A prolonged period of strong winds, and heavy snow occurred across the mountains and higher foothills of northern Colorado. Peak wind gusts to 93 mph were recorded at the NCAR Mesa Lab in the foothills 2 miles south-southwest of Boulder, just ahead of the approaching winter storm.
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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.
A prolonged period of strong winds, and heavy snow occurred across the mountains and higher foothills of northern Colorado. Peak wind gusts to 93 mph were recorded at the NCAR Mesa Lab in the foothills 2 miles south-southwest of Boulder, just ahead of the approaching winter storm. In the Park and Gore Mountain ranges, SNOTEL sites over a 48-hr period, recorded storm totals from 35 to 49 inches! Elsewhere, storm totals from 1 to 2 feet were more common. In addition, extensive blowing snow from strong winds produced dangerous driving conditions over the higher mountain passes. Some of the roads and highways were closed for a time due to the inclement weather. In and near the Front Range Foothills, peak wind gusts included: 93 mph at the NCAR Mesa Lab, 89 mph near Winter Park, 85 mph at the junction of highways 93 and 72, and 76 mph, 2 miles south of Boulder.
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 Dec 1, 2:23 PM MST, 37 minutes earlier. Its key messages:
Area Forecast Discussion National Weather Service Denver/Boulder CO 223 PM MST Fri Dec 1 2023 .KEY MESSAGES... - Periods of snow and blowing snow will continue this evening through Saturday. - Snow and winds increase Saturday night with areas of moderate to heavy snow and significant blowing snow creating very difficult travel Saturday night and Sunday morning. - Strong winds are expected to develop across the mountains and higher foothills Saturday afternoon into Sunday, with a few gusts greater than 75 mph possible. && .SHORT TERM...(This evening through Saturday) Issued at 223 PM MST Fri Dec 1 2023 A cool but quiet start to the weekend is expected across the plains and Denver metro...with a different story for the high country. Most of the plains will be cool but dry on Saturday as the flow aloft increases. Temperatures should warm up a bit compared to today with highs in the low to mid 40s. We should also see gusty winds develop through the day as we mix into the strengthening mid-level flow. Across the high country, only a few light snow showers remain this afternoon, in a lull between shortwaves. There should be an increase in snow coverage through this evening as moisture increases ahead of our next shortwave trough traversing the area, though the heaviest snow will hold off until after midnight. Orographic snow showers will continue through the day Saturday with additional light snowfall accumulations likely. Have opted for a Winter Weather Advisory tonight through Saturday evening due to the combination of snow and blowing snow across some of the busier travel corridors in the mountains, with a Winter Storm Warning over the Park Range where heavier snow is expected. Winds will also increase across the higher elevations Saturday afternoon and evening behind the passage of the shortwave. Winds will generally remain in the high country during the early afternoon, as gusts will largely be mechanically mixed. As subsidence increases in the wake of the shortwave, we should see some fairly impressive mountain wave amplification late Saturday into Sunday. Guidance differs on the timing of this, but model cross-sections and Sangster data largely support the potential for wind gusts >75 mph. A High Wind Watch goes into effect Saturday afternoon... which will continue into Sunday. Both the snow and wind will continue through the weekend... continue reading the Long Term discussion below for additional details. .LONG TERM...(Saturday night through Friday) Issued at 223 PM MST Fri Dec 1 2023 A second and stronger short wave trough embedded in the the northwest flow aloft will dive southeast across the Northern and Central Rockies Saturday night and Sunday. The 12Z model runs are stronger with this system than previous runs, and thus have higher snowfall amounts. Ridge top winds reach 45 to 60 knots Saturday night and then slowly decrease Sunday afternoon through Sunday night. This will lead to good orographic lift in addition to the lift from the short wave. Expect a period of moderate to heavy snow late Saturday night and Sunday morning to accompany the wave as it passes overhead. It will also become very windy, leading significant blowing and drifting snow over the mountain passes. Travel in the mountains late Saturday night through Sunday morning is expected to become very difficult. Best to avoid traveling in the mountains during this time. We decided to issue a Winter Storm Warning for all of our mountains due to the blowing snow and increased snowfall amounts. For the mountain valleys, a winter weather advisory was issued where