Snow and sub-zero temperatures blanketed southeastern Wyoming Valentine's Day weekend. Southern mountains and portions out in the high plains measured heavy snowfall coupled then with extreme sub-zero temperatures into the minus teens and twenties for many. Rawlins and Laramie set new daily record low temperatures. With area ranchers in calving season, many had to prepare additional feed and wind breaks to keep herd alive along with snow during portion of the extreme cold.

Extreme Cold/Wind Chill in LARAMIE VALLEY, WYOMING
From 12-FEB-21 18:26:00 to 15-FEB-21 02:58:00 (MST-7)
Reported by: ASOS

Laramie Airport along with Union Pacific Railroad and Wyoming Department of Transportation sensors measured wind chills below minus 30. In addition, Laramie Airport also set a new record low temperature for the fourteenth with minus 17 breaking the previous record of minus 14 set back in 1951. With area ranchers in calving season, many had to prepare additional feed and wind breaks to keep herd alive along with snow during portion of the extreme cold.

Extreme Cold/Wind Chill in EAST LARAMIE COUNTY, WYOMING
From 11-FEB-21 20:32:00 to 15-FEB-21 04:18:00 (MST-7)
Reported by: Department of Highways

Wyoming Department of Transportation near Gun Barrel along United States Highway 85 measured wind chill values below minus 30. With area ranchers in calving season, many had to prepare additional feed and wind breaks to keep herd alive along with heavy snow during portion of the extreme cold.

Extreme Cold/Wind Chill in CENTRAL LARAMIE COUNTY, WYOMING
From 12-FEB-21 02:46:00 to 15-FEB-21 04:06:00 (MST-7)
Reported by: ASOS

Cheyenne Airport along with other Wyoming Department of Transportation sensors measured wind chills below minus 30. With area ranchers in calving season, many had to prepare additional feed and wind breaks to keep herd alive along with snow during portion of the extreme cold.

Extreme Cold/Wind Chill in CONVERSE COUNTY LOWER ELEVATIONS, WYOMING
From 11-FEB-21 09:00:00 to 15-FEB-21 07:15:00 (MST-7)
Reported by: ASOS

Douglas Converse County Airport measured wind chills lower than minus 30. With area ranchers in calving season, many had to prepare additional feed and wind breaks to keep herd alive along with snow during portion of the extreme cold.

Extreme Cold/Wind Chill in NIOBRARA COUNTY, WYOMING
From 11-FEB-21 17:32:00 to 15-FEB-21 02:28:00 (MST-7)
Reported by: Mesonet

Several Union Pacific Railroad sensors measured wind chill values below minus 30. With area ranchers in calving season, many had to prepare additional feed and wind breaks to keep herd alive along with heavy snow during portion of the extreme cold.

Extreme Cold/Wind Chill in NORTH LARAMIE RANGE, WYOMING
From 11-FEB-21 20:44:00 to 14-FEB-21 06:52:00 (MST-7)
Reported by: RAWS

The Dodge Creek and Esterbrook sensors measured wind chill values below minus 30. With area ranchers in calving season, many had to prepare additional feed and wind breaks to keep herd alive along with snow during portion of the extreme cold.

Extreme Cold/Wind Chill in SOUTH LARAMIE RANGE FOOTHILLS, WYOMING
From 12-FEB-21 00:54:00 to 15-FEB-21 04:10:00 (MST-7)
Reported by: Department of Highways

Several Wyoming Department of Transportation sensors along Interstate 80 measured wind chill values below minus 30. With area ranchers in calving season, many had to prepare additional feed and wind breaks to keep herd alive along with snow during portion of the extreme cold.

Extreme Cold/Wind Chill in SOUTH LARAMIE RANGE, WYOMING
From 11-FEB-21 22:10:00 to 14-FEB-21 21:20:00 (MST-7)
Reported by: Department of Highways

Wyoming Department of Transportation and Union Pacific Railroad sensors measured wind chill values below minus 30. With area ranchers in calving season, many had to prepare additional feed and wind breaks to keep herd alive along with snow during portion of the extreme cold.

Heavy Snow in NIOBRARA COUNTY, WYOMING
From 12-FEB-21 21:00:00 to 14-FEB-21 04:00:00 (MST-7)
Reported by: Trained Spotter

Observer located five miles north-northeast of Lusk measured 7.0 inches of snowfall the morning of the 13th.

Extreme Cold/Wind Chill in FERRIS/SEMINOE/SHIRLEY MOUNTAINS, WYOMING
From 11-FEB-21 18:15:00 to 15-FEB-21 01:45:00 (MST-7)
Reported by: Mesonet

Hydrometeorological Automated Data System at Seminoe Dam measured wind chill values below minus 30. With area ranchers in calving season, many had to prepare additional feed and wind breaks to keep herd alive along with snow during portion of the extreme cold.

Extreme Cold/Wind Chill in SHIRLEY BASIN, WYOMING
From 11-FEB-21 19:44:00 to 14-FEB-21 16:52:00 (MST-7)
Reported by: Department of Highways

Wyoming Department of Transportation sensor out by Shirley Rim measured wind chill values below minus 30. With area ranchers in calving season, many had to prepare additional feed and wind breaks to keep herd alive along with snow during portion of the extreme cold.

Extreme Cold/Wind Chill in CENTRAL LARAMIE RANGE AND SOUTHWEST PLATTE COUNTY, WYOMING
From 12-FEB-21 01:10:00 to 15-FEB-21 06:54:00 (MST-7)
Reported by: Department of Highways

Wyoming Department of Transportation sensor along Interstate 25 at Bordeaux measured wind chill values below minus 30. With area ranchers in calving season, many had to prepare additional feed and wind breaks to keep herd alive along with snow during portion of the extreme cold.

