Winter Storm and Avalanche in Idaho, February 5 to 6, 2020

Name: Winter Storm and Avalanche in Idaho, February 5 to 6, 2020
Start: 2020-02-05T04:00
End: 2020-02-06T21:00
Location: Idaho

February 5 to 6, 2020 · NWS PIH · 15 events in 14 counties and zones

Where it happened

Every event with a place to put it; 15 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

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The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 15

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.

What happened

The episode as NWS PIH wrote it up.

Another strong Pacific storm system brought hazardous travel weather to eastern Idaho in the first week of February. Heavy snow fell along with an extended period of freezing rain in the Lower Snake River Plain overnight on the 5th into the 6th. Several high elevation sites received over a foot of snow with some school closures on the 6th in the region.

What forecasters said that day

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 Pocatello, ID wrote its last area forecast discussion before the first event at Feb 5, 2:33 AM MST, 1 hour 27 minutes earlier.

Area forecast discussion, Feb 5, 2:33 AM MST, 1 hour 27 minutes before

Area Forecast Discussion
National Weather Service Pocatello ID
233 AM MST Wed Feb 5 2020

.SHORT TERM...Today through Friday. Early morning satellite imagery
was showing a broad upper ridge positioned off the west coast with a
stream of Pacific moisture breaking over the ridge and spilling into
SE Idaho. The models have trended toward wider impacts over the last
two days with a persistent stream of Pacific moisture producing
advisory to warning level snowfall across a portion of the CNTRL
mountains and across a larger swath of the ERN and SRN mountains. In
this regard, we have added the southern mountains to the Winter
Weather hazards with this mornings issuance. The impacts here will
be shorter lived and at a higher elevation as warmer temperatures
gradually build into the region from the west Thursday and Friday.
Along with the warmer temperatures, much stronger/advisory-level
winds are expected to develop across the region Thursday into
Friday. Strong winds coupled with fresh snow will likely mean
widespread areas of blowing and drifting snow, especially across the
Snake River Plain. The warmer temperatures across the Eastern Magic
Valley and Lower Snake River Plain may help to mitigate the risk of
blowing snow but locals north and east of Idaho Falls may not fare
as well. More on that as the event draws near. By Friday afternoon,
we should begin to see decreasing snowfall activity as the next
upstream storm system digs SE toward the Seattle area (more on that
below). As previously mentioned, we should see warming temperatures
Thursday and Friday. Huston

.LONG TERM...Friday night through next Wednesday. Early in the long
term portion of the forecast, an area of low pressure is forecast to
be gaining strength across the eastern Pacific, just west of the
Washington Coast. This low is then forecast to carve out a
strengthening low pressure trough across the PacNW and Intermountain
West throughout the weekend, and in the process drive a strong cold
front south across east Idaho on Saturday. The trough is then
forecast to evolve into a northwest flow pattern through the middle
of next week, keeping the door open to cold, Canadian air. Another
low pressure system is then forecast to drop into east Idaho for the
Tuesday into Wednesday timeframe.

Precipitation associated with the weekend low/trough is expected to
enter the east Idaho mountains late Friday night and Saturday
morning, with the possibility of snow showers developing along the
cold front as it slides southward across the Snake Plain later in
the day. Mountain snow showers may linger Saturday night into early
Sunday, especially for higher terrain areas close to the Utah
border. Mainly dry and cold conditions are then expected to settle
into the region (about 10 or so degrees below seasonal averages) for
later Sunday into Monday before snow showers once again arrive in
the Tuesday to Wednesday timeframe. In terms of winds, they're
forecast to be strongest Friday night and Saturday, which may lead
to areas of blowing and drifting snow. After the passage of the cold
front on Saturday, winds should gradually diminish Saturday night,
leaving mainly light winds to close out the weekend into early next
week before winds again increase with the approach of the next
system. Forecast confidence is reasonably high, but there remains
details to be worked out on timing and exact snowfall amounts. AD
&&

.AVIATION...Initial wave of moisture has entered the area from the
northwest in the form of snow showers, bringing IFR conditions to
KPIH and KIDA. Model and observational trends suggest improvement
early this morning before snow showers once again ramp up by mid
morning 14-16Z, with snow shower redevelopment expected at KBYI and
KPIH, likely extending into KIDA as well. KSUN could see some brief
snow shower activity as well, but they will be largely shadowed in
this NW flow regime. Another uptick in snow shower activity is
expected by around 00Z this evening for all but KSUN before
conditions begin to improve very late tonight into Thursday morning,
except for KDIJ where snow showers are favored to linger. CIGs
should bounce around from VFR to IFR, with the most likely period
for widespread IFR conditions from mid to late this morning and
again redeveloping this evening before improving late tonight into
Thursday morning. SW winds across the Snake Plain will largely be in
the 10-20kt range before increasing to the 15-25kt range as we
approach the end of the period/12Z Thursday. AD
&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 11 AM this morning to 5 PM MST Friday
for IDZ060-062-063-065-072.

