A large avalanche pushed a group of six snow boarders into the Sheep Creek gully of Loveland Pass. This is near but outside the Loveland Ski Area boundary.
Every event with a place to put it; 1 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.
A large avalanche pushed a group of six snow boarders into the Sheep Creek gully of Loveland Pass. This is near but outside the Loveland Ski Area boundary. Five of the six members of the group were completely buried. The survivor was was partially buried. The avalanche was approximately 650 feet wide, 1,150 feet long, and the fracture line was approximately eight feet deep. The avalanche is the deadliest in Colorado since 1962 when seven people were killed when a slide buried residents at Twin Lakes near Independence Pass.
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 Apr 20, 3:36 AM MST, 6 hours 39 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER/BOULDER CO 436 AM MDT SAT APR 20 2013 .SHORT TERM... A WEAK WEATHER DISTURBANCE EMBEDDED IN THE NORTHWEST FLOW ALOFT WILL MOVE ACROSS THE STATE TODAY WITH ITS MAIN IMPACT BEING FELT IN THE MOUNTAINS. PERIODS OF LIGHT SNOW ARE EXPECTED IN THE COLORADO HIGH COUNTRY THROUGH TODAY AND THIS EVENING DUE TO THE COMBINATION OF OROGRAPHIC FLOW...WEAK DYNAMIC LIFT UNDER THE LEFT EXIT REGION OF THE UPPER JET AND DAYTIME HEATING. RADAR ECHOES HAVE BEEN SLOW TO DEVELOP ACROSS THE STATE THIS MORNING...BUT DECENT SHOWER ACTIVITY WITH SOME EMBEDDED THUNDERSTORMS WAS LOCATED OVER NORTHERN UTAH LAST EVENING. THE NORTHERN UTAH AIRMASS WILL BE ADVECTING INTO OUR NORTHERN MOUNTAINS BY THIS AFTERNOON WHICH WILL HELP IN THE GENERATION OF PRECIPITATION. SNOW ACCUMULATIONS ARE STILL EXPECTED TO BE LESS THAN HALF A FOOT THROUGH THIS AFTERNOON AND TONIGHT...SO NO HIGHLIGHTS ARE NEEDED. ON THE PLAINS...HAVE HELD ON TO THE MENTION OF ISOLATED SHOWER ACTIVITY...ESPECIALLY FOR THE AFTERNOON AND EARLY EVENING. TEMPERATURES TODAY SHOULD BE WELL INTO THE 50S THROUGH THE AFTERNOON...SO NO SNOW IS EXPECTED AT LOWER ELEVATIONS. THE SHORT WAVE TROUGH AXIS IS EXPECTED TO MOVE ACROSS THE NORTHEAST PLAINS DURING THE EVENING HOURS. GENERALLY HIGH-BASED SHOWER ACTIVITY IS ANTICIPATED JUST AHEAD OF THE UPPER TROUGH AS IT MOVES OUT OF THE MOUNTAINS. .LONG TERM...WNW FLOW ALOFT WILL BE OVER THE RGN ON SUN WITH INCREASING FLOW ALOFT SUN AFTN INTO SUN NIGHT. CROSS-SECTIONS SHOW RATHER LIMITED MOISTURE IN THE MTNS THRU THE AFTN HOWEVER WITH DECENT LAPSE RATES AND APPROACH OF UPPER LEVEL JET WILL SEE SOME INCREASE IN SHOWER ACTIVITY BY AFTN INTO THE EVENING HOURS. AT LOWER LEVELS APPEARS THERE WILL BE A SLIGHT CHC OF SHOWERS SUN AFTN NR THE WY-NE BORDER IN VICINITY OF THE UPPER LEVEL JET OTHERWISE IT LOOKS DRY. HIGHS ON SUN WILL CONTINUE TO MODERATE WITH READINGS IN THE LOWER 60S ACROSS NERN CO EXCEPT NEAR THE WY BORDER WHERE LINGERING SNOW COVER MAY HOLD TEMPS IN THE 50S. BY MONDAY AN UPPER LEVEL TROUGH WILL MOVE INTO THE AREA FM THE NW WITH INCEASING MID LVL QG ASCENT MON AFTN INTO MON NIGHT. IN ADDITION A CDFNT WILL MOVE INTO NERN CO BY MON MORNING WITH INCREASING UPSLOPE FLOW BY AFTN INTO THE EARLY EVENING HOURS. CROSS-SECTIONS SHOW INCREASING MOISTURE THRU THE DAY WITH SOME POTENTIAL FOR BANDED PCPN DUE TO PROXMITY OF THE UPPER LEVEL JET. THUS SHOULD SEE A GOOD CHC OF PCPN BY AFTN INTO THE EVENING HOURS IN MOST LOCATIONS. APPEARS TEMPS WILL BECOME COLD ENOUGH IN THE AFTN FOR PCPN TO GRADUALLY CHANGE TO SNOW ACROSS MOST OF NERN CO WHICH WILL CONTINUE INTO MON NIGHT. IF EVERYTHING COMES TOGETHER RIGHT THERE COULD BE SOME POTENTIAL FOR HEAVY SNOWFALL IN THE MTNS FOOTHILLS AND ACROSS PORTIONS OF NERN CO HOWEVER AMOUNTS SHOULD NOT BE AS HIGH AS WHAT OCCURRED WITH THE LAST SYSTEM. FOR TUE THE UPPER LEVEL TROUGH SHOULD GRADUALLY MOVE SE OF THE AREA WITH PCPN CHANCES DECREASING DURING THE MORNING HOURS. HIGHS