A skier injured his leg in an avalanche in Grand Teton National Park around 1430MST. The soft slab avalanche occurred in a portion of the park known as the Northwest Passage just outside the boundary of Jackson Hole Mountain Resort.
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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 RIW wrote it up.
A skier injured his leg in an avalanche in Grand Teton National Park around 1430MST. The soft slab avalanche occurred in a portion of the park known as the Northwest Passage just outside the boundary of Jackson Hole Mountain Resort. The skier was carried down a 50 foot slope by the 60-foot-wide, 2.5-foot-deep slide where he crashed against a tree. Park rangers and county search and rescue evacuated the injured man by helicopter.
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 Riverton, WY wrote its last area forecast discussion before the first event at Feb 24, 2:35 AM MST, 11 hours 55 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 235 AM MST THU FEB 24 2011 .SHORT TERM...TODAY THROUGH SATURDAY NIGHT COMPLEX PATTERN SHAPING UP FOR THE NEXT FEW DAYS OVER THE REGION WITH A POSITIVELY TROUGH OVER CENTRAL/WESTERN CANADA AND MUCH OF THE WESTERN CONUS. JET OVER MONTANA AND DAKOTAS WITH RIGHT ENTRANCE REGION DYNAMICS COUPLING WITH LEFT EXIT REGION DYNAMICS FROM A STRONGER JET MOVING ACROSS THE CENTRAL GREAT BASIN. AT THE SURFACE...AN ARCTIC FRONT HAS PUSHED THROUGH THE NORTH AND INTO CENTRAL EAST OF THE DIVIDE. BANDS OF SNOW FORMED THIS PAST EVENING ACROSS WESTERN AND NORTHERN WYOMING...BRINGING LIGHT AMOUNTS SO FAR. THE NORTHERN JET WILL MOVE ACROSS SOUTHERN WYOMING TODAY AND TONIGHT WITH THE DYNAMICS AIDING SNOWFALL OVER THE WEST TODAY AND TONIGHT BEFORE TAPERING. SOME STEEP LAPSE RATES ALONG WITH LI'S NEARING ZERO WILL ADD A CONVECTIVE ELEMENT...PROVIDING SOME LOCALIZED HIGHER SNOWFALL RATES. EXPECT 3 TO 6 INCHES OF SNOWFALL IN THE MOUNTAINS AND 1 TO 3 INCHES OVER THE LOWER ELEVATIONS BY LATE FRIDAY MORNING. SOME LOCALIZED ADVISORY AMOUNTS ARE POSSIBLE OVER THE TETONS/SALTS/WYOMINGS AND OVER THE STAR VALLEY AND THE COKEVILLE AREA. EAST OF THE DIVIDE...OVER-RUNNING PRECIPITATION WILL INCREASE OVER MOST OF THE AREA...WITH THE BETTER SNOWFALL OVER JOHNSON AND NATRONA COUNTIES AS WELL AS THE WESTERN BIGHORN BASIN. COULD SEE 1 TO 3 INCHES THERE WITH LOCALLY HIGHER AMOUNTS. SNOW WILL ALSO DEVELOP OVER SWEETWATER COUNTY THIS EVENING UNDER THE JET. SOME ADVISORY AMOUNTS WILL BE LIKELY OVER THE SOUTHEAST CORNER OF THE COUNTY...ALONG THE SURFACE WARM FRONT. ANOTHER JET MOVES IN FRIDAY AFTERNOON BRINGING ANOTHER ROUND OF SNOW TO MAINLY THE SOUTHERN HALF OF THE CWA...BUT AGAIN THE BEST CHANCE WILL BE ALONG THE BORDER ALONG THAT WARM FRONT. UNSETTLED CYCLONIC FLOW LINGERS SATURDAY WITH SOME LIGHT SNOW HANGING ON OVER THE WEST AND SOUTH...DRYING OUT OVER THE NORTH AND CENTRAL. AS FOR TEMPERATURES...IT WILL BE IN THE UPPER SINGLE DIGITS AND TEENS EAST OF THE DIVIDE BEHIND THE ARCTIC FRONT. THE SOUTH AND WEST WILL BE AHEAD OF THE FRONT AND WILL BE MAINLY IN UPPER TEENS AND 20S TODAY AND FRIDAY. THE ARCTIC FRONT WASHES OUT SATURDAY AS SOUTHWEST FLOW INCREASES...WITH TEMPERATURES REBOUNDING INTO THE 20S. .LONG TERM...SUNDAY THROUGH THURSDAY AN UPPER LOW MOVING EAST ACROSS THE FOUR CORNERS REGION INTO THE CENTRAL/SOUTHERN PLAINS...COULD RESULT IN SOME LINGERING SNOWFALL ACROSS THE EXTREME SOUTHERN AREA OF THE FORECAST AREA. OTHERWISE...A MAINLY DRY WESTERLY FLOW DEVELOPS ACROSS THE ROCKIES THROUGH WEDNESDAY. A COUPLE WEAK DISTURBANCES EMBEDDED IN THE WESTERLY FLOW COULD RESULT IN SOME SNOW WEST OF THE DIVIDE...SO WILL KEEP SOME SLIGHT POPS OVER THE WEST. MEDIUM RANGE MODELS THEN SHOW A MORE POTENT SYSTEM POSSIBLY AFFECTING THE AREA THURSDAY. HOWEVER...MODELS HAVE BEEN PUSHING BACK THIS NEXT SYSTEM ON A DAILY BASIS...SO WILL KEEP POPS LOW UNTIL MORE CONFIDENCE GROWS IN THE NEXT SYSTEM. THE ARCTIC AIR MASS ACROSS THE AREA IN SHORT TERM IS EXPECTED TO MODIFY QUICKLY BY SUNDAY AND MONDAY...WITH THE ARCTIC COLD FRONT REMAINING WELL NORTH AND EAST OF THE AREA