Winter Storm Warning from 11 AM this morning to 5 PM MST Friday for
IDZ064-066.

Winter Weather Advisory from 11 AM this morning to 9 AM MST Thursday
for IDZ056>058.
&&

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

14 winter storm, 1 avalanche. Local standard time, as filed.

Winter Storm, Caribou Range

When: February 5, 4:00 AM MST to February 6, 8:00 PM MST
Where: Caribou Range forecast zone
Reported by: COOP Observer
Coordinates: 42.815, -111.502 (the zone’s center; the record gives no point)

Very heavy snowfall occurred and caused very hazardous travel. An accident caused US Highway 26 to close for a period of time from Swan Valley to the Wyoming border. 16 inches of snow fell at the Swan Valley COOP site with the following SNOTEL estimates: Giveout 17 inches, Slug Creek Divide 22 inches, and 15 inches in Somsen Ranch.

Winter Storm, Centennial Mountains-Island Park

When: February 5, 4:00 AM MST to February 6, 8:00 PM MST
Where: Centennial Mountains-Island Park forecast zone
Reported by: COOP Observer
Coordinates: 44.091, -111.680 (the zone’s center; the record gives no point)

Very heavy snow once again fell in the Centennial Mountains with 13 inches reported by the Island Park COOP site. SNOTEL estimates were: 16 inches at Island Park, 18 inches at Crab Creek, and 21 inches at White Elephant.

Winter Storm, Lower Snake River Plain

When: February 5, 5:00 AM MST to February 6, 11:00 AM MST
Where: Lower Snake River Plain forecast zone
Reported by: Official NWS Observations
Coordinates: 42.860, -112.488 (the zone’s center; the record gives no point)

During the day on the 5th 2 to 4 inches of snow fell then overnight on the 5th into the morning hours on the 6th a quarter inch of freezing rain accumulated at the Pocatello Regional Airport. Several traffic accidents and slide offs were reported both days. Blackfoot School District 55 closed on the 6th as did Sho-Ban High School and Bingham Academy District 485.

Winter Storm, Bear River Range

When: February 5, 5:00 AM MST to February 6, 9:00 PM MST
Where: Bear River Range forecast zone
Reported by: SNOTEL
Coordinates: 42.412, -111.568 (the zone’s center; the record gives no point)

Very heavy snow fell in the Bear River Range with SNOTEL estimates of 25 inches at Emigrant Summit and 28 inches at Franklin Basin in the 7 thousand foot to 8,200 foot elevation range.

Winter Storm, Beaverhead-Lemhi Highlands

When: February 5, 5:00 AM MST to February 6, 6:00 PM MST
Where: Beaverhead-Lemhi Highlands forecast zone
Reported by: COOP Observer
Coordinates: 44.004, -112.761 (the zone’s center; the record gives no point)

Six inches of snow was reported in Dubois and Small with the storm.

Winter Storm, Big Hole Mountains

When: February 5, 5:00 AM MST to February 6, 7:00 PM MST
Where: Big Hole Mountains forecast zone
Reported by: SNOTEL
Coordinates: 43.644, -111.494 (the zone’s center; the record gives no point)

Very heavy snow fell in the Big Hole's with an estimated 18 inches at Pine Creek Pass which webcams indicated a long period of snow covered roads along US Route 30 through the period.

Winter Storm, Blackfoot Mountains

When: February 5, 5:00 AM MST to February 6, 7:00 PM MST
Where: Blackfoot Mountains forecast zone
Reported by: COOP Observer
Coordinates: 43.125, -111.858 (the zone’s center; the record gives no point)

Nine inches of snow was recorded at the COOP site in Bone and was estimated at the Sheep Mountain SNOTEL site. The North Gem School District 149 was closed due to travel conditions on the 6th.

