Two snowmobilers were caught in an avalanche. One was killed, while the other was partially buried and able to extricate himself.
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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 BOU wrote it up.
Two snowmobilers were caught in an avalanche. One was killed, while the other was partially buried and able to extricate himself. The accident occurred near treeline on a northeast-facing slope at around 11,400 feet. The avalanche was approximately three-quarters of a mile wide and ran about 400 vertical feet. The rider was swept downhill and buried under two feet of snow. Despite efforts from the group of riders and search and rescue, he was not located until the following morning.
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 Denver/Boulder, CO wrote its last area forecast discussion before the first event at Feb 16, 2:23 PM MST, 37 minutes earlier.
Area Forecast Discussion National Weather Service Denver/Boulder CO 223 PM MST Tue Feb 16 2021 .SHORT TERM...(This evening through Wednesday) Issued at 145 PM MST Tue Feb 16 2021 The upper level trough is over western Colorado with increased moisture seen on water vapor pushing in from the northwest. Light snow will increase over the northern mountains through the late afternoon then spread into the central mountains into the early evening hours. There is some weak CAPE associated with the shortwave with only mild QG ascent. Most of the lift will be the product of orographics so expect light snow intensity with amounts still ranging in the 1 to 4 inch range with the slightly higher amounts over the western slopes and higher elevations such as Rabbit Ears pass. At lower elevations winds will gradually switch around to the northwest then north bringing back some of the more shallow, cooler air that was pushed out earlier today. This will also help with some upslope combined with the weak CAPE to bring light snow to portions of the Urban Corridor by the evening hours. We continue to expect little to no accumulation with the snow over the lower elevations with a dusting to a trace possible. Cloud cover will increase with the onset of the shortwave and precipitation but some areas could see some patchy fog by the early morning hours. Temperatures overnight will drop into the teens across the lower elevations with single digits for the far northeastern plains. On Wednesday, the upper trough will deepen and drop south with increasing mid-level moisture embedded in northwest flow. The best QG lift is further south with only weak signals by the afternoon. Model cross-sections show mid-level lapse rates improving through the day with increasing cold air advection behind a slightly weak cold front that will increase upslope north to northeasterly surface winds by the late afternoon. This will help set up the region for some scattered snow showers by the evening and overnight hours on Wednesday. Temperatures for the day will be slightly cooler than Tuesday with influence from the cold front keeping highs in the upper 20s to lower 30s for much of the plains and teens and 20s for the high country. .LONG TERM...(Wednesday night through Tuesday) Issued at 145 PM MST Tue Feb 16 2021 Light snowfall will be ongoing over the Front Range mountains, foothills and adjacent plains on Wednesday evening as a storm system moves across the Rockies and out to the Central Plains. It still looks like the best forcing will miss northeast Colorado to the south, but high mid level lapse rates with cold air advection and weak upslope flow behind the late front should keep snowfall going overnight. Favored areas of the mountains and foothills could see 2 to 4 inches of accumulation, the adjacent plains 1 to 2 inches, and less than an inch elsewhere. Snowfall will gradually decrease overnight and Thursday as subsidence and drying set in behind the trough. Flow aloft will increase Thursday as it turns back to the northwest. It will become breezy in the high country Thursday night as ridgetop winds increase, reaching 50 to 60 mph. Expect blowing snow in the mountains that will reduce visibility, especially at the high passes. More light orographic snowfall is possible in the northern mountains Friday with continued northwest, orographic flow aloft and a broad jet streaming Pacific moisture to the area. The plains will continue to warm and highs should be back in the 40s F, near seasonal normals. Flow aloft will continue to increase late Friday as it turns more zonal under brief ridging ahead of the next trough, which will be coming on shore in the Pacific Northwest. Models are showing up to 70 mph of west-northwest ridgetop flow beneath fairly stable mid level lapse rates around 5 to 6 C/km. There is a weak mountain wave signature in cross sections but right now the situation looks to be a little lacking in stability and wind. It is likely that the high country will see some breezy conditions, blowing snow and possible gusts, and that some downsloping will occur which should warm the foothills a few degrees overnight. That next trough will advance quickly over the weekend and should bring more light snowfall to the area starting Saturday in the mountains, possibly spreading to the plains late Saturday into Sunday. Rain will be possible in some areas of plains due to warm temps, changing to snow in the evening. The trough should exit by late Sunday, and Monday and Tuesday should be mostly dry with more warming for the plains as subsidence sets back in behind the trough. && .AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon) Issued at 145 PM MST Tue Feb 16 2021 ILS and MVFR conditions will be possible at area terminal after 22z with light snow. At this time ceilings are expected to be around 030 then drop to MVFR around 08z. Fog in the vicinity will be possible at KDEN starting around 08 with a chance of it impacting the airport between 08 and 12z Wednesday. Fog is also expected to impact APA during the same timeframe with ceilings at IFR through the period. BJC should stay just south of the aforementioned fog so expect only vicinity impacts. Winds will mainly be from the northwest through the evening with speeds from 8 to 12kts. Winds will switch around to drainage by the evening hours with light winds Wednesday morning. && .BOU WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 6 PM MST this evening for COZ031. && SHORT TERM...Bowen LONG TERM...Direnzo AVIATION...Bowen
Hazardous Weather Outlook National Weather Service Denver/Boulder CO 853 AM MST Tue Feb 16 2021 COZ030>051-171600- Jackson County Below 9000 Feet- West Jackson and West Grand Counties Above 9000 Feet- Grand and Summit Counties Below 9000 Feet- South and East Jackson/Larimer/North and Northeast Grand/ Northwest Boulder Counties Above 9000 Feet- South and Southeast Grand/West Central and Southwest Boulder/ Gilpin/Clear Creek/Summit/North and West Park Counties Above 9000 Feet-Larimer and Boulder Counties Between 6000 and 9000 Feet- Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear Creek/Northeast Park Counties Below 9000 Feet- Central and Southeast Park County- Larimer County Below 6000 Feet/Northwest Weld County- Boulder And Jefferson Counties Below 6000 Feet/West Broomfield County- North Douglas County Below 6000 Feet/Denver/West Adams and Arapahoe Counties/East Broomfield County- Elbert/Central and East Douglas Counties Above 6000 Feet- Northeast Weld County-Central and South Weld County-Morgan County- Central and East Adams and Arapahoe Counties- North and Northeast Elbert County Below 6000 Feet/North Lincoln County- Southeast Elbert County Below 6000 Feet/South Lincoln County- Logan County-Washington County-Sedgwick County-Phillips County- 853 AM MST Tue Feb 16 2021 This hazardous weather outlook is for northeast and north central Colorado. .DAY ONE...Today and Tonight Snow will continue over the mountains today and tonight. New snowfall through tonight for the mountains is expected to be 1 to 4 inches, with slightly higher amounts possible for the mountains north of Rabbit Ears Pass. Scattered snow showers are expected to track across the foothills and nearby plains. Any snow accumulation east of the mountains is expected to be light and less than an inch. Temperatures will vary across the region with highs along the I-25 corridor reaching into the upper 30s with 20s and lower 30s over the northeast. .DAYS TWO THROUGH SEVEN...Wednesday through Monday A storm system will move across the region Wednesday into Thursday and is expected to bring light snowfall to the mountains and plains. More light snowfall is expected in the mountains on Friday, and increasing winds in the high terrain will cause areas of blowing snow which may reduce visibility. There is a better chance of snow over the mountains and northeast plains Saturday into Saturday night. The plains will gradually warm this week, and highs should be back in the 40s F by the weekend. .SPOTTER INFORMATION STATEMENT... Spotter reports will not be needed today or tonight.
The national radar mosaic for the moment the first event began.
1 avalanche. Local standard time, as filed.
A snowmobiler was killed by an avalanche on Ruby Mountain, southeast of Rand.
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| Avalanche, S & E Jackson / Larimer / N & Ne Grand / Nw Boulder Counties Above 9000 Feet | 2021-02-16 | Outside/Open Areas | Direct |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2021Every state in 2021This day in weather historyWarnings in Colorado, February 2021
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 2026-09-24. Each event’s entry at NCEI: 935201.