Montana, 2021

Winter Storm in Montana, February 22 to 23, 2021

February 22 to 23, 2021 · NWS MSO · 1 event in 1 county or zone

A cold front brought snow and gusty winds through the early morning hours of the 23rd.

Where it happened

Every event with a place to put it; 1 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
1

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 MSO wrote it up.

A cold front brought snow and gusty winds through the early morning hours of the 23rd.

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 Missoula, MT wrote its last area forecast discussion before the first event at Feb 22, 3:52 AM MST, 1 hour 8 minutes earlier.

Area forecast discussion, Feb 22, 3:52 AM MST, 1 hour 8 minutes before
Area Forecast Discussion
National Weather Service Missoula MT
352 AM MST Mon Feb 22 2021

...DAMAGING WINDS POSSIBLE FOR NW MONTANA THROUGH TONIGHT...
...HEAVY MOUNTAIN SNOW ACROSS NORTHERN ROCKIES THROUGH TONIGHT...

.DISCUSSION...

Intense northwest flow aloft will be present over the Northern
Rockies through late tonight. Strong winds and heavy snow are
expected over high terrain, with high snow levels (6000+ feet)
through early this evening. Damaging winds are anticipated to mix
down to low elevations across northwest Montana this morning and
remain very windy through late this evening. The strong winds at
the ridgetops will mostly maintain dry, downsloping winds within
area valleys and limit precipitation. Temperatures will be quite
mild throughout the day. Later this evening, a powerful cold front
will move across the region from the northwest, further
intensifying surfaces and creating some intense bursts of snow
down to valley elevations. Despite low snow accumulations, the
sudden onset of snow, wind, and rapidly cooling temperatures will
combine for hazardous driving conditions all the way through the
remainder of overnight Monday. By Tuesday morning, a couple feet
snow accumulation is possible over high terrain, while mostly
valley locations remain in the 1+ inch range of accumulation.

Snow showers will linger across the Northern Rockies during
Tuesday daytime, ahead of the next significant shot of snow and
cold from the northwest overnight Tuesday through midday
Wednesday. Flow pattern aloft and orientation of this storm
system suggests that the Idaho Camas Prairie will receive up to
several inches accumulating snow. There will also be healthy snow
accumulations for the Clearwater and Bitterroot Mountain ranges
(and nearby low elevations). Some of north central Idaho snow
activity will bleed over into west central Montana valleys, but
likely accumulating around an inch or less.

Another storm system (taking a very similar path as the Tuesday
night storm) is anticipated to move over the Northern Rockies
Thursday to Saturday. Again, the Idaho Camas Prairie appears to be
in a favorable snow pattern, with at least several inches Friday
overnight through Saturday morning. One key difference from the
Tuesday night storm is that this Friday night storm system may be
able to draw in more cold air. In fact, Saturday daytime
temperatures may be 10+ degrees below the seasonal average across
the region.

The cooldown over the weekend will be fleeting, as the cold
airmass is to be quickly supplanted by surging high pressure early
next week. There seems to be quite a bit of noise in the extended
forecast periods, however most signs point toward a relatively
mild pattern and Pacific Ocean influence across much of the
western US.

&&

.Aviation...

Ridgetop winds 50+ knots will be common across Northern Rockies
air space through 23/1200Z. Northwest Montana, including KGPI,
will be impacted with a lot of low level wind shear. PIREPS this
morning have already reported rough turbulence (presumably
mountain wave activity) and the strong wind shear should continue
through tonight. Terrain obscurations will be common during this
time, particularly along the Montana- Idaho border and along the
Continental Divide north of KBTM. Winds will weaken after
23/1200Z, however mainly terrain based snow shower activity will
remain present throughout Tuesday.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory from 8 PM this evening to 7 AM MST
     Tuesday Missoula/Bitterroot Valleys.

     Winter Weather Advisory until 11 PM MST this evening ABOVE 4000
     FEET for the Lower Clark Fork Region.

     Wind Advisory until 11 AM MST this morning Flathead/Mission
     Valleys.

     Wind Advisory until 5 AM MST early this morning West Glacier
     Region.

     Winter Storm Warning until 5 AM MST Tuesday West Glacier Region.

     High Wind Warning until 11 AM MST this morning Kootenai/Cabinet
     Region.

     Winter Weather Advisory until 11 PM MST this evening
     Bitterroot/Sapphire Mountains.

     Winter Weather Advisory from 8 PM this evening to 7 AM MST
     Tuesday Potomac/Seeley Lake Region.

     Winter Weather Advisory from 8 PM this evening to 7 AM MST
     Tuesday Butte/Blackfoot Region.

ID...Winter Weather Advisory until 10 PM PST this evening Northern
     Clearwater Mountains...Southern Clearwater Mountains.

&&

The radar

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

Open the radar archive at this moment

Event by event

1 winter storm. Local standard time, as filed.

Winter Storm, West Glacier Region

When
February 22, 5:00 AM MST to February 23, 5:00 AM MST
Where
West Glacier Region forecast zone
Reported by
Department of Highways
Coordinates
47.971, -114.069 (the zone’s center; the record gives no point)

Two distinct periods of wind and snow occurred, early on the 22nd then again the evening of the 22nd into the early morning hours of the 23rd. Fifty mile per hour wind gusts and snowfall rates of 1-2 inches per hour caused periods of severe driving conditions with chains required from near Essex to Marias Pass on US Highway 2.

What these are

Winter Storm
A storm that brought snow, sleet or freezing rain at warning levels, usually over several hours or days.

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

The same day elsewhere

More

Every storm in Montana in 2021Every state in 2021This day in weather historyWarnings in Montana, February 2021

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: 937905.