The forcing of a 140 to 150 knot northerly upper level jet combined with an influx of Pacific moisture in a post-frontal environment produces heavy snow over north-central Idaho.
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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.
The forcing of a 140 to 150 knot northerly upper level jet combined with an influx of Pacific moisture in a post-frontal environment produces heavy snow over north-central Idaho.
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 28, 2:25 AM PST, 3 hours 35 minutes earlier.
Area Forecast Discussion
National Weather Service Missoula MT
325 AM MST Mon Jan 28 2013
...OVER A FOOT OF NEW SNOW AT SOME LOCATIONS IN THE BITTERROOT
MOUNTAINS BY WEDNESDAY MORNING...
.DISCUSSION...
The air mass over the northern Rockies remains moist and fairly
unstable this morning as flurries and light snow showers have been
present on radar and area webcams. Expect that to continue today
and increase this evening as a system moves into the region. This
system is supported by a strong jet stream over western Idaho. The
forcing of the jet combined with a very moist airmass and strong
upslope flow in the Clearwater and Bitterroot mountains will make
central Idaho the big winner with around a foot of new snow by
Wednesday morning. Winter Storm Watches have been upgraded to
warnings in Idaho and the Bitterroot mountains due to the high
confidence for this event.
For western Montana and Lemhi county Idaho, the forcing of the jet will
be weaker since it is farther west, but unstable and moist
conditions will still promote snow. Valleys are expected to get 2
to 5 inches of snow by Wednesday morning with more in the
mountains. Wind will also be more of an issue, especially Tuesday
morning. Expect travel difficulties with snow accumulating on
roads and blowing snow restricting visibility. Exposed locations
such as Gilmore Summit in Lemhi county and the mountain passes
will especially be impacted by the wind.
Wednesday the most of the energy with this system will have moved
on leaving moist, unstable northwest flow. Expect decreasing snow
showers and winds on Wednesday and overall improving conditions
for travel.
Thursday into Saturday...A moist and unstable northwest flow
remains over western Montana and north central Idaho. So, will
keep some mention of precipitation in the forecast each day,
mainly over the mountains. Then during the day on Saturday a ridge
of high pressure slides over the region, bringing drier conditions.
&&
.AVIATION...Snow showers will continue today with increasing
clouds causing mountain obscurations and minimal impacts to
terminals. A shortwave embedded in moist, unstable northwest flow
will cause lowering ceilings and light to moderate snowfall across
the northern Rockies this evening and through the night. The
Clearwater and Bitterroot mountains of central Idaho will be
hardest hit several inches of snow due to good upslope flow and
jet support tonight.
&&
.MSO WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY from 5 PM this afternoon to 5 AM MST
Wednesday Butte/Blackfoot Region...Potomac/Seeley Lake
Region.
WINTER STORM WARNING from 5 PM this afternoon to 5 AM MST
Wednesday Bitterroot/Sapphire Mountains.
WINTER WEATHER ADVISORY from 5 PM this afternoon to 5 AM MST
Wednesday Missoula/Bitterroot Valleys.
WINTER WEATHER ADVISORY from 5 PM this afternoon to 5 AM MST
Wednesday Lower Clark Fork Region.
WINTER WEATHER ADVISORY from 5 PM this afternoon to 5 AM MST
Wednesday Flathead/Mission Valleys...Kootenai/Cabinet
Region...West Glacier Region.
ID...WINTER WEATHER ADVISORY from 5 PM this afternoon to 5 AM MST
Wednesday Eastern Lemhi County...Western Lemhi County.
WINTER STORM WARNING from 4 PM this afternoon to 4 AM PST
Wednesday Northern Clearwater Mountains...Southern
Clearwater Mountains.
WINTER STORM WARNING from 4 PM this afternoon to 4 AM PST
Wednesday Lower Hells Canyon/Salmon River Region...
Orofino/Grangeville Region.
&&
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https://www.twitter.com/NWSMissoulaThe national radar mosaic for the moment the first event began.
5 heavy snow, 1 winter storm. Local standard time, as filed.
Twelve inches of snow fell in approximately 24 hours in Weippe, Idaho at 3000 feet.
A COOP observer located at Pierce at 3185 feet reported a 24 hour snowfall total of 8.6 inches.
A COOP observer located one mile WNW of Elk City at 4058 feet, reported 12.5 inches of snow in 24 hours.
A COOP observer from one mile north of Dixie at 5740 feet reported a 24 hour snow total of 8.3 inches.
A spotter located 3 miles northeast of Orofino at 3000 feet reported 12 inches of snow in 24 hours.
The Idaho Transportation Department's weather sensor, Frei Hill which is located 3.2 miles southeast of Ferdinand at 3664 feet, reported snow with wind gusts to 23 mph. It can be inferred that there was blowing snow at temperatures between 28 and 32 degrees F. The sensor reported 0.77 of precipitation which can be converted by approximation to 8 and 10 inches of snow.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Idaho in 2013Every state in 2013This day in weather historyWarnings in Idaho, January 2013
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: 428250, 429075, 429076, 429073, 429072, 429069.