Winter Storm and Avalanche in Idaho, February 23 to 28, 2019

Name: Winter Storm and Avalanche in Idaho, February 23 to 28, 2019
Start: 2019-02-23T16:00
End: 2019-02-28T17:00
Location: Idaho

February 23 to 28, 2019 · NWS PIH · 24 events in 22 counties and zones

An extended atmospheric river event occurred for an entire week. Extremely heavy snow fell in the mountains with amounts at SNOTEL sites reaching as high as 5 to 8 feet for the week.

Where it happened

Every event with a place to put it; 22 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

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 24

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.

An extended atmospheric river event occurred for an entire week. Extremely heavy snow fell in the mountains with amounts at SNOTEL sites reaching as high as 5 to 8 feet for the week. Many roads closed through the mountains. Schools closed and some sheet flooding began mainly in Bingham and Minidoka counties where temperatures warmed significantly. Avalanches also occurred in the central mountains with the heavy snowfall accompanied with warmer temperatures. The storm wrapped up a month of record snowfall in the Upper Snake Highlands where the Island Park COOP observer recorded over 100 inches for the month.

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 23, 2:25 PM MST, 1 hour 35 minutes earlier.

Area forecast discussion, Feb 23, 2:25 PM MST, 1 hour 35 minutes before

Area Forecast Discussion
National Weather Service Pocatello ID
225 PM MST Sat Feb 23 2019

.SHORT TERM...Tonight through Tuesday.
While heavy snow associated with the incoming storm has yet to fully
ramp up, enhanced upslope activity noted on radar earlier near and
north of Idaho Falls has yielded totals of 3-7" already today.
With the sun up, impacts to roads south of Rexburg have largely
been limited. We should see this activity begin to pull east of
the Snake Plain, although upslope along the eastern benches of
Idaho Falls and Rexburg will continue and possibly blend into the
increasing snow tonight with the main system.

The circulation associated with the landfalling Pacific PV anomaly
is taking its place and should stagnate in some form through the
middle of the week. As a result, we're beginning to see mid and
low level moisture ramp up on Water Vapor imagery through west
central Idaho. Snow rates that have largely been light through the
west central Idaho mountains will begin to pick up tonight. A
little shortwave disturbance will eject from the parent low and
stream through the Montana Divide area tonight. As a result have
increased PoPs and subsequent qpf/snow totals through the Lost
River Basins and through the Upper Snake Highlands south to Idaho
Falls.

Sunday will be a pretty tough travel day through the area as
temperatures will still be cold enough to support snow pretty much
areawide. More importantly for the Snake Plain, temperatures
remaining cold will keep the antecedent snow to remain easily
lofted. As winds really begin to ramp up tomorrow, areas of blowing
and drifting snow will be common, even where snow is not actively
falling. Blowing snow through the eastern Magic Valley and lower
Snake Plain will be less of a concern Monday and Tuesday as
downslope-aided temperatures climb into the upper 30s and
potentially into the 40s. This should bring the potential for rain
to mix in from Burley through Pocatello and perhaps north to
Blackfoot or Shelley Monday and Tuesday. The fly in the ointment
to high temperatures overachieving will be drying noted in the
lower atmosphere. If precipitation is able to overcome this
downslope drying, the column could collapse and temperatures
could underachieve.

In the mountains, we'll see moderate to heavy snow rates beginning
tonight. This will undoubtedly lead to very difficult traveling
conditions and could bring snow load issues. This is especially true
as we head into Monday and Tuesday with the snow continuing to pile
up and moisture content of that snow increasing.

All told, snow amounts haven't really changed drastically from
previous forecasts besides for becoming a little more detailed.
Still should see several feet of snow in the atmospheric river
targeted locations of the central mountains around Stanley and from
West Yellowstone south through the eastern highlands. Snow amounts
through the Snake Plain and southern highlands will remain the
biggest question mark, but coverage and amounts of snow is coming
into a little clearer picture. Have decided to tack on two more
zones (Shoshone to Carey, and south of Pocatello) to the long
duration Advisories.
TAX

