A storm system produced a period of moderate to heavy snowfall over the northeast plains of Colorado, and impacted Logan, Phillips, Sedgwick and Washington counties. The heavy snow forced safety closures for portions of Interstate 76 and US-34 as the roadways became icy and snowpacked.
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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 storm system produced a period of moderate to heavy snowfall over the northeast plains of Colorado, and impacted Logan, Phillips, Sedgwick and Washington counties. The heavy snow forced safety closures for portions of Interstate 76 and US-34 as the roadways became icy and snowpacked. Colorado State Patrol reported that multiple drivers had slid off the road in Washington County. Storm totals ranged from 5 to 8 inches. One observer measured 9.7 inches of snowfall near Fleming. In and near the Front Range Mountains and Foothills, storm totals ranged from 3 to 8 inches. Roads were icy and slick at times, with poor visibility from patchy dense fog and snow. On the morning of the 8th, black ice that formed from melting snow overnight lead to several spinouts and accidents. The hazardous road conditions forced the closure of State Highway 93 in Jefferson County, which impacted the morning commute from Golden to 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 Mar 7, 4:38 AM MST, 22 minutes earlier. Its key messages:
Area Forecast Discussion National Weather Service Denver/Boulder CO 438 AM MST Thu Mar 7 2024 .KEY MESSAGES... - Moderate to very heavy snowfall rates are expected across the far northeast corner of Colorado today. Logan, Phillips, Sedgwick, and northeast Washington Counties will see 4 to 10 inches of snow. Dangerous travel conditions may develop as snowfall rates up to 2 to 3 inches per hour are possible. - Moderate to briefly heavy snow will fall this afternoon and evening across the Front Range mountains and foothills. Snow (mixed with rain) will develop across the I-25 corridor. Light snow amounts are expected with less snow to the east of I-25. - Warmer and drier this weekend. && .SHORT TERM...(Today and tonight) Issued at 400 AM MST Thu Mar 7 2024 Water vapor satellite shows a southwest to northeast oriented jet stream draped across southeast Colorado with our forecast area generally being in the left exit region which is providing lift. Nighttime microphysics satellite is showing an area of low clouds entering Colorado from Nebraska and also an area coming from southwest Kansas. These both indicate the healthy low level moisture moving into our forecast area. SPC mesoanalysis shows moderate 700 mb frontogenesis across far northeast Colorado. This frontogenesis is already helping to create showers and even a few thunderstorms this morning mainly over Washington and Logan Counties. This precipitation is ahead of schedule. There will be a combination of factors that will help to create very heavy precipitation across the far northeast plains today. The two aforementioned areas of low clouds and moisture will meet during the mid morning. 700 mb frontogenesis will increase throughout the morning and with this moisture, it will develop heavy showers and thunderstorms. Most models show this area of heavy precipitation will form a vorticity max or even a small MCV which could enhance precipitation rates further. There are two primary forecast challenges with this precipitation. The first is precipitation type. Current wet bulb temperatures are around 33 or 34 F and most areas are reporting rain. Once the morning progresses, the area of precipitation is expected to be heavy enough such that dynamic cooling lowers temperatures enough for the precipitation to switch over to snow. Assuming it does switch over to snow, snowfall rates up to 2 or 3 inches an hour are possible which would make travel dangerous. The other forecast challenge is where does the heaviest precipitation fall. Models are all over the place on the placement of the precipitation max. The NAM puts down almost 2 inches of QPF in Sydney, NE while the ECMWF highlights the heaviest precipitation to be in southeast Washington County. Most guidance seems to focus on Logan, Phillips, Sedgwick, and northeast Washington Counties to see the heaviest QPF and snowfall. Therefore, the forecast was changed drastically to indicate 4 to 10 inches of snow in those areas. A Winter Storm Warning was issued as this heavy, wet snow with potentially extreme snowfall rates could make for dangerous travel today. It would not be completely shocking that if this precipitation falls as almost all snow, we could see snowfall amounts approach 12 to 16 inches. There is a chance that this precipitation falls as mostly rain and the heaviest QPF misses our area. In that case, snowfall amounts could be quite a big lower than forecast with totals towards the 4 inch side of the range. The other highlight issued on the northeast plains was a Winter Weather Advisory for northeast Weld and Morgan Counties. While the bulk of the snow will miss these counties, it is possible the max precipitation amounts shift westward, as has happened with many systems in the past, and produce heavy snow in those counties. The main forcing and moisture will be in far northeast Colorado all day today and that will result in less forcing and moisture for the mountains, foothills, and I-25 corridor. Recent model runs have lowered QPF and snow amounts for these areas. It is still expected that convective snow showers will form over the Front Range mountains and foothills this afternoon due to instability and steep lapse rates. Some of these snow showers may become moderate to heavy at times with snowfall rates up to 1 inch an hour. With 5 to 11 inches of snow expected, the Winter Storm Watch was upgraded to a Winter Weather Advisory as hazardous travel may occur. Across the I-25 corridor, there is a lot of uncertainty with regards to snowfall. Soundings show an inversion around 750 mb that will be tough to overcome especially to the east of I-25. Snow amounts to the east of I-25 should be between a trace to 2 inches. To the west of I-25, the easterly, upslope flow will aid in producing higher snow amounts generally in the 1 to 4 inch range. This is a type of event where the west side of cities like Boulder and Golden do much better in terms of snowfall than any other cities. The low level easterly flow and cooler temperatures due to higher elevation will mean snow showers will be heavier and accumulate more as they hit the ground in those areas. There was strong consideration for issuing a Winter Weather Advisory for eastern Boulder and Jefferson Counties and one may be needed later today. However, the recent model guidance has come in so light on the snow amounts that no highlights were issued. Otherwise, today will be cool and cloudy. This will limit high temperatures as highs were lowered in the forecast to the low to mid 30s across the far northeast plains and the upper 30s across the I- 25 corridor. .LONG TERM...