Heavy snowfall accumulations over a foot were estimated by various SNOTEL sensors across the Sierra Madre and Snowy Ranges in southeastern Wyoming.
Every event with a place to put it; 2 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.
Heavy snowfall accumulations over a foot were estimated by various SNOTEL sensors across the Sierra Madre and Snowy Ranges in southeastern Wyoming.
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 Dec 28, 10:57 AM MST, 3 minutes earlier.
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</html>The national radar mosaic for the moment the first event began.
2 heavy snow. Local standard time, as filed.
Little Snake River sensor at elevation of 8915 feet measured a snow water equivalent of 0.3 inches and applying a ratio of twenty to one gave estimated total of 16.8 inches.
Medicine Bow sensor at elevation of 10510 feet measured a snow water equivalent of 0.1 inches and applying a snow to liquid ratio of twenty to one gave estimated snowfall total of 14.0 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, December 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: 930559, 930560.