.LONG TERM...Tuesday night through next Saturday. The active pattern
appears poised to continue through the week with a continuation of
many of the issues outlined by the previous shift. To start the
extended period, models do agree that a strong, closed area of low
pressure will be anchored just off of the Washington coast. The
ultimate evolution of this low is the first forecast concern, as
both the GFS and ECMWF allow the low to weaken and evolve into a
trough which eventually passes through our area. The GFS indicates
that this transition will occur some 12-24 hrs faster than the
ECMWF. After the above-mentioned trough passes through the region,
flow transitions more westerly and eventually southwesterly by next
weekend, opening the door for another moisture-laden system. The end
result is a potentially unprecedented period where there is no break
in Precipitation during the entire forecast period for our
Mountains. Now we'll attempt to articulate some day-to-day details:

For Wednesday, the first wave of Precipitation is forecast to be
ongoing across the area. The GFS is significantly colder than the
ECMWF and the national blend of models is leaning in that direction
as well. Didn't totally buy into the colder solution, especially for
the Eastern Magic Valley into the lower Snake Plain where southerly
downslope (warming) wind will be in place. These areas will likely
see mainly Rain during this period, with the transition line to Snow
somewhat in question, i.e. will Idaho Falls remain all Snow or mix
with/change to Rain? Details we'll need to iron out as we get closer
to the event. Precipitation rates slow in the majority of the
guidance for Wednesday night before ramping back up Thursday. This
is when the GFS pushes a strong cold front through the region, while
the ECMWF cools Temperatures down only slightly. Went with a middle
of the road approach here, which does bring a change back to Snow
for the Eastern Magic Valley and Snake Plain Thursday night as
Precipitation rates slacken back off in most guidance. As mentioned,
the next wave of Precipitation arrives Saturday and gradually
expands from south to north across the region. With colder air in
place, this system has the potential to be a significant snow
producer for the entirety of the forecast area before Precipitation
slackens off by late next weekend. Stay tuned as a multitude of
impacts are possible through the week. AD/TAX

&&

.AVIATION...Low confidence TAF forecast through the period. As of
1330PM MST/2030Z IDA was most impacted by SN, with LIFR CIG/VIS in
place. Southerly wind/downsloping was limiting PIH and DIJ to MVFR
while SUN was MVFR as well, waiting for an infusion of moisture and
lift. BYI was VFR. Anticipate slight improvements for IDA, DIJ and
SUN early this evening before conditions deteriorate once again
towards 06Z with an increase in moisture and lift. After a slight
improvement Sunday morning, the main influx of moisture and lift
ultimately moves in towards the end of the TAF period. Southerly
downslope wind should limit deterioration at PIH and BYI to MVFR --
and BYI will likely mix with/change to rain by Sunday afternoon.
Expect mainly IFR at IDA by the end of the TAF period with DIJ
bouncing between MVFR/IFR. Anticipate SUN will crash to near
airfield minima by around 06Z with a decent chance of staying there
through the rest of the period, although brief improvements will be
possible. AD/TAX

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 6 PM this evening to 5 PM MST
Tuesday for IDZ051>053-058-061-067>070.

Winter Storm Warning from 6 PM this evening to 5 PM MST Tuesday
for IDZ060-062>066-071>075.

&&

In the hours before

Local storm report, Feb 23, 11:02 AM MST, 4 hours 58 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE POCATELLO ID
1102 AM MST SAT FEB 23 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1103 AM     SNOW             REXBURG                 43.82N 111.78W
02/23/2019  M3.0 INCH        MADISON            ID   TRAINED SPOTTER

            MEASURED NEW SNOW STARTING FROM EARLY THIS
            MORNING.

&&

TAX

Local storm report, Feb 23, 2:21 PM MST, 1 hour 39 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE POCATELLO ID
221 PM MST SAT FEB 23 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0222 PM     SNOW             REXBURG                 43.83N 111.78W
02/23/2019  E7.0 INCH        MADISON            ID   PUBLIC

            NEW SNOW SINCE VERY EARLY THIS MORNING.

&&

TAX

The radar

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

Open the radar archive at this moment

Event by event

20 winter storm, 2 flood, 2 avalanche. Local standard time, as filed.