travel conditions will still be hazardous, but not as bas as over the mountains. Snowfall amounts for this storm look to be 1 to 2 feet for the mountains near Rabbit Ears Pass, with 6 to 14 inches for the rest of the mountains of north central Colorado. The mountains valley are expected to see 4 to 10 inches with the higher amounts expected to be found from Frasier to Grand Lake. East of the mountains, high winds to 80 mph will be possible in the foothills. A High Wind Warning was issued beginning Saturday mid afternoon. Appears a mountain wave sets up Saturday afternoon and evening. The threat for high winds will continue through Sunday morning. Even though the mountain wave breaks down Saturday night, Strong subsidence once the short wave passes will help transport stronger winds aloft to the foothills. Even with strong downslope winds, there will be a chance a little snow survives onto the foothills and near by plains. Any accumulation is expected to be light and less than an inch. For next week, ridging spreads across the intermountain west Monday. This will cause northwest flow aloft over Colorado to slowly decrease through the day. Light snow should linger in the northern mountains and end late in the day. Elsewhere, dry and mild conditions will prevail. Highs look to be in the upper 50s to around 60. Warming trend continues into Tuesday and Wednesday with ridging now over Colorado. Highs will push well into the 60s by Wednesday. The ridge flattens Thursday with west to southwest flow aloft over the Central Rockies. This will keep mild temperatures in place, though a weak cold front could knock temperatures down a notch Thursday and Friday. No rain or snow is expected for the upcoming week through Friday once the mountain snow ends on Monday. && .AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon) Issued at 1014 AM MST Fri Dec 1 2023 Main concerns will be briefly lowered ceilings this afternoon and stronger winds late Saturday morning into Saturday afternoon. Winds remain light this morning and will be light and variable for the next few hours, but should eventually take on a weak easterly component. The arrival of some better moisture may briefly lower ceilings (still somewhere between 6000-8000ft AGL), with a stray snow shower or two also possible. VFR conditions are expected tonight and Saturday. Guidance is in good agreement in mixing stronger west-northwesterly flow to the terminals near 18z Saturday, continuing into the afternoon/evening. && .BOU WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 8 PM Saturday to 11 PM MST Sunday for COZ030-032. Winter Storm Warning from 6 PM this evening to 11 PM MST Sunday for COZ031. Winter Weather Advisory from 6 PM this evening to 8 PM MST Saturday for COZ033-034. Winter Storm Warning from 8 PM Saturday to 11 PM MST Sunday for COZ033-034. High Wind Watch from Saturday afternoon through Sunday morning for COZ035-036. && SHORT TERM...Hiris LONG TERM...Meier AVIATION...Hiris
Hazardous Weather Outlook National Weather Service Denver/Boulder CO 1024 AM MST Fri Dec 1 2023 COZ030>051-021730- 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- 1024 AM MST Fri Dec 1 2023 This hazardous weather outlook is for northeast and north central Colorado. .DAY ONE...Today and Tonight Snow showers will continue across the mountains today and increase a bit tonight, with light snow accumulations expected. There is a slight chance of a snow shower or two across portions of the plains and Palmer Divide this evening, but no accumulation is expected. .DAYS TWO THROUGH SEVEN...Saturday through Thursday The mountains will continue to see periods of snow through the weekend, heaviest late Saturday night and Sunday. In addition to the snow, it becomes windy as well. Snow and blowing snow is expected to make travel difficult in the mountains Sunday. For the east slopes of the Front Range and plains, windy conditions develop Saturday and continue through Monday. The strongest winds are expected Sunday along the east slopes of the Front Range mountains and in the foothills. .SPOTTER INFORMATION STATEMENT... Snowfall reports from spotters will be appreciated.
The national radar mosaic for the moment the first event began.
3 winter storm, 2 high wind. Local standard time, as filed.
Storm totals included 40.5 inches just northeast of Rabbit Ears Pass, and 18 inches, 11 miles south of Rabbit Ears Pass.
Storm totals included: 28.5 inches, 9 miles south-southeast of Spicer; 16.5 inches near Longs Peak, and 12 inches, 6 miles east of Cameron Pass.
Storm totals included: 19.5 inches near Berthoud Pass, 16.5 inches near Loveland Pass, 13.5 inches near Copper Mountain, 5 miles west of Green Mountain Reservoir, and Lake Eldora.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2023Every state in 2023This day in weather historyWarnings in Colorado, December 2023
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: 1147327, 1147332, 1147333, 1147322, 1147323.