An early season winter storm impacted the region on the 8th and 9th bringing in mixed precipitation and accumulating snowfall. In addition in the wake of the precipitation, hard freezing temperatures brought an end to the growing season with many locations dropping overnight temperatures into the middle 20s. Cheyenne set a new daily snowfall amount and tied earliest accumulating snowfall.

Heavy Snow in SNOWY RANGE, WYOMING
From 07-SEP-20 23:00:00 to 09-SEP-20 05:00:00 (MST-7)
Reported by: CoCoRaHS

Observer located 1.1 miles north-northeast of Centennial measured a storm snowfall total of 12.3 inches.

Heavy Snow in NORTH SNOWY RANGE FOOTHILLS, WYOMING
From 08-SEP-20 00:52:00 to 09-SEP-20 05:00:00 (MST-7)
Reported by: CoCoRaHS

Observer located about two miles south of Elk Mountain measured a snowfall storm total of 10.3 inches. Other observers in the area also measured heavy snowfall totals over 6.0 inches. Due to near-blizzard-like conditions, Interstate 80 was closed for several hours to allow for plows to clear the road to ensure safe travel conditions.

Heavy Snow in CONVERSE COUNTY LOWER ELEVATIONS, WYOMING
From 07-SEP-20 19:00:00 to 09-SEP-20 00:00:00 (MST-7)
Reported by: CoCoRaHS

Observer located 4.3 miles west-southwest of Douglas measured a storm snowfall total of 10.0 inches of heavy snow.

Heavy Snow in EAST PLATTE COUNTY, WYOMING
From 08-SEP-20 00:03:00 to 08-SEP-20 21:50:00 (MST-7)
Reported by: CoCoRaHS

Observer located roughly twelve miles west-southwest of Glendo measured a total snowfall amount of 6.2 inches.

Heavy Snow in CENTRAL LARAMIE RANGE AND SOUTHWEST PLATTE COUNTY, WYOMING
From 07-SEP-20 23:00:00 to 09-SEP-20 01:00:00 (MST-7)
Reported by: CoCoRaHS

Observer located twenty miles southwest of Wheatland measured a storm total snowfall of 8.3 inches.

Heavy Snow in NIOBRARA COUNTY, WYOMING
From 07-SEP-20 19:14:00 to 08-SEP-20 15:14:00 (MST-7)
Reported by: CoCoRaHS

Observer located roughly a half mile south of Lusk measured a storm total snowfall of 6.0 inches.

Heavy Snow in SOUTH LARAMIE RANGE, WYOMING
From 08-SEP-20 00:00:00 to 09-SEP-20 00:00:00 (MST-7)
Reported by: COOP Observer

Observer located four miles southeast of Buford measured a total storm snowfall total of 8.6 inches.

Winter Storm in CENTRAL CARBON COUNTY, WYOMING
From 08-SEP-20 02:00:00 to 09-SEP-20 00:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Observer located one mile north of Rawlins measured a total storm snowfall amount of 8.2 inches. In addition, high winds were measured by a Wyoming Department of Transportation sensor along Interstate 80 at Walcott Junction between 1:12 AM MST through 2:42 AM MST on the 8th with highest reported wind gust of 58.4 mph, a nearby Union Pacific Railroad sensor had a 60 mph gust at 1:40 AM MST.

Heavy Snow in GOSHEN COUNTY, WYOMING
From 07-SEP-20 21:20:00 to 09-SEP-20 01:00:00 (MST-7)
Reported by: COOP Observer

Observer located twenty-nine miles north of Torrington measured a storm snowfall total of 7.7 inches.

Heavy Snow in NORTH LARAMIE RANGE, WYOMING
From 07-SEP-20 19:00:00 to 09-SEP-20 00:00:00 (MST-7)
Reported by: Public

Observer located twenty miles southwest of Douglas measured at least 12.0 inches of snowfall by the mid-morning hours of the 8th.

Winter Weather in CENTRAL LARAMIE COUNTY, WYOMING
From 08-SEP-20 03:15:00 to 09-SEP-20 00:00:00 (MST-7)
Reported by: Department of Highways

Earliest winter season snowfall was tied at the Cheyenne Airport as periods of initial freezing drizzle and light accumulation blanketed the city. Due to ongoing weather conditions across portions of Interstate 80 between Rawlins and Cheyenne, the roadway was closed to traffic causing a significant loss of commerce as a result. Official total snowfall amount for Cheyenne was 1.1 inches beating the previous record 0.8 inches from 1929.

High Wind in SOUTHWEST CARBON COUNTY, WYOMING
From 07-SEP-20 21:43:00 to 08-SEP-20 10:43:00 (MST-7)
Magnitude: 69.00 MG
Reported by: RAWS

Cow Creek sensor located nineteen miles north of Dixon measured the max reported wind gust.