(Friday through Wednesday) Issued at 400 AM MST Thu Mar 7 2024 Linger snow showers continue through Friday afternoon across the northeastern corner. With the possibility of snow covered roads and the potential for an additional 1-2 inches through Friday morning, will allow the Winter Storm Warnings until noon Friday. Light snow begins to taper off across the foothills and mountains by Friday evening. An additional 2-3 inches for the higher elevations seems reasonable given the brief period of upslope Friday morning. With colder air in place and mostly cloudy skies expected, afternoon temperatures will struggle to increase. Most areas sit between the lower 20s to the lower 30s. Drier air enters the mid-levels quickly starting Saturday morning due to a ridge pattern replacing the trough. With the uptick in QPF during Thu/Fri system for the northeastern corner, decided to lower Saturday afternoon high temperatures due to snow cover. Highs should range from 44-50 for the plains and 20-35 for the mountain and valleys. Clear skies across the region should lead to snow melt for the urban corridor Saturday. Similar conditions will occur Sunday afternoon. Bufkit soundings indicate weak northwest flow aloft which will likely keep surface wind gusts light this weekend. Relative humidities decrease into the lower teens across the eastern plains but light winds should keep fire weather concerns low. By next week, a short wave arrives Tuesday but there is differences on timing across 500mb ensembles. For now, will continue with NBM forecast. && .AVIATION...(For the 12Z TAFS through 12Z Friday morning) Issued at 431 AM MST Thu Mar 7 2024 VFR conditions will persist until 14-15Z when a secondary push of northeast winds likely bring lower ceilings. The most likely ceiling height will be between 800-1,200 feet. However, ceilings could come in below 500 feet which would be impactful for arrival rates. Snow showers (possibly mixed with rain early on) may form late in the afternoon and evening. The heaviest snow is expected to develop in/near the foothills(KBJC), with lighter snow farther east toward KDEN. Snow showers or BR will reduce visibility throughout most of the night tonight. Visibility will likely be in the 3-6 SM range for much of the night and may get lower towards Friday morning. Improvements to ceilings and visibility may not come until midday Friday morning and VFR conditions will return late Friday. As for winds, light northeast winds will become gusty this afternoon. Gusts up to 25 knots could occur between 20-00Z this afternoon. && .BOU WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 11 AM this morning to 5 PM MST Friday for COZ033>036. Winter Weather Advisory from 8 AM this morning to 11 AM MST Friday for COZ042-044. Winter Storm Warning until 11 AM MST Friday for COZ048>051. && SHORT TERM...Danielson LONG TERM...AD AVIATION...Danielson
Hazardous Weather Outlook National Weather Service Denver/Boulder CO 244 AM MST Thu Mar 7 2024 COZ030>051-080945- 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- 244 AM MST Thu Mar 7 2024 This hazardous weather outlook is for northeast and north central Colorado. .DAY ONE...Today and Tonight Rain over the far northeast corner of Colorado will switch to a heavy, wet snow this morning and the snow will continue into the evening. Snow accumulation up to a foot is possible in and around Sterling, Holyoke, and Julesburg. Travel will be hazardous through Friday morning. In Fort Morgan and eastern Weld County, there is more uncertainty with regards to snow amounts but there is a small chance of heavy snow. Travel may be impacted in those locations as well. The Front Range mountains and foothills will see snow develop this afternoon and it will continue into Friday. Storm total snow accumulations of 5 to 11 inches are possible in these areas. The mountain valleys will have occasional light snow showers with total accumulations of 1 to 4 inches. Rain and snow showers will form over the I-25 corridor this afternoon becoming all snow this evening. Snow accumulations of 1 to 3 inches are expected with higher amounts up to 5 or 6 inches possible next to the foothills in cities like Boulder and Golden. The evening rush hour could be impacted from this snow. .DAYS TWO THROUGH SEVEN...Friday through Wednesday Snow covered roads are possible during Friday morning commute especially across I-76. Snow continues with an additional 2-3 inches for the foothills and mountains through Friday evening. For lower elevations such as the plains and Palmer Divide, an additional 1-2 inches could occur through Friday afternoon. Warmer and drier conditions are likely this weekend through early next week which may lead to snow melt. .SPOTTER INFORMATION STATEMENT... Spotter are encouraged to send snowfall reports.
The national radar mosaic for the moment the first event began.
4 winter storm, 4 winter weather. Local standard time, as filed.
A spotter measured 9.7 inches of snowfall, 3 miles south-southwest of Fleming.
A spotter measured 7.0 inches of snowfall, 5.7 miles west of Otis.
A spotter measured 8.0 inches of snowfall, 13.7 miles south of Ovid.
A storm total of 8.0 inches of snowfall in Haxtun and near Fairfield, with 5 inches near Holyoke.
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, March 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: 1155203, 1155204, 1155205, 1155206, 1155215, 1155216, 1155217, 1155218.