Winter Storm, Arco-Mud Lake Desert

When: February 23, 4:00 PM MST to February 27, 8:00 PM MST
Where: Arco-Mud Lake Desert forecast zone
Reported by: Department of Highways
Coordinates: 43.537, -112.374 (the zone’s center; the record gives no point)

Snow and wind caused the closure of US Highway 20 from Carey to Arco and also from Idaho Falls to the US Highway 26 intersection. Snow amounts were not significant and the roads were opened later on in the storm after the closures from the 24th through the 25th. The West Jefferson Schools were closed on the 25th due to the hazardous travel conditions.

Winter Storm, Big Hole Mountains

When: February 23, 4:00 PM MST to February 28, 4:00 PM MST
Where: Big Hole Mountains forecast zone
Reported by: Department of Highways
Coordinates: 43.644, -111.494 (the zone’s center; the record gives no point)

The Pine Creek Pass SNOTEL recorded 21.5 inches of snow during the long event. US Highway 33 was closed from Victor to the Wyoming state line on the 25th and Highway 31 was also closed west of Victor on the 25th.

Winter Storm, Big Lost Highlands-Copper Basin

When: February 23, 4:00 PM MST to February 28, 4:00 PM MST
Where: Big Lost Highlands-Copper Basin forecast zone
Reported by: SNOTEL
Coordinates: 43.792, -113.811 (the zone’s center; the record gives no point)

An extended atmospheric river event the last week of February led to some incredibly high snow totals. Amounts for the week occurred at the following SNOTEL sites: Bear Canyon 54 inches, Garfield Ranger Station 29 inches, Smiley Mountain 69 inches, Stickney Mill 20 inches, and Swede Peak 59 inches.

Winter Storm, Blackfoot Mountains

When: February 23, 4:00 PM MST to February 28, 4:00 PM MST
Where: Blackfoot Mountains forecast zone
Reported by: Department of Highways
Coordinates: 43.125, -111.858 (the zone’s center; the record gives no point)

Snow and high winds created extensive hazardous travel and Idaho Highway 34 was closed from Soda Springs to the Wyoming border on the 25th and 26th. The Bone COOP observer reported 7 inches of snow from the 23rd through the 25th and the Sheep Mountain SNOTEL site recorded 17.5 inches. The Soda Springs, Grace and North Gem schools were closed on the 25th due to hazardous travel conditions.

Winter Storm, Caribou Range

When: February 23, 4:00 PM MST to February 28, 4:00 PM MST
Where: Caribou Range forecast zone
Reported by: Department of Highways
Coordinates: 42.815, -111.502 (the zone’s center; the record gives no point)

Idaho Highway 34 was closed on the 25th and 26th due to snow and high winds from Soda Springs to the Wyoming border. The Slug Creek Divide SNOTEL recorded 9 inches of snow and the Somsen Ranch SNOTEL recorded 10 inches.

Winter Storm, Centennial Mountains-Island Park

When: February 23, 4:00 PM MST to February 28, 4:00 PM MST
Where: Centennial Mountains-Island Park forecast zone
Reported by: Department of Highways
Coordinates: 44.091, -111.680 (the zone’s center; the record gives no point)

A long lasting atmospheric river event caused enormous amounts of snow and combined with wind nearly shut down the Island Park area and Centennial Mountains. The Island Park COOP observer recorded 31.1 inches of snow with the storm and set a February snowfall record at the site with 109.9 inches for the month. The White Elephant SNOTEL site recorded an incredible 90 inches. The Crab Creek and Island Park SNOTEL sites both recorded 23 inches. US Highway 20 was closed from Ashton to the Montana border throughout the storm and Idaho Highway 87 also closed. 12 Semi drivers became stranded at the US 20 and Idaho 87 intersection for multiple days. Fremont County Schools closed for 4 consecutive days due to road conditions as well as road closures from the 25th through the 28th.

Winter Storm, Frank Church Wilderness

When: February 23, 4:00 PM MST to February 28, 4:00 PM MST
Where: Frank Church Wilderness forecast zone
Reported by: SNOTEL
Coordinates: 44.241, -114.282 (the zone’s center; the record gives no point)

An atmospheric river event brought incredibly heavy snow to the Frank Church Wilderness. Although a data sparse region, the Mill Creek Summit SNOTEL site recorded 46.5 inches of snow.

