Heaviest snowfall occurred in the Park and Gore Mountain ranges. 8 inches of precipitation.
Every event with a place to put it; 3 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.
Heaviest snowfall occurred in the Park and Gore Mountain ranges. Snotel stations here reported up to 1.8 inches of precipitation. Using a 10:1 ratio, an estimated up to 18 inches fell. Lighter snowfall occurred through out the rest of the northern mountains.
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 28, 4:30 AM MST, 6 hours 30 minutes earlier. Its key messages:
Area Forecast Discussion National Weather Service Denver/Boulder CO 430 AM MST Sat Dec 28 2024 .KEY MESSAGES... - Two more rounds of snow and travel impacts for the mountains through Monday. 1) This afternoon through Sunday morning. 2) Late Sunday evening to Monday. For both of these, the Park Range will see the heaviest snowfall totals while the Front Range mountains and Summit County will see moderate snowfall totals. - Windy Monday with at least elevated if not critical fire weather concerns. Relatively high probabilities (>50% chance) of reaching high wind criteria over portions of the foothills and plains. - A weak disturbance or two in northwest flow Tuesday into Wednesday could bring a couple light snow showers, favoring the mountains. - Colder temperatures are expected for New Year's Eve and start to 2025 (Wednesday). Then gradual warming again the end of next week. && .SHORT TERM /Through Tonight/... Issued at 245 AM MST Sat Dec 28 2024 This morning, GOES-18 shows a plume of Pacific moisture arriving to Utah Colorado border. No major changes to the short-term forecast today as an upper level jet will provide enough forcing and moisture to bring additional snowfall to the mountains starting this afternoon. Before the next system arrives, cloud cover will begin to increase across the region this morning. Cross sections display layer of dry air entering before round two of mountain snow, thus any additional snowfall this morning should be minimal. This will allow for a break in snowfall before this afternoon before our next Winter Storm Warning and Winter Weather Advisories go into effect. There is some uncertainty in warming this afternoon for the lower elevations due to cloud cover but downslope winds may warm temperatures this afternoon. Highs should reach the upper 40s to low 50s across the plains. Temperatures slightly above normal are expected for the mountains and valleys between 20-33. An upper level 120kt jet will assist in orographic snow starting early this afternoon. Similar to yesterday, areas above 10k feet such as Rabbit Ears Pass, Berthoud Pass and Cameron Pass will receive the highest accumulations resulting in 8-18 inches. Expecting mountain valleys and other mountain passes such as Loveland Pass will receive 2-6 inches through Sunday morning. Additionally, strong northwest flow will lead to strong winds producing wind gusts up to 55 mph over the mountain passes. Areas included in the Winter Storm Warning and Winter Weather Advisory will experience travel impacts such as low visibility due to blowing snow and snow covered roads especially by this evening. Gusty downslope winds will enter the lower elevations nearby the foothills as well. Wind gusts up to 35-45 mph could occur mainly along the adjacent plains through this evening. Tonight, difficult travel will be possible over the northern mountain passes as snowfall and strong wind gusts continue through late Sunday morning. && .LONG TERM /Sunday through Friday/... Issued at 245 AM MST Sat Dec 28 2024 Sunday will start the day with continued snow in the mountains due to strong orographic forcing, but that will wind down rather quickly by late morning into early afternoon (from south to north) as upper level ridging and warm advection occurs. The existing Winter Weather highlights til 11 am seem good for now, although impacts could linger a little longer in the northern border area with strong orographics but only shallow moisture lingering into early afternoon. The mountain wave is expected to retreat into the higher foothills and mountains of the Front Range and stay there most of Sunday with a lack of mountain top stable layer. Temperatures will be a little tricky tomorrow, but with warm advection we should see highs bump up into the 55 to 60 degree range, with the warmest readings around Denver where inversions are shallowest. We'll still have to watch how much upper level cloudiness occurs with some potential for a standing mountain wave cloud. That could trim temps a few degrees especially where inversions are a bit deeper to start the day. The next powerful Pacific jet is still due in by Sunday evening. We'll get into the left exit region of a 140-150 kt jet, aiding lift and bringing yet another round of snow, blowing snow, and hazardous travel to the mountains. While initially the airmass is relatively dry, the persistent lift and moisture on the poleward side of the upper level jet should get snow going again through the course of Sunday evening, becoming heavier in the overnight hours as lapse rates kick back up to 6-7C/km. Strong orographics will continue, so further highlights will be warranted (with the next main forecast package this afternoon) for the northern mountains. There is enough instability to bring the chance of rain and snow showers onto the adjacent plains late Sunday night. Mountain snow and blowing snow will continue into Monday morning, before gradually diminishing during the afternoon hours. That said, impacts will likely remain with hazardous travel conditions due to blowing snow, slick roads, and reduced visibility. Meanwhile, strong and gusty winds will develop Monday morning in the wake of the strong shortwave and speed max. Large scale subsidence and cold advection means a bora wind event is expected, with a relatively high (50-60% chance) of reaching high wind criteria across portions of the foothills and plains per ensemble and Sangster wind program forecasts. It still looks like the strongest winds will