Snowboarders died in avalanches in Millcreek Canyon and Big Cottonwood Canyon.
Every event with a place to put it; 2 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 SLC wrote it up.
Snowboarders died in avalanches in Millcreek Canyon and Big Cottonwood Canyon.
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 Salt Lake City, UT wrote its last area forecast discussion before the first event at Dec 28, 3:55 AM MST, 8 hours 5 minutes earlier.
Area Forecast Discussion National Weather Service Salt Lake City UT 355 AM MST Sat Dec 28 2024 .SYNOPSIS...An active weather pattern will bring periods of precipitation to the region through New Years Day, with substantial mountain snow accumulations for the northern and central mountains. && .SHORT TERM (Through 12Z Monday)...The active pattern continues with another round of heavy mountain snow expected from the Wasatch Plateau northward. Early morning upper air and satellite analysis indicates a landfalling atmospheric river event continues across the PACNW into the Great Basin. IVT anomalies near the 90th percentile will transition to the maximum in the climatology period with the NAEFS by this evening across portions of northern Utah. Several shortwave troughs continue to ripple through this westerly flow and will bring periods of moderate to heavy mountain snow and valley rain through at least Sunday morning across mainly northern Utah. Expect precipitation to continue increase in coverage/intensity through 5 to 6 AM as better forcing builds into the area. With modest warm air advection ongoing, expect snow levels to gradually rise through the day...starting around 5000-5500 feet around 6 AM, reaching 7000-7500 feet by early evening. While most mountain areas will remain snow, this snow will be heavy and dense compared to the typical Utah powder. If your plans take you into the northern Utah mountain backcountry, please continue to monitor avalanche forecasts and warnings from the Utah Avalanche Center. Heavy mountain snow will continue through the evening in a modest warm air advection regime, gradually decreasing in intensity after midnight. With impressive IVT anomalies, strong forcing and orographic enhancement, guidance trended upwards with snow totals for the northern mountains. Note that there is a wider range of potential values than normal in snow totals and snow water equivalent. A portion of the ensemble envelope can struggle in these type of events, for example overconvecting (HRW, typically) or underdoing the orographic component. Some members of the HREF came in quite hot, with snow water equivalent in excess of 3 inches for portions of the Wasatch. For now, the most likely range of snow totals (25th to 75th percentile) is 8 to 16 inches additional accumulation, with locally higher amounts approaching 2 feet for the upper Cottonwoods. It should be noted that guidance also has a relatively wide range of snow ratios, anywhere from 3:1 (more like New England numbers) to 7:1 or 9:1 in the warmest part of the system tonight into Sunday morning. Thus, the current snow totals represent the most likely snow ratios, but represent a potential scenario where snow water amounts are on track, but snow totals are lower than forecast. By Sunday morning, precipitation will be ending...for a brief period. Another shortwave trough will cross northern Utah later Sunday into Monday. This system will have a stronger cold front cross the area Sunday night/early Monday, bringing crashing snow levels to near 4500 feet by Monday morning. Current forecast keeps snow totals for the northern mountains below advisory amounts, but will need to continue to monitor trends. Continued the winter storm warnings as is, but did adjust snow totals higher. .LONG TERM (After 12Z Monday)...A cold frontal boundary will be exiting the region around the start of the long term period. Locally, the forecast region will remain in cold unsettled deep northwesterly flow. In addition to resulting in much colder temperatures, what limited lingering moisture remains will yield some snow showers, particularly for the high terrain. Overall though will see chances diminish through the day, and any accumulations are likely to be quite light. On Tuesday a weak reinforcing shortwave impulse moves through within the maintained northwesterly flow. While a few ensemble members carry a bit more moisture with this feature (and higher precipitation chances accordingly), most guidance sources suggest very little in the way of available moisture. As a result, only see a modest uptick in snow shower chances for the high northern terrain. Outside of moisture, this shortwave also looks to provide an extra shot of reinforcing cold air. Temperatures Tuesday morning already will start quite low, with the forecast carrying teens to low 20s across the Cache Valley and Wasatch front, and even subfreezing temperatures to Lower Washington County. These dip even further for Wednesday morning, with more widespread teens across the Wasatch Front and even 20s for portions of Lower Washington County. These cold temperatures will be more realized in spots where skies clear sufficiently overnight to enhance radiational cooling. A couple more fairly weak embedded impulses brush by the region for the back half of the work week, though ridging will gradually be amplifying across the W CONUS. Once again these impulses only result in a very minor uptick in precipitation chances, most pronounced across high northern terrain, though expect if the ridge trends stronger these numbers will decrease. To that end, GEFS members for Alta overwhelmingly carry little to no water, while a little over half of ECM members carry some light amounts. Even then, far far below anything like that of the prior weekend's activity. Otherwise, with the increasing influence of the ridge, will see temperatures rebound upwards areawide and return to above climatological normal values. Some guidance shows a quick shortwave pushing through the region by Saturday, but given a good bit of differences between models and it being a week out in time, confidence and certainty in any details is quite low at this time. && .AVIATION...KSLC...Active pattern continues, resulting in numerous periods of precipitation through the TAF period. Thermal profile gradually warms through the period, so anticipate any frozen mix to favor rain by late Saturday morning. IFR conds more likely in mixed precip, with MVFR more favored during rain. Even during periods of VFR, CIGS likely to result in full or partial mountain obscuration. A brief quieter period with some amount of clearing expected Saturday night into Sunday morning. Winds anticipated to maintain southerly direction component, with some gusts during the daytime. .REST OF UTAH AND SOUTHWEST WYOMING...Southern terminals expected to see fairly quiet weather, with mostly diurnally normal winds and a mix of mid/high cloud cover. Northern terminals to see a more active cycle, with periods of precipitation anticipated at most. Thermal profile gradually warms, with many areas seeing initial snow levels ~5000 ft MSL rising to 6000-6500 ft MSL or higher by late Saturday morning. Resulting p-types then largely elevation dependent, with more rain mixing in at most by late Saturday morning. IFR or lower conds likely in periods dominated by snow, with MVFR more likely with rain. Even if VFR, many terminals near terrain will maintain some amount of mountain obscuration. Winds at northern terminals generally favor southerly direction component, with many seeing some gusts during the daytime. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...Winter Storm Warning until 11 PM MST this evening for UTZ110>113. WY...None. && Kruse/Warthen For more information from NOAA's National Weather Service visit... http://weather.gov/saltlakecity
The national radar mosaic for the moment the first event began.
2 avalanche. Local standard time, as filed.
A man was snowboarding in the Porter Fork area of Millcreek Canyon when he was caught by an avalanche. He was dug from the snow several days later.
A snowboarder died in an avalanche in Silver Fork of Big Cottonwood Canyon.
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, Wasatch Mountains South of I-80 | 2024-12-28 | 38 | Male | Outside/Open Areas | Direct |
| Avalanche, Wasatch Mountains South of I-80 | 2024-12-31 | 1 | Male | Outside/Open Areas | Direct |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Utah in 2024Every state in 2024This day in weather historyWarnings in Utah, 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: 1224975, 1224980.