Winter Storm, Lost River Range

When: February 23, 4:00 PM MST to February 28, 4:00 PM MST
Where: Lost River Range forecast zone
Reported by: SNOTEL
Coordinates: 43.982, -113.727 (the zone’s center; the record gives no point)

Extremely heavy snow fell in the Lost Rivers with the following SNOTEL amounts: Hilts Creek 33 inches, Meadow Lake 49 inches and Moonshine 20 inches.

Winter Storm, Lost River Valleys

When: February 23, 4:00 PM MST to February 28, 1:00 AM MST
Where: Lost River Valleys forecast zone
Reported by: Department of Highways
Coordinates: 43.982, -113.727 (the zone’s center; the record gives no point)

Snow and wind caused extremely hazardous travel with US Highway 20 from Carey to Arco closed for several day. Butte County schools were closed on the 25th due to road conditions.

Winter Storm, Marsh and Arbon Highlands

When: February 23, 4:00 PM MST to February 28, 4:00 PM MST
Where: Marsh and Arbon Highlands forecast zone
Reported by: SNOTEL
Coordinates: 42.838, -112.256 (the zone’s center; the record gives no point)

The Sedgwick Peak SNOTEL recorded 16 inches of snow and the Wildhorse Divide SNOTEL recorded 11 inches.

Winter Storm, Sawtooth-Stanley Basin

When: February 23, 4:00 PM MST to February 28, 4:00 PM MST
Where: Sawtooth-Stanley Basin forecast zone
Reported by: COOP Observer
Coordinates: 43.826, -114.131 (the zone’s center; the record gives no point)

A strong Pacific storm system enabled an atmospheric river event to perpetuate for several days and bring extremely heavy snow to the Sawtooth mountain region and the Stanley Basin. The Stanley COOP observer recorded 29 inches of snow with the system while the Vienna Mine SNOTEL in the mountains recorded 79 inches. For a time on the 26th all roads leading into and out of Smiley Creek and Stanley were closed due to a combination of avalanches in the area and drifting snow.

Winter Storm, Shoshone-Lava Beds

When: February 23, 4:00 PM MST to February 28, 5:00 AM MST
Where: Shoshone-Lava Beds forecast zone
Reported by: Department of Highways
Coordinates: 43.089, -113.918 (the zone’s center; the record gives no point)

Snow and blowing snow in the northern part of the zone caused US Highway 20 to close from Carey east through Arco for several days during the extended winter storm.

Winter Storm, Southern Hills-Albion Mountains

When: February 23, 4:00 PM MST to February 25, 4:00 PM 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)

The Bostetter Ranger Station recorded 11.5 inches of snow. The Howell Canyon SNOTEL recorded 31 inches of snow.

Winter Storm, Sun Valley Region

When: February 23, 4:00 PM MST to February 28, 4:00 PM MST
Where: Sun Valley Region forecast zone
Reported by: COOP Observer
Coordinates: 43.826, -114.131 (the zone’s center; the record gives no point)

Heavy snow fell for several days in Sun Valley and the surrounding mountains. An avalanche south of Galena Summit closed highway 75 for several hours on the 26th. The COOP observer at the Ketchum Ranger Station recorded 26 inches of snow with the storm. SNOTEL amounts were: Chocolate Gulch 23 inches, Dollarhide Summit 50 inches, Galena 40 inches, Galena Summit 35 inches, Hyndman 41 inches, and Lost Wood Divide 65 inches.

Winter Storm, Teton Valley

When: February 23, 4:00 PM MST to February 28, 4:00 PM MST
Where: Teton Valley forecast zone
Reported by: Department of Highways
Coordinates: 43.924, -111.450 (the zone’s center; the record gives no point)

Heavy snow and winds caused extensive problems in the Teton Valley. All Fremont County schools were closed from the 25th through the 28th due to road conditions and road closures. The Teton school district was closed on the 25th. Road closures for several days were State Highway 32 from Tetonia to Ashton, State Highway 33 from Newdale to Tetonia, and State highway 47 from Ashton to one mile north of the Warm Springs area.

Winter Storm, Upper Snake River Plain

When: February 23, 4:00 PM MST to February 26, 4:00 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)

Heavy snow fell in parts of the Upper Snake River Plain early in the long winter storm. From the 23rd through the 25th, Idaho Falls recorded 3 inches, Rigby 5 inches, Sugar City 9 inches and Saint Anthony 12 inches. The snow and winds caused the closing of US Highway 20 from Idaho Falls west to Butte City on the 25th impacting the INL commute.