Extreme Cold/Wind Chill in EAST PLATTE COUNTY, WYOMING
From 11-FEB-21 18:52:00 to 15-FEB-21 07:26:00 (MST-7)
Reported by: Mesonet

Several sensors including AWOS at Wheatland and Wyoming Department of Transportation sensors measured wind chills below minus 30. With area ranchers in calving season, many had to prepare additional feed and wind breaks to keep herd alive along with heavy snow during portion of the extreme cold.

Heavy Snow in EAST PLATTE COUNTY, WYOMING
From 12-FEB-21 21:00:00 to 14-FEB-21 03:00:00 (MST-7)
Reported by: CoCoRaHS

Observer located roughly five miles south of Guernsey measured a total snowfall of 8.0 inches.

Heavy Snow in GOSHEN COUNTY, WYOMING
From 12-FEB-21 21:00:00 to 14-FEB-21 04:00:00 (MST-7)
Reported by: CoCoRaHS

Multiple observers across Goshen County measured snowfall accumulations varying from 6 to 9.0 inches.

Winter Storm in NORTH SNOWY RANGE FOOTHILLS, WYOMING
From 13-FEB-21 12:00:00 to 14-FEB-21 04:00:00 (MST-7)
Reported by: Department of Highways

Due to heavy snow and blowing snow conditions across Interstate 80, the Wyoming Department of Transportation shut down the interstate to all travel between 10:14 PM MST and reopened the road at 5:09 AM MST with a private-trucking company loss of commerce estimated at around $1 million per hour. Due to blowing snow, snow catchment by area observers were less than heavy snowfall with highest total of 4.6 inches two miles south of Elk Mountain.

Heavy Snow in EAST LARAMIE COUNTY, WYOMING
From 13-FEB-21 12:00:00 to 14-FEB-21 09:00:00 (MST-7)
Reported by: Public

Observer located in Pine Bluffs reported 6.0 inches of snowfall the morning of the 14th.

Extreme Cold/Wind Chill in GOSHEN COUNTY, WYOMING
From 14-FEB-21 17:28:00 to 15-FEB-21 05:20:00 (MST-7)
Reported by: ASOS

Torrington Municipal Airport measured wind chill values below minus 30. With area ranchers in calving season, many had to prepare additional feed and wind breaks to keep herd alive along with heavy snow during portion of the extreme cold.

Extreme Cold/Wind Chill in SOUTHWEST CARBON COUNTY, WYOMING
From 13-FEB-21 21:43:00 to 14-FEB-21 08:35:00 (MST-7)
Reported by: RAWS

Cow Creek sensor measured wind chill values below minus 30. With area ranchers in calving season, many had to prepare additional feed and wind breaks to keep herd alive along with snow during portion of the extreme cold.

Extreme Cold/Wind Chill in NORTH SNOWY RANGE FOOTHILLS, WYOMING
From 12-FEB-21 21:38:00 to 14-FEB-21 13:32:00 (MST-7)
Reported by: Department of Highways

Wyoming Department of Transportation sensors along Interstate 80 measured wind chill values below minus 30. With area ranchers in calving season, many had to prepare additional feed and wind breaks to keep herd alive along with a winter storm during portion of the extreme cold.

Heavy Snow in SNOWY RANGE, WYOMING
From 11-FEB-21 05:00:00 to 14-FEB-21 09:00:00 (MST-7)
Reported by: SNOTEL

North French Creek sensor at elevation of 10,130 feet measured a snow water equivalent 1.80 inches and applying to a snow to liquid ratio of 20 to 1 gave an estimated snowfall total of 36.0 inches.

Heavy Snow in SIERRA MADRE RANGE, WYOMING
From 11-FEB-21 05:00:00 to 14-FEB-21 10:00:00 (MST-7)
Reported by: SNOTEL

Blackhall Mountain sensor at elevation of 9820 feet measured a snow water equivalent of 2.50 inches and applying a snow to liquid ratio of 15 to 1 gave an estimated snowfall total of 37.5 inches.

Extreme Cold/Wind Chill in CENTRAL CARBON COUNTY, WYOMING
From 13-FEB-21 16:52:00 to 14-FEB-21 10:22:00 (MST-7)
Reported by: ASOS

Rawlins Municipal Airport along with many other Union Pacific Railroad and Wyoming Department of Transportation sensors measured wind chill values below minus 30. Rawlins in addition set a new record low temperature on the fourteenth with minus 14 breaking the previous record of minus 8 in 1964. With area ranchers in calving season, many had to prepare additional feed and wind breaks to keep herd alive along with snow during portion of the extreme cold.

Extreme Cold/Wind Chill in UPPER NORTH PLATTE RIVER BASIN, WYOMING
From 13-FEB-21 21:38:00 to 14-FEB-21 09:32:00 (MST-7)
Reported by: Department of Highways

Wyoming Department of Transportation sensor at Skyline measured wind chill values below minus 30. With area ranchers in calving season, many had to prepare additional feed and wind breaks to keep herd alive along with snow during portion of the extreme cold.

Extreme Cold/Wind Chill in SNOWY RANGE, WYOMING
From 13-FEB-21 20:05:00 to 14-FEB-21 07:52:00 (MST-7)
Reported by: RAWS

Sawmill Park sensor at elevation of 9734 feet measured wind chill values below minus 30. With area ranchers in calving season, many had to prepare additional feed and wind breaks to keep herd alive along with heavy snow during portion of the extreme cold.