.4 six miles NNW Kamiah, 5 in Orofino, and 4.8 in Ahsahka and Grangeville. Clearwater County schools closed because there was a communications problem due to a power failure that occurred during the storm.
The Idaho Transportation Department reported that 6 to 8 inches of snow fell between Lucille and Riggins. They said that the snow rates were probably 1 to 2 inch per hour rates. Blowing snow from passing vehicles created very low visibility which contributed to the travel danger. The schools in Kooskia closed due to the weather.
Periods of moderate to heavy snow fell with snow amounts including 5 in Powell, 7 at Lolo Pass, and 8 in Dixie.
Moderate to heavy snow caused power issues that affected school communications in Clearwater County resulting in school closures on December 15 and 16. Snowfall amounts generally ranged from 5 to 10 during the event.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Idaho in 2016Every state in 2016This day in weather historyWarnings in Idaho, December 2016
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: 667567, 667557, 667559, 667558, 667563.