Winter Storm, Wood River Foothills

When: February 23, 4:00 PM MST to February 26, 4:00 PM MST
Where: Wood River Foothills forecast zone
Reported by: COOP Observer
Coordinates: 43.412, -113.980 (the zone’s center; the record gives no point)

Through the 26th, the COOP observer at Picabo recorded 10 inches of snow and the COOP observer at Bellevue recorded 18.2 inches of snow.

Winter Storm, Beaverhead-Lemhi Highlands

When: February 23, 5:00 PM MST to February 28, 4:00 PM MST
Where: Beaverhead-Lemhi Highlands forecast zone
Reported by: Department of Highways
Coordinates: 44.004, -112.761 (the zone’s center; the record gives no point)

Interstate 15 was closed from Dubois to the Montana state line on the 25th through the 26th. Not many reports of snow amounts were received. The Dubois COOP observer reported 2.5 inches but amounts were much heavier northbound on interstate 15.

Winter Storm, Bear River Range

When: February 23, 6:00 PM MST to February 28, 5:00 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)

SNOTEL amounts were 9 inches at Emigrant Summit and 11 inches at Franklin Basin.

Winter Storm, Lower Snake River Plain

When: February 25, 1:00 AM MST to 10:00 AM MST
Where: Lower Snake River Plain forecast zone
Reported by: Tribal Official
Coordinates: 42.860, -112.488 (the zone’s center; the record gives no point)

A Fort Hall tribal government building roof collapsed at 3 am on the 25th. During the month of rapid warm up and cool downs with intermittent heavy snow was thought to be a factor in the collapse. Fortunately no one was in the building at the time of the collapse. Blackfoot and Snake River Schools both closed on the 25th due to expected hazardous travel.

Flood, Bingham

When: February 25, 4:00 AM MST to February 28, 5:00 AM MST
Where: Bingham County, 5 mi SW of Aberdeen to 25 mi E of Ft Hall
Cause: Heavy Rain / Snow Melt
Reported by: Emergency Manager
Coordinates: 42.899, -112.920

A rapid warm up with rain caused extensive snow melt and flooding in Bingham County. 900 West to 100 South starting on Highway 39 to Thomas Road was closed due to high water. Many other roads had running water over them. Many farm fields suffered flooding and standing water on them and one home in Aberdeen became surrounded by water. Overall damage was not significant with the flooding.

Flood, Minidoka

When: February 25, 8:00 AM MST to February 28, 8:00 AM MST
Where: Minidoka County, 4 mi N of Rupert to 4 mi E of Rupert
Cause: Heavy Rain / Snow Melt
Reported by: Emergency Manager
Coordinates: 42.678, -113.670

Warm temperatures and rain associated with a long lasting atmospheric river led to extensive sheet flooding in Minidoka County. Several roads were closed in the Rupert and Paul areas with one gravel road washed away.

Avalanche, Sun Valley Region

When: February 25, 10:30 PM MST to 11:00 PM MST
Where: Sun Valley Region forecast zone
Reported by: Emergency Manager
Coordinates: 43.826, -114.131 (the zone’s center; the record gives no point)

A residence between Ketchum and Hailey was hit by an avalanche at 1056 PM MST on the 25th. The home sustained moderate damage and the debris temporarily halted the flow of the Big Wood River.

Avalanche, Sun Valley Region

When: February 26, 10:00 AM MST to 12:00 PM MST
Where: Sun Valley Region forecast zone
Reported by: Department of Highways
Coordinates: 43.826, -114.131 (the zone’s center; the record gives no point)

An avalanche south of Galena Summit closed Highway 75 from Galena Summit north through Stanley for several hours.

What these are

Winter Storm: A storm that brought snow, sleet or freezing rain at warning levels, usually over several hours or days.
Flood: Flooding that develops more slowly than a flash flood: rivers leaving their banks, or water standing over land for an extended time.
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 2019 Every state in 2019 This day in weather history Warnings in Idaho, February 2019

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: 810594, 810601, 810602, 810610, 810613, 810637, 810649, 810650, 810652, 810662, 810664, 810670, 810671, 810677, 810681, 810683, 810685, 810597, 810596, 810659, 810687, 810644, 810645, 810647.