Winter Storm, Franklin-Eastern Oneida Region

When: February 5, 5:00 AM MST to February 6, 3:00 PM MST
Where: Franklin-Eastern Oneida Region forecast zone
Reported by: COOP Observer
Coordinates: 42.188, -112.176 (the zone’s center; the record gives no point)

Heavy snow caused very difficult travel especially overnight on the 5th and the morning of the 6th. The Oneida School District 351 closed on the 6th due to the conditions. Snow amounts reported by COOP sites were: 5 inches at Malad City, and 5 inches at Preston. The Oxford Springs SNOTEL estimated 11 inches of snow.

Winter Storm, Marsh and Arbon Highlands

When: February 5, 5:00 AM MST to February 6, 3:00 PM MST
Where: Marsh and Arbon Highlands forecast zone
Reported by: COOP Observer
Coordinates: 42.838, -112.256 (the zone’s center; the record gives no point)

Heavy snow fell in the Marsh and Arbon Highlands disrupting travel. 17 inches of snow fell in Inkom in the storm Other amounts were: 7 inches in Downey, 8 inches in McCammon, an estimated 19 inches at the Sedgwick Peak SNOTEL and 7 inches at Wildhorse Divide. The Marsh Valley School District 21 was closed on the 6th due to the hazardous travel and North Gem District 149 was also closed.

Winter Storm, Southern Hills-Albion Mountains

When: February 5, 5:00 AM MST to February 6, 11:00 AM MST
Where: Southern Hills-Albion Mountains forecast zone
Reported by: SNOTEL
Coordinates: 42.284, -113.600 (the zone’s center; the record gives no point)

Very heavy snow fell in the Southern Hills. Amounts estimated at SNOTEL sites were Bostetter Ranger Station 18 inches and Howell Canyon 16 inches.

Winter Storm, Sawtooth-Stanley Basin

When: February 5, 5:00 AM MST to February 6, 3:00 PM MST
Where: Sawtooth-Stanley Basin forecast zone
Reported by: SNOTEL
Coordinates: 43.826, -114.131 (the zone’s center; the record gives no point)

The Vienna Mine SNOTEL estimated 17 inches of snow.

Winter Storm, Teton Valley

When: February 5, 5:00 AM MST to February 6, 12:00 PM MST
Where: Teton Valley forecast zone
Reported by: COOP Observer
Coordinates: 43.924, -111.450 (the zone’s center; the record gives no point)

Eight to 12 inches of snow fell in the Teton Valley with 9 inches reported by the COOP observer in Ashton.

Winter Storm, Upper Snake River Plain

When: February 5, 5:00 AM MST to February 6, 2:00 PM MST
Where: Upper Snake River Plain forecast zone
Reported by: COOP Observer
Coordinates: 43.805, -111.767 (the zone’s center; the record gives no point)

Another round of snow brought hazardous travel conditions to the Upper Snake River Plain again. Amounts for the storm were: 4 inches Idaho Falls, 5 inches Menan, 6 inches Rexburg, 6 inches Rigby, and 11 inches at Saint Anthony and Sugar City.

Winter Storm, Bear Lake Valley

When: February 5, 6:00 AM MST to February 6, 8:00 AM MST
Where: Bear Lake Valley forecast zone
Reported by: COOP Observer
Coordinates: 42.285, -111.330 (the zone’s center; the record gives no point)

Four to 6 inches of snow fell and an avalanche caused the closing of US 89 from Montpelier to Geneva on the 6th.

Avalanche, Bear Lake Valley

When: February 6, 12:00 PM MST to 9:00 PM MST
Where: Bear Lake Valley forecast zone
Reported by: Department of Highways
Coordinates: 42.285, -111.330 (the zone’s center; the record gives no point)

An avalanche closed US Route 89 from Montepelier to Geneva on the afternoon of the 6th to remove snow.

What these are

Winter Storm: A storm that brought snow, sleet or freezing rain at warning levels, usually over several hours or days.
Avalanche: A mass of snow sliding down a mountainside that caused a death, an injury or damage.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Idaho in 2020 Every state in 2020 This day in weather history Warnings in Idaho, February 2020

Sources

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: 878063, 878086, 878028, 878040, 878043, 878046, 878050, 878088, 878103, 878110, 878113, 878126, 878127, 878036, 878014.