ON TUE WILL BE WELL BLO NORMAL WITH READINGS IN THE UPPER 30S TO LOWER 40S ACROSS NERN CO. BY WED DRIER AIR IN WNW FLOW ALOFT WILL SPREAD ACROSS THE AREA SO WILL KEEP THE FCST DRY EXCEPT FOR A SLIGHT CHC OF -SHSN IN THE MTNS. HIGHS ON WED ACROSS NERN SHOULD RISE BACK INTO THE LOWER TO MID 50S BASED ON LATEST 850-700 MB TEMPS. BY THU DRY NWLY FLOW ALOFT WILL BE OVER THE AREA WITH A CONTINUATON OF MODERATING TEMPS AS READINGS GET INTO THE MID 50S TO NEAR 60 OVER NERN CO. FOR FRI MOISTURE WILL INCREASE IN THE MTNS AND WITH NWLY FLOW COULD SEE A CHC OF -SHSN. OVER NERN CO WILL KEEP A DRY FCST WITH HIGHS IN THE LOWER 60S. && .AVIATION...AVAIATION IMPACTS SHOULD BE PRETTY MINIMAL TODAY. CEILIGNS ARE EXPECTED TO REMAIN PRETTY HIGH DUE TO THE DOWNSLOPING NATURE OF THE FLOW PATTERN. THE LATE AFTERNOON AND EARLY EVENING WILL SEE SOME HIGH-BASED SHOWERS DEVELOP WHICH MAY PRODUCE LOCALLY GUSTY WINDS. THERE WILL ALSO BE A SMALL CHANCE OF AN ISOLATED THUNDERSTORM OR TWO...GIVEN THAT LIGHTNING WAS OBSERVED OVER NORTHERN UTAH LAST AFTERNOON AND EVENING. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && SHORT TERM...DANKERS LONG TERM....RPK AVIATION...DANKERS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE DENVER/BOULDER CO 1011 AM MDT SAT APR 20 2013 COZ030>051-211615- 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- 1011 AM MDT SAT APR 20 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST AND NORTH CENTRAL COLORADO. .DAY ONE...TODAY AND TONIGHT SNOW WILL BE LIKELY OVER THE MOUNTAINS FOR THE REST OF TODAY AND THIS EVENING. SNOW WILL DECREASE SOMEWHAT AFTER MIDNIGHT. ACCUMULATIONS WILL BE 1 TO 5 INCHES. A FEW THUNDERSTORMS MAY ACCOMPANY THE SNOW SHOWERS DURING THE AFTERNOON HOURS. ON THE PLAINS...THERE WILL BE A CHANCE OF RAIN SHOWERS AND A FEW THUNDERSTORMS DURING THE LATE AFTERNOON AND EVENING HOURS. LOCALLY GUSTY WINDS WILL BE THE PRIMARY THREAT FROM THE SHOWERS AS THE PRECIPITATION AMOUNTS WILL BE LIGHT. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY IT WILL BE MILD ON SUNDAY WITH A CHANCE OF SNOW SHOWERS IN THE MOUNTAINS WITH A SLIGHT CHANCE OF RAIN SHOWERS ACROSS THE PLAINS. A COLD FRONT WILL MOVE INTO NORTHEAST COLORADO ON MONDAY AS ANOTHER UPPER LEVEL WEATHER DISTURBANCE CROSSES THE STATE. MORE SNOW WILL OCCUR IN THE MOUNTAINS WITH RAIN CHANGING TO SNOW ACROSS THE PLAINS BY MONDAY AFTERNOON. THE CHANCE OF PRECIPITATION WILL LINGER INTO TUESDAY...THEN DRIER WEATHER AND WARMER TEMPERATURES ARE EXPECTED THROUGH FRIDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT.
The national radar mosaic for the moment the first event began.
1 avalanche. Local standard time, as filed.
A large avalanche killed five snowboarders over Loveland Pass.
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, S & Se Grand / W Central & Sw Boulder / Gilpin / Clear Creek / Summit / N & W Park Counties Above 9000 Feet | 2013-04-20 | 32 | Male | Outside/Open Areas | Direct |
| Avalanche, S & Se Grand / W Central & Sw Boulder / Gilpin / Clear Creek / Summit / N & W Park Counties Above 9000 Feet | 2013-04-20 | 32 | Male | Outside/Open Areas | Direct |
| Avalanche, S & Se Grand / W Central & Sw Boulder / Gilpin / Clear Creek / Summit / N & W Park Counties Above 9000 Feet | 2013-04-20 | 33 | Male | Outside/Open Areas | Direct |
| Avalanche, S & Se Grand / W Central & Sw Boulder / Gilpin / Clear Creek / Summit / N & W Park Counties Above 9000 Feet | 2013-04-20 | 33 | Male | Outside/Open Areas | Direct |
| Avalanche, S & Se Grand / W Central & Sw Boulder / Gilpin / Clear Creek / Summit / N & W Park Counties Above 9000 Feet | 2013-04-20 | 36 | Male | Outside/Open Areas | Direct |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2013Every state in 2013This day in weather historyWarnings in Colorado, April 2013
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: 447506.