occur in the foothills due to subsidence and slight mountain wave enhancement, while another corridor of potentially high winds (>58 mph) develops from northern Larimer and Weld Counties east and southeast across the plains east of Denver. With the magnitude of winds and lack of precipitation/snow cover, critical fire weather conditions will be possible. More on that in the fire weather section below. Blowing dust will also be a distinct possibility where winds are strongest. Winds and weather will settle down Monday night into Tuesday. Continued cold advection means a couple days of below normal temperatures for a change, just in time for the last day of 2024 and a welcome into the New Year. Since we're in northwest flow for Tuesday and Wednesday, we can't rule out shortwaves passing by and providing a couple shots of snow showers. That said, ensemble systems were insisting on one thing with regard to intensity...light. At most a tenth of an inch of liquid (1.5" of snow) in the lower elevations and the vast majority of runs were still dry. We'll keep our fingers crossed - if you like snow. Otherwise, there is still reasonable agreement we'll be trending a little warmer for the end of next week. Models may still be overdoing the amount of warming though since we'll still be open to northwest flow and possible weak shortwaves and backdoor cold fronts. That all depends on progression of the upper Great Lakes trough, where ensembles show a fair amount of uncertainty. && .AVIATION /12Z TAFS through 12Z Sunday/... Issued at 430 AM MST Sat Dec 28 2024 VFR conditions will continue through the TAF period. The strong westerly downslope winds will be the main impact to terminals starting this afternoon. By 19-21Z, westerly winds should prevail for all sites. KBJC will likely receive the strongest gusts up to 32kts and a bit earlier, but KDEN should remain near 23-25kts this afternoon. Wind speed should decrease by this evening 00Z-02Z for KAPA and KDEN and may become variable for a few hours. Then winds should return to a south or south/southeast direction toward 03Z-06Z but speeds around 10 kts or less. Meanwhile, downslope winds are possible at KBJC through tonight, but mountain wave breaking is expected to mostly retreat to the foothills. There is a very low chance of a brief rain/snow shower arriving to KBJC tonight, but KDEN and KAPA will remain dry. && .FIRE WEATHER... Issued at 245 AM MST Sat Dec 28 2024 Critical fire weather conditions may develop Monday due to strong, gusty winds. Humidity levels will stay above traditional critical thresholds, but the magnitude of winds (gusts 45-60 mph likely across all of the foothills and plains) and recent dryness/lack of snow cover means high grassland fire danger. We'll continue to monitor the latest for possible highlights Monday. && .BOU WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning until 6 AM MST early this morning for COZ031. Winter Storm Warning from 11 AM this morning to 11 AM MST Sunday for COZ031. Winter Weather Advisory until 6 AM MST early this morning for COZ033-034. Winter Weather Advisory from 11 AM this morning to 11 AM MST Sunday for COZ033-034. && SHORT TERM...AD LONG TERM...Barjenbruch AVIATION...AD FIRE WEATHER...Barjenbruch
Hazardous Weather Outlook National Weather Service Denver/Boulder CO 309 AM MST Sat Dec 28 2024 COZ030>051-291015- 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- 309 AM MST Sat Dec 28 2024 ...TWO MORE ROUNDS OF SNOW AND BLOWING SNOW FOR THE MOUNTAINS... This hazardous weather outlook is for northeast and north central Colorado. .DAY ONE...Today and Tonight Another round of light to moderate snowfall will occur for the northern mountains until Sunday morning. Areas above 10 thousand feet such as Rabbit Ears Pass, and Cameron Pass will receive the highest accumulations resulting in 9-18 inches. Travel impacts can be expected in the mountains; prepare for low visibility due strong wind gusts of 45-55 mph and snow covered roads starting this afternoon. Overnight, snow may become heavy at times for these areas. Elsewhere, lower elevations will remain dry and gusty with wind gusts up to 40 mph. .DAYS TWO THROUGH SEVEN...Sunday through Friday Snow and blowing snow in the northern Colorado mountains will wind down late Sunday morning into early afternoon. Thus, the hazardous travel conditions will improve for the afternoon into the early evening hours Sunday. However, another round of heavier snow, blowing snow, and difficult travel conditions will develop in the mountains by late Sunday evening and continue through at least mid day Monday. Conditions are expected to gradually improve later Monday afternoon or Monday night. Strong and gusty winds will develop in all areas Monday. There is a possibility of high winds to around 60 mph, critical fire weather conditions, and even areas of blowing dust on the plains. Colder temperatures but lighter winds will settle in for Tuesday and Wednesday, before a gradual warmup occurs later next week. Light snow showers will still be possible from time to time, mainly in the mountains. .SPOTTER INFORMATION STATEMENT... Snowfall reports from mountain spotters will be appreciated.
The national radar mosaic for the moment the first event began.
2 winter weather, 1 winter storm. Local standard time, as filed.
Snotel stations here reported up to 1.8 inches of precipitation. Using a 10:1 ratio, an estimated up to 18 inches fell at the Zirkel Snotel. The Columbine Snotel received an estimated 14 inches of snow.
Snotel stations through the zone reported 0.4 to 0.9 precipitation. Using a 10:1 ratio, snowfall are estimated to be 4 to 9 inches, which led to snow covered roads.
Snotel stations through the zone reported 0.4 to 1.0 precipitation. Using a 10:1 ratio, snowfall are estimated to be 4 to 10 inches, which led to snow covered roads.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2024Every state in 2024This day in weather historyWarnings in Colorado, December 2024
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: 1224601, 1224605, 1224607.