A late season, quick hitting heavy snow from a digging low pressure system in the lee of the Rockies produced widespread heavy snow mainly in the evening and overnight hours across southeastern Wyoming. By sunlight on the 16th, many towns and communities had received snow upwards of six inches and more.
Every event with a place to put it; 11 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 CYS wrote it up.
A late season, quick hitting heavy snow from a digging low pressure system in the lee of the Rockies produced widespread heavy snow mainly in the evening and overnight hours across southeastern Wyoming. By sunlight on the 16th, many towns and communities had received snow upwards of six inches and more. The higher terrain areas of the Sierra Madres, Snowy and South Laramie Ranges measured well over a foot of snow.
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 Cheyenne, WY wrote its last area forecast discussion before the first event at Apr 15, 4:02 AM MST, 58 minutes earlier.
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</html>Hazardous Weather Outlook National Weather Service Cheyenne WY 513 AM MDT Wed Apr 15 2020 WYZ112-114-161200- Sierra Madre Range-Snowy Range- 513 AM MDT Wed Apr 15 2020 This hazardous weather outlook is for portions of south central Wyoming. .DAY ONE...TODAY AND TONIGHT Winter Storm Warning in effect from 6 AM MDT Wednesday through 6 AM MDT Friday for heavy snowfall accumulation especially across the higher elevations. Outdoor recreationists should exercise caution during the snowfall event. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY Snow showers will wind down Thursday night into Friday morning. Hazardous weather is not expected over the weekend. .Spotter information statement... Spotters are encouraged to report their morning snowfall totals to the Cheyenne, Wyoming National Weather Service. NEZ019>021-054-055-WYZ101>110-116>119-161200- Scotts Bluff County-Banner County-Morrill-Kimball County-Cheyenne- Converse County Lower Elevations-Niobrara County- North Laramie Range-Ferris/Seminoe/Shirley Mountains- Shirley Basin-Central Laramie Range and Southwest Platte County- East Platte County-Goshen County-Central Carbon County- North Snowy Range Foothills-South Laramie Range- South Laramie Range Foothills-Central Laramie County- East Laramie County- 513 AM MDT Wed Apr 15 2020 This hazardous weather outlook is for portions of panhandle Nebraska...western Nebraska...east central Wyoming...south central Wyoming and southeast Wyoming. .DAY ONE...TODAY AND TONIGHT Winter Storm Warning for heavy snowfall accumulation likely Wednesday night through Thursday afternoon. Prepare for possible travel delays including slick to snow-covered roadways and periods of limited to low visibility. Warning in effect from 6 PM MDT Wednesday through 6 PM MDT Thursday. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY Snow showers will wind down Thursday night into Friday morning. Hazardous weather is not expected over the weekend. .Spotter information statement... NEZ002-003-095-096-WYZ111-113-115-161200- Dawes-Box Butte-North Sioux-South Sioux-Southwest Carbon County- Upper North Platte River Basin-Laramie Valley- 513 AM MDT Wed Apr 15 2020 This hazardous weather outlook is for portions of western Nebraska...south central Wyoming and southeast Wyoming. .DAY ONE...TODAY AND TONIGHT Light to moderate snowfall Wednesday evening through Thursday afternoon will create travel impacts and periods of low visibility. A Winter Weather Advisory is in effect from 6 PM MDT Wednesday to 6 PM MDT Thursday .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY Snow showers should wind end Thursday evening. Hazardous weather is not expected over the weekend. .Spotter information statement... Spotters are encouraged to prepare gauges and snow boards for upcoming winter storm precipitation measurement.
The national radar mosaic for the moment the first event began.
11 heavy snow. Local standard time, as filed.
Sandstone Ranger Station sensor at an elevation of 8150 feet measured a snow water equivalent of 2.0 inches and applying a ratio of 15 to 1 produced an estimated total snowfall of 30.0 inches.
Cinnabar Park sensor at an elevation of 9574 feet measured a snow water equivalent of 1.6 inches and applying a 15 to 1 ration produced an estimated snowfall of 24.0 inches.
Observer in Horse Creek measured a morning snowfall amount on the 16th of 6.0 inches.
Crow Creek sensor at an elevation of 8330 feet measured a snow water equivalent of 1.2 inches and applying a fifteen to one ratio gave an estimated snowfall total of 18.0 inches. A CoCoRaHS observer three miles southeast of Buford measured 7.0 inches the morning of the 16th.
Observer located seven miles south-southeast of Yoder measured a total snowfall of 8.1 inches.
Sage Creek Basin sensor at an elevation of 7850 feet measured a snow water equivalent of 0.7 inches. Applying a snow to liquid ration of 12 to 1 gave an estimated snowfall total of 8.4 inches.
Observer located eight miles west of Chugwater measured a total snowfall of 7.0 inches.
Observer located six miles east-southeast of North Cheyenne measured a total snowfall amount of 9.9 inches.
Observer in downtown Wheatland measured a total snowfall of 6.0 inches.
Observer located seven miles east of Woods Landing measured 10.0 inches of snowfall shortly after 2 AM MST on the 16th. A CoCoRaHS observer east-southeast of Laramie measured just over 6 inches of snow as well.
Observer located in Elk Mountain measured a total snowfall of 8.0 inches.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2020Every state in 2020This day in weather historyWarnings in Wyoming, April 2020
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 2026-10-01. Each event’s entry at NCEI: 880147, 880148, 880144, 880145, 880137, 880138, 880139, 880140, 880141, 880142, 880143.