A large, slow moving low pressure system intensified rapidly as it tracked across the central Rockies between 4/2 and 4/5. This weather system combined with a historically significant amount of moisture from both the Pacific Ocean and Gulf of Mexico to produce extreme snowfall rates across portions of southeast Wyoming. Heavy snow initially developed across Carbon, Albany, Converse, and Niobrara counties during the overnight hours from 4/2 into 4/3, before spreading across the remainder of the High Plains late in the evening on 4/3. Accumulating snowfall persisted across much of the region until mid to late afternoon on 4/4. Total accumulations ranged from 1 to 2 feet for many areas along and north of a line from Rawlins to Wheatland to Lusk, with localized amounts exceeding 2 feet in higher elevation areas. In Carbon County near Rawlins and Elk Mountain, the snow combined with strong wind gusts near 45 MPH to produce periods of blizzard conditions. Significant transportation impacts were reported with extended (36+ hour) closures including both I-80 and I-25 west and north of Cheyenne, respectively.

Winter Storm in NORTH SNOWY RANGE FOOTHILLS, WYOMING
From 03-APR-23 00:00:00 to 04-APR-23 15:00:00 (MST-7)
Reported by: Public

Multiple reports of 6+ inches of snow were received from the North Snowy Range Foothills  area near Elk Mountain. The public estimated up to 2 feet of accumulation near Arlington.

Blizzard in NORTH SNOWY RANGE FOOTHILLS, WYOMING
From 03-APR-23 20:50:00 to 04-APR-23 03:00:00 (MST-7)
Reported by: Department of Highways

Multiple WYDOT sensors along I-80 recorded heavy snow and frequent wind gusts 35-45 MPH reducing visibilities to between 1/8 and 1/4 mile for several hours.

Winter Storm in SIERRA MADRE RANGE, WYOMING
From 02-APR-23 22:00:00 to 04-APR-23 17:00:00 (MST-7)
Reported by: SNOTEL

An estimated 9 to 15 inches of snow fell over the Sierra Madre Range per various SNOTEL observations. The highest amount of 15 inches was recorded at Whiskey Peak (WPKW4), 3 WSW of Hog Park Reservoir, at an elevation of 8950 feet.

Winter Storm in SNOWY RANGE, WYOMING
From 02-APR-23 22:00:00 to 04-APR-23 17:00:00 (MST-7)
Reported by: SNOTEL

An estimated 1 to 2 feet of snow fell over the Snowy Range per various SNOTEL observations. The highest amount of 21.6 inches was recorded at Brooklyn Lake (BKLW4) at an elevation of 10,240 feet.

Winter Weather in LARAMIE VALLEY, WYOMING
From 03-APR-23 20:00:00 to 04-APR-23 15:00:00 (MST-7)
Reported by: Public

The public reported 3 to 6 inches of snow in and around the city of Laramie.

Winter Storm in SOUTH LARAMIE RANGE, WYOMING
From 02-APR-23 22:00:00 to 04-APR-23 17:00:00 (MST-7)
Reported by: SNOTEL

The Crow Creek SNOTEL (CRWW4) in the South Laramie Range at an elevation of 8330 feet recorded an estimated 9.0 inches of snowfall.

Winter Storm in SOUTH LARAMIE RANGE FOOTHILLS, WYOMING
From 02-APR-23 22:00:00 to 04-APR-23 17:00:00 (MST-7)
Reported by: Public

Multiple reports of 6 to 12 inches of snow across the South Laramie Range Foothills. The public reported a maximum total of 13.0 inches 16 miles northwest of Cheyenne.

Winter Weather in CENTRAL LARAMIE COUNTY, WYOMING
From 03-APR-23 20:41:00 to 04-APR-23 15:00:00 (MST-7)
Reported by: Official NWS Observations

Multiple sources reported an average of 3 to 6 inches of snow across central Laramie County. A few locally higher totals near 7 inches were observed around the city of Cheyenne, but local transportation routes were not significantly impacted.

Winter Weather in EAST LARAMIE COUNTY, WYOMING
From 03-APR-23 20:00:00 to 04-APR-23 15:00:00 (MST-7)
Reported by: Public

Multiple sources reported an average of 3 to 6 inches of snow across eastern Laramie County.

