An area of cold low pressure moved in from the Pacific Northwest and then strengthened as it moved East of the Continental Divide. The system had ample moisture and brought heavy snow to many areas. The heaviest snow fell along the East Slopes of the Wind River Range where several areas had over 2 feet with the highest amount of 33 inches at the Townsend Creek SNOTEL. Over a foot of snow also fell across portions of the Bighorn Range, Salt and Wyoming Mountains, Absarokas and Tetons. Across the lower elevations, the highest amounts where around the Riverton and Lander areas where 5 to 10 inches of snow fell, depending on elevation. Between 6 to 12 inches of snow also fell across portions of Johnson County as well as the Jackson Valley. However, effects were much less across the lower elevations. With the high late April sun angle, most major roads in the lower elevations remained largely wet through much of the event. An exception was around Beaver Rim where US 287 was shut down during the height of the storm.

Winter Storm in WIND RIVER BASIN, WYOMING
From 27-APR-17 15:00:00 to 28-APR-17 22:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Heavy snow fell in portions of the Wind River Basin. The highest amounts were above 5500 feet with 9.9 inches of snow measured at WFO Riverton. Across the city of Riverton, there was anywhere from 4 to 8 inches of snow. However, since much of the snow fell during the daytime, there was never the total amounts of snow on the ground. In addition, many of the roads remained mainly wet through much of the event.

Winter Storm in LANDER FOOTHILLS, WYOMING
From 27-APR-17 00:00:00 to 28-APR-17 22:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

The official spotter at the Lander airport measured 7.7 inches of new snow. Snowfall amounts around Lander generally ranged from 2 to 6 inches with higher amounts closer to Sinks Canyon State Park. However, most of the main roads were mainly wet with the high late April sun angle melting the snow on paved surfaces.

Winter Storm in GREEN MOUNTAINS & RATTLESNAKE RANGE, WYOMING
From 27-APR-17 03:00:00 to 28-APR-17 19:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

A NWS Employee measured 8 inches of snow at Beaver Rim. 8 inches of snow also fell in Jeffrey City. During the height of the storm, US 287 was closed between Lander and Muddy Gap.

Winter Storm in NATRONA COUNTY LOWER ELEVATIONS, WYOMING
From 27-APR-17 22:00:00 to 28-APR-17 22:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter measured 7 inches of snow 5 miles south-southwest of Casper, in the foothills of Casper Mountain. Amounts dropped quickly closer to downtown where amounts were generally less than 3 inches.

Winter Storm in SALT RIVER & WYOMING RANGES, WYOMING
From 27-APR-17 03:00:00 to 28-APR-17 05:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SNOTEL

At the Blind Bull SNOTEL, 15 inches of new snow fell. At Commisary Ridge, 21 inches of snow were measured.

Winter Storm in ABSAROKA MOUNTAINS, WYOMING
From 27-APR-17 05:00:00 to 28-APR-17 17:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SNOTEL

Heavy snow fell in some of the higher elevations of the Absaroka Mountains. Some of the higher amounts included 25 inches at the Marquette SNOTEL and 19 inches at the Kirwin SNOTEL.

Winter Storm in BIGHORN MOUNTAINS SOUTHEAST, WYOMING
From 27-APR-17 11:00:00 to 28-APR-17 17:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SNOTEL

Heavy snow fell throughout the eastern slopes of the Bighorn range. Some of the highest amounts included 20 inches at the Little Goose SNOTEL site and 19 inches at the Soldier Park SNOTEL.

Winter Storm in NORTHEAST JOHNSON COUNTY, WYOMING
From 27-APR-17 16:00:00 to 28-APR-17 18:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotters measured anywhere from 3.5 to 13 inches across Northern Johnson County, with the highest amounts in the foothills of the Bighorn range.

Winter Storm in SOUTHEAST JOHNSON COUNTY, WYOMING
From 27-APR-17 17:00:00 to 28-APR-17 18:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Anywhere from 6 to 12 inches of snow was measured across southern Johnson county.

Winter Storm in TETON & GROS VENTRE MOUNTAINS, WYOMING
From 26-APR-17 14:00:00 to 28-APR-17 04:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy snow fell in portions of the Tetons. Some the highest amounts included 23 inches at the Jackson Hole Ski Resort and 29 inches at the Grand Targhee SNOTEL.

Winter Storm in JACKSON HOLE, WYOMING
From 26-APR-17 15:00:00 to 28-APR-17 04:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A CocoRAHS spotter reported 11 inches of snow at Moose. Snowfall amounts across the Jackson Valley were very elevation dependent with the city of Jackson only receiving 1.4 inches of snow since the snow mixed with rain at times.

Winter Storm in WIND RIVER MOUNTAINS EAST, WYOMING
From 27-APR-17 14:00:00 to 29-APR-17 00:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SNOTEL

A favorable moist upslope flow and chilly temperatures brought very heavy snow to the eastern slopes of the Wind River Range. There were several locations with over 2 feet of new snow with Townsend Creek having the most with 33 inches of new snow. A spotter at Atlantic City measured 24.5 inches of new snow. Even a bit lower in elevation, there was 17 inches of snow in Sinks Canyon State Park.