Several days of heavy wet snow combined with strong winds to produce extreme avalanche conditions in the Wasatch Mountains. 4 people lost their lives in avalanches during this two day period.
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.
Several days of heavy wet snow combined with strong winds to produce extreme avalanche conditions in the Wasatch Mountains. 4 people lost their lives in avalanches during this two day period. One skier was killed when an avalanche he triggered in the Wasatch backcountry buried him in 2 to 3 feet of snow. A snowmobiler lost his life when he became stuck and was trying to dig his way out when a slab of snow above him cut loose and came down on top of him. The following day, two snowshoers perished when a large avalanche suddenly overtook them. One of the victims was buried in 9 feet of snow.
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 10, 9:50 AM MST, 3 hours 10 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SALT LAKE CITY UT 950 AM MST FRI DEC 10 2004 .SYNOPSIS...A STRONG RIDGE OF HIGH PRESSURE WILL BUILD INTO THE AREA TODAY AND WILL REMAIN INTO SUNDAY. A WEAK SYSTEM WILL MOVE THROUGH THE RIDGE ON MONDAY. && .DISCUSSION...LAST REMNANTS OF STRATOCUMULUS FROM THE MOIST NORTHWEST FLOW HANGING OVER THE NORTHERN ZONES WILL BE DISSIPATING THRU MIDDAY AS THE FLOW GRADUALLY BACKS AROUND AND WARMS. WARM START AND AFTERNOON SUN WILL MAKE FOR A VERY MILD DAY TODAY. PATCHY CIRRUS WILL CONTINUE TO STREAM THRU THE RIDGE OVERNIGHT AND COULD HOLD MINS UP SOMEWHAT ALLOWING TEMPS TO WARM BACK UP NICELY AGAIN TOMORROW IN SPITE OF THE STRONG SURFACE HIGH IN PLACE. EXPECT ENOUGH MIXING TODAY TO REMOVE FOG THREAT TONIGHT FROM ALL BUT THE CLOSED BASINS SUCH AS THE CACHE VALLEY AND THE MOUNTAIN VALLEYS. MORNING RUNS A BIT WEAKER ON THE SYSTEM FORECAST TO MOVE THRU THE RIDGE SUNDAY NIGHT AND MON...AND THIS IS TO BE EXPECTED FOR A SYSTEM CRASHING THRU SUCH A STRONG RIDGE. STILL...CLOUDS WITH THIS FEATURE AND A WEAK COLD FRONT WILL HELP PREVENT INVERSIONS FROM BECOMING TOO WELL ESTABLISHED. NEXT THREAT OF ANY WEATHER WILL BE MID WEEK AS ANOTHER LOW COMING THRU THE RIDGE SPLITS SOUTH THRU THE NRN ROCKIES THEN WESTWARD THRU THE GREAT BASIN. MODELS WILL HAVE A HARD TIME WITH ITS TRACK FOR A WHILE YET...AND BECAUSE IT IS A RELATIVELY SMALL FEATURE...IT WILL HAVE TO BE A DIRECT HIT ON OUR FORECAST AREA TO BRING ANY SIGNIFICANT PRECIP. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...NONE. WY...NONE. ID...NONE. && WILENSKY
4 avalanche. Local standard time, as filed.
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, W Summit T Nw/Se Salt Lake/Wasatch X Sc/E Utah/P X E Juab/X Nw San Pete | 2004-12-10 | 22 | Male | Outside/Open Areas | Direct |
| Avalanche, W Summit T Nw/Se Salt Lake/Wasatch X Sc/E Utah/P X E Juab/X Nw San Pete | 2004-12-11 | 42 | Male | Outside/Open Areas | Direct |
| Avalanche, W Summit T Nw/Se Salt Lake/Wasatch X Sc/E Utah/P X E Juab/X Nw San Pete | 2004-12-11 | 32 | Male | Outside/Open Areas | Direct |
| Avalanche, W Summit T Nw/Se Salt Lake/Wasatch X Sc/E Utah/P X E Juab/X Nw San Pete | 2004-12-11 | 59 | Male | Outside/Open Areas | Direct |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Utah in 2004Every state in 2004This day in weather historyWarnings in Utah, December 2004
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: 5431617, 5431618, 5431619, 5431620.