Winter Storm in CONVERSE COUNTY LOWER ELEVATIONS, WYOMING
From 03-APR-23 00:00:00 to 04-APR-23 17:00:00 (MST-7)
Reported by: Trained Spotter

Widespread 12+ inch snowfall totals were observed across the lower elevations of Converse County. A maximum total of 23.5 inches was reported by a Trained Spotter located in Douglas.

Winter Storm in NIOBRARA COUNTY, WYOMING
From 03-APR-23 00:00:00 to 04-APR-23 17:00:00 (MST-7)
Reported by: Public

Widespread 20+ inch snowfall totals were observed across Niobrara County. The public reported a maximum total of 30.0 inches in the city of Lusk.

Winter Storm in NORTH LARAMIE RANGE, WYOMING
From 03-APR-23 00:00:00 to 05-APR-23 17:00:00 (MST-7)
Reported by: Trained Spotter

Widespread 18+ inch snowfall totals were observed across the northern Laramie Range, per multiple sources. The public reported a maximum total of 42.0 inches approximately 22 miles south of Glenrock.

Winter Storm in FERRIS/SEMINOE/SHIRLEY MOUNTAINS, WYOMING
From 03-APR-23 00:00:00 to 04-APR-23 15:00:00 (MST-7)
Reported by: Public

Widespread 20+ inch snowfall totals were observed across northern Carbon County. The public reported a maximum total of 24.0 inches 30 miles east of Muddy Gap.

Blizzard in FERRIS/SEMINOE/SHIRLEY MOUNTAINS, WYOMING
From 03-APR-23 22:06:00 to 04-APR-23 01:06:00 (MST-7)
Reported by: Department of Highways

A WYDOT sensor located near the Carbon and Natrona County line recorded 3+ hours of blizzard conditions with wind gusts 35-45 MPH and visibilities as low as 1/8 mile.

Winter Storm in SHIRLEY BASIN, WYOMING
From 03-APR-23 00:00:00 to 04-APR-23 15:00:00 (MST-7)
Reported by: Mesonet

A combination of nearby public reports and the NOHRSC National Snowfall Analysis indicate that 12 to 24 inches of snow fell across the Shirley Basin. Periods of near-blizzard conditions were also observed at Shirley Rim along Wyoming Highway 487.

Winter Storm in CENTRAL LARAMIE RANGE AND SOUTHWEST PLATTE COUNTY, WYOMING
From 03-APR-23 19:00:00 to 04-APR-23 13:00:00 (MST-7)
Reported by: CoCoRaHS

A CoCoRaHS observer located 15 miles northwest of Wheatland measured 9.0 inches of snow in the 24-hour period ending at 8 AM MDT on 4/4.

Winter Storm in EAST PLATTE COUNTY, WYOMING
From 03-APR-23 16:00:00 to 04-APR-23 17:00:00 (MST-7)
Reported by: Public

Multiple public reports of 14-16 inches of snow were received across eastern Platte County.

Winter Storm in GOSHEN COUNTY, WYOMING
From 03-APR-23 18:00:00 to 04-APR-23 17:00:00 (MST-7)
Reported by: Public

Widespread 8+ inch snowfall totals were observed across Goshen County, per multiple sources. The heaviest snow fell in the northern third of the county, where amounts locally exceeded 15 inches. The public reported a maximum total of 20.0 inches approximately 32 miles north of Torrington.

Winter Storm in CENTRAL CARBON COUNTY, WYOMING
From 03-APR-23 00:00:00 to 04-APR-23 15:00:00 (MST-7)
Reported by: COOP Observer

Multiple sources including NWS Cooperative Observers, trained weather spotters, and members of the general public, reported 10 inches of snow in the city of Rawlins.

Blizzard in CENTRAL CARBON COUNTY, WYOMING
From 03-APR-23 21:21:00 to 04-APR-23 05:00:00 (MST-7)
Reported by: ASOS

The Rawlins (KRWL) ASOS indicated periods of 0.50 to 0.25 mile visibility with snow and wind gusts 40-50 MPH for much of the evening and overnight from 4/3 into 4/4, reaching the required 3-hour persistence shortly after midnight.