The seasons first, widespread winter storm occurred across most of the Billings Forecast Area from February 5th through February 7th. This was also the first and only arctic airmass of the season that impacted the Billings Forecast Area.
Every event with a place to put it; 20 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
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 BYZ wrote it up.
The seasons first, widespread winter storm occurred across most of the Billings Forecast Area from February 5th through February 7th. This was also the first and only arctic airmass of the season that impacted the Billings Forecast Area.
An arctic front blasted through the area on the 5th. Following the front, a moist Pacific flow aloft moved over this arctic airmass which resulted in a prolonged period of heavy snow. Many areas received 8 to 12 inches of snow with some locations reporting well over a foot of snow. After the snow ended and skies cleared, overnight lows of -20F to -40F were common. Many areas stayed below zero for 7 consecutive days.
Major impacts occurred with this storm as warm roads initially melted the snow. These wet roads then quickly froze resulting in icy and hazardous driving conditions. As a result, many accidents occurred across the area. In addition to the snow, strong winds resulted in blowing and drifting snow, as well as significantly reduced visibilities. US-191 was closed near Harlowton due to severe driving conditions as visibilities were a half mile in snow with wind gusts to 43 mph.
Two major crashes occurred on I-90 near Park City just a day apart. The first incident occurred on Saturday the 6th and was a 20-vehicle pileup on the eastbound lanes of I-90. Responders were dealing with a semi stuck in the median when another semi traveling east failed to slow down and yield to road signage. That semi nearly struck a Stillwater County deputy before jackknifing and causing the pileup of vehicles behind it. The Montana Highway Patrol reported only minor injuries with this incident. Another major crash occurred on Sunday the 7th. A pickup truck was hauling a camper that jackknifed. A second pickup truck hauling a camper then crashed into the jackknifed pickup. Shortly after the initial crash, multiple semis crashed into each other as they tried to slow down on an icy bridge deck ahead of the pickup trucks. In one instance, a semi collided with the cab of another semi that was sandwiched in the middle of everything. The driver of the semi that was struck had to be extricated from the vehicle. All five semis were disabled by the crash and two of them caught fire. Just east of this crash, two other semis crashed, including one that went into the median.
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 Billings, MT wrote its last area forecast discussion before the first event at Feb 4, 2:53 PM MST, 2 hours 7 minutes earlier.
Area Forecast Discussion
National Weather Service Billings MT
253 PM MST Thu Feb 4 2021
.DISCUSSION...
Tonight through Friday Night...
Intense winter weather is on our door step. Please be prepared
for significant snowfall and the coldest air yet of the winter
over the next several days. Travel conditions will be very poor.
Several winter weather highlights have been issued.
Satellite imagery shows moist northwest flow from northwest Canada
to our region, with strong ridging over the eastern Pacific.
Taking a broader view, there is an interesting tap of tropic
moisture from near Hawaii to the north Pacific. This enhanced
moisture feed is an important aspect of the upcoming significant
snowfall. Currently, there are some shallow/light snow showers N-E
of Billings along an axis of greater instability. Westerly winds
have gusted 40-50 mph at Big Timber, Livingston and Harlowton
today. These winds should decrease gradually late tonight. Looking
upstream, arctic front appears to have just reached Calgary.
North of this front temps are in the single digits above and below
zero. This is the air mass that will be advecting into eastern MT
late tonight and tomorrow.
For tonight, models continue to paint a region of enhanced snow
showers along an axis of 850mb convergence east of Billings
tonight, which will be further aided by upslope NW winds. This
looks to produce an inch or two over the higher terrain.
Downslope winds will prevail over the west, but snow will become
heavier over the mountains as Canadian shortwave approaches.
Larger impacts begin tomorrow as the cold front moves into our cwa
and overrunning snowfall becomes widespread over our west/central
parts. Eastern zones will be drier tomorrow. Foothills locations
from Livingston to Red Lodge will likely hold off on accumulating
snowfall until the boundary backs all the way there, and for this
reason have continued with a Winter Storm Watch. Periods of snow
should arrive there by tomorrow afternoon and continue off and on
through the weekend, downslope permitting.
Areas from Harlowton through Billings to Sheridan will see
accumulating snowfall by daybreak tomorrow, and this will continue
through the day and Friday night as a series of shortwaves drop
thru the NW flow aloft. Temps will reach their highs very early in
the morning, then drop w/ the backdoor cold advection.
For Billings, expect snow to begin around 5 am (definitely before
sunrise)...so be ready for deteriorating travel conditions for
your morning commute. Don't be surprised if you see 5-6" of snow
by late Friday night.
JKL
Saturday through Thursday...
Cold air in place over the region and a moist northwest flow will
keep overrunning precipitation over the area Saturday and Sunday.
There may be a brief lull in snow over portions of the area for a
time on Saturday, before another reinforcing shot of cold air
from the north/northeast drops in Saturday night and Sunday.
Upslope flow will increase, and in turn, so will the snow.
Snowfall totals from Friday through Sunday will range from 1 to 2
feet over the mountains, to 6 to 12 inches along the foothills and
out onto the plains. Lower totals are expected near the Dakotas
border. Various winter weather highlites cover this well.
Periods of light snow will linger over the area for Monday and
Tuesday, and perhaps into Wednesday as moisture continues to move
over the cold air that will remain in place. Given the cold
airmass, snow will be very fine, and will have a hard time
amounting to much by the time Monday and Tuesday rolls around. The
second half of the coming week becomes uncertain as there are
indications that the cold air could remain over the region, while
other signs point to a slow warming trend with downslope flow
developing, which would increase winds along the western
foothills and cause blowing snow concerns.
High temperatures are forecast to range from the single digits to
teens most places Saturday, cooling to the single digits to around
zero Sunday. Highs look to range from the single digits above and
below zero Monday through Wednesday, and possibly extending into
Thursday. Low temperatures most nights will range from the single
digits to teens below zero. Along with the coldest temperatures of
the winter, wind chill values will be well below zero as well. STP
&&
.AVIATION...
Expect scattered snow showers w/ local MVFR/IFR flight conditions
tonight. Westerly wind gusts of 30-40 knots will continue along
the western foothills (KLVM/K6S0/KHWQ) thru the evening, then
decrease to 15-25 knots overnight into early Friday.
On Friday, snow will become widespread from KBIL-KSHR westward as
a cold front drops out of Canada. Look for MVFR/IFR to local LIFR
tomorrow. This will signal the beginning of an prolonged period
of poor flying weather through the weekend.
Mountains will be mostly obscured tonight and Friday.
JKL
&&
.PRELIMINARY POINT TEMP/POPS...
Fri Sat Sun Mon Tue Wed Thu
-----------------------------------------------------------
BIL 024/027 005/015 000/004 912/902 913/002 913/010 907/013
29/S 96/S 87/S 32/S 21/B 11/B 00/B
LVM 028/033 010/025 008/014 907/006 910/005 905/014 000/021
57/S 66/S 76/S 33/S 22/S 11/B 11/B
HDN 020/027 005/018 000/006 912/000 915/001 919/010 912/013
49/S 96/S 87/S 32/S 21/B 11/B 00/B
MLS 012/020 903/011 906/003 914/901 916/001 917/005 912/008
41/E 73/S 74/S 22/S 11/B 10/B 00/B
4BQ 018/025 002/014 002/007 912/002 914/002 915/009 910/011
62/S 73/S 74/S 22/S 21/B 10/B 00/B
BHK 009/018 908/007 907/003 914/000 916/003 917/006 912/009
31/B 31/E 53/S 12/S 11/B 10/B 00/B
SHR 022/030 007/019 004/011 910/003 912/004 913/013 909/016
69/S 86/S 66/S 32/S 22/S 11/B 00/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Winter Storm Warning in effect from 3 AM Friday to 5 PM MST
Sunday FOR ZONES
29-34-42-57-63-138-141-169-170-172-173-228-235.
Winter Weather Advisory in effect from 6 PM this evening to 5
PM MST Friday FOR ZONES 30-31-36-58.
Winter Storm Watch in effect from Friday afternoon through
Sunday afternoon FOR ZONES 30-31-36-58.
Winter Storm Watch in effect from late tonight through Sunday
afternoon FOR ZONES 40-56-64>66-139.
Winter Storm Warning in effect until 5 PM MST Sunday FOR
ZONES 67-68-171.
WY...Winter Storm Warning in effect from 3 AM Friday to 5 PM MST
Sunday FOR ZONE 199.
Winter Storm Warning in effect until 5 PM MST Sunday FOR ZONE
198.
&&
weather.gov/billingsPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BILLINGS MT
1213 PM MST THU FEB 04 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0700 AM SNOW 13 ESE SHERIDAN 44.72N 106.72W
02/04/2021 M4.0 INCH SHERIDAN WY COCORAHS
0700 AM SNOW 19 NNW BROADUS 45.67N 105.62W
02/04/2021 M3.0 INCH POWDER RIVER MT COCORAHS
&&
ARTHURPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BILLINGS MT
446 PM MST THU FEB 04 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0400 PM SNOW 18 SW FISHTAIL 45.24N 109.73W
02/04/2021 M1.0 INCH STILLWATER MT CO-OP OBSERVER
&&
TWHThe national radar mosaic for the moment the first event began.
20 winter storm. Local standard time, as filed.
Snowfall around 12 inches occurred over the mountains.
The mountains around Livingston and Red Lodge received 12 to 18 inches of snow.
Snowfall of 7 to 10 inches was reported across the Pompeys Pillar area.
Snowfall of 7 to 11 inches occurred from Fort Smith to Lame Deer.
Busby and Hardin both received 6 to 10 inches of snow.
The Roundup area received 8 inches of snow.
Snowfall of 6 to 10 inches was widespread across the area.
Ryegate received 12 to 14 inches of snow.
Snowfall of 12 inches was reported across the Melville area.
Snowfall of 8 to 12 inches was reported across the Joliet, Fromberg and Bridger areas.
Snowfall of 11 inches was reported in the Big Timber area.
U.S 191 was closed due to severe driving conditions.
U.S 191 from Harlowton north was closed due to severe conditions.
The Livingston area received 9 to 17 inches of snow.
The Big Horn Canyon received 6 inches of snow.
Red Lodge received 10 inches of snow.
The Billings area received 8 to 10 inches of snow. Multiple accidents were reported.
Reed Point and Fishtail received 12 inches of snow.
Snowfall of 10 inches was reported across the Bridger area.
Snowfall of 6 inches was reported across the Lame Deer area.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2021Every state in 2021This day in weather historyWarnings in Montana, February 2021
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: 942221, 942222, 942207, 942215, 942217, 942220, 942219, 942218, 942208, 942209, 942213, 942216, 942206, 942203, 942210, 942204, 942205, 942202, 942201, 942200.