A storm system brought a brief period of light to moderate snowfall to areas in and near the Front Range Foothills and I-25 Corridor. 5 inches at the National Weather Service Office in Boulder, 6 inches near Marshall, Nederland and Genesee, with 2 to 5 inches elsewhere.
Every event with a place to put it; 5 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 BOU wrote it up.
A storm system brought a brief period of light to moderate snowfall to areas in and near the Front Range Foothills and I-25 Corridor. Storm totals included: 6.5 inches at the National Weather Service Office in Boulder, 6 inches near Marshall, Nederland and Genesee, with 2 to 5 inches elsewhere.
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 10, 3:06 PM MST, 54 minutes earlier.
Area Forecast Discussion National Weather Service Denver/Boulder CO 306 PM MST Wed Feb 10 2021 .SHORT TERM...(This evening through Thursday) Issued at 240 PM MST Wed Feb 10 2021 Westerly flow aloft will continue through the night tonight and into the day tomorrow with shallow cold air and upslope flow across the plains. This westerly flow has a little bit of moisture with it that will continue to fall across the western slopes of the mountains tonight and tomorrow. The mountain ridges may see another couple inches of snow but lower elevations should just see flurries. The decent flow aloft will also allow for gusts to reach up to 50 mph across the mountain ridges tonight with blowing snow possible over some of the mountain passes. Otherwise, there will be near normal to slightly above normal temperatures in the mountains. The plains and urban corridor will see very similar conditions tonight and tomorrow as they did today. This is the case where a persistence forecast appears to be the best option. A fog/stratus deck will move westward later this evening eventually making it back to the Denver metro after midnight. This fog/stratus deck will continue into the morning hours with flurries and/or light snow showers possible mainly near and downstream of refineries. A jet streak will move across far northern Colorado during the late afternoon which may provide some lift for snow showers to begin across the Cheyenne Ridge. Otherwise, a cold morning is in store with a quick increase in temperatures around midday when the sun comes out. .LONG TERM...(Thursday night through Wednesday) Issued at 240 PM MST Wed Feb 10 2021 Winter pattern entrenched across northeast Colorado through this weekend with temperatures well below normal and continued chances of flurries and light snow. A persistence forecast along with continued trending of downward temperatures through the weekend is the way to go, while looks like Saturday night through Sunday night will see some of the coldest temperatures of the year (potential for record setting low temperatures.) Best chance of widespread accumulating snow will be Saturday night and Sunday. For Thursday night and Friday, a reinforcing shot of colder air and a better chance for light snow as an upper wave slides across the area on Friday with weak QG ascent. However with low levels already moist and shallow upslope flow, shouldn't take much for light snow/flurries to develop. Could see some accumulating light snow especially across the far northeast plains. Have already dropped temperatures a few degrees further during these periods. Snow will also be increasing in the mountains in the Thursday night and Friday with deepening moisture. Appears zone 31 and the Rabbit Ears Pass region will have the best chance for the heavier snow and winter weather advisories may eventually be needed. For the weekend, a bit of a break early in the day on Saturday and then the next stronger upper trof will drop in across Colorado with some moderate QG ascent for Saturday night and early Sunday. This looks like the period with the best chance for widespread snowfall and the coldest temperatures. Readings on Sunday will only be in the single digits to around zero and well below zero for most locations over the plains Sunday night into early Monday. Looks like some slow moderation in temperatures and improving conditions early next week. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 240 PM MST Wed Feb 10 2021 Light winds with VFR conditions will continue through the evening. Overnight, another stratus/fog deck appears likely to move back in with similar conditions to today (Wednesday) with IFR/LIFR ceilings and visibility. The forecast challenges will be how low the visibility gets with the possible fog and when does the fog/stratus break up. There may be brief periods of 1/2 mile visibility around sunrise but there was not enough confidence in that to include it in the TAF. In addition, the timing of the fog/stratus dissipation may again be the early afternoon. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && SHORT TERM...Danielson LONG TERM...Entrekin AVIATION...Danielson
Hazardous Weather Outlook National Weather Service Denver/Boulder CO 1039 AM MST Wed Feb 10 2021 COZ030>051-111745- 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- 1039 AM MST Wed Feb 10 2021 This hazardous weather outlook is for northeast and north central Colorado. .DAY ONE...Today and Tonight Light snow showers and patchy fog will persist into the early afternoon across the urban corridor and plains. Temperatures will be cold today with highs in the low teens across much of the eastern plains. Light snow will continue across the mountains with an additional inch or two expected to accumulate throughout the day. More fog is possible late tonight over the eastern plains. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday Cold air will remain over the plains Thursday with even colder air moving in Friday and this weekend. By the weekend temperatures will be approaching records, with lows below zero and highs in the single digits above zero expected across most of the plains. Periods of light snow are likely, but little travel impact is expected. The most likely time for accumulating snow looks like Friday night and again Sunday. For the mountains, light snow is likely over the ridges through this weekend. There will be some increase in the snowfall late Friday into early Saturday along with a bit more wind. The valleys and foothills will have periods of light snow with a cooling trend through the weekend. Model forecasts are uncertain for the beginning of next week. There will likely be some moderation in temperatures, but there is also a chance of snow and windy conditions, especially in the mountains. .SPOTTER INFORMATION STATEMENT... Spotter reports will not be needed today or tonight.
The national radar mosaic for the moment the first event began.
5 winter weather. Local standard time, as filed.
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: 942774, 942775, 942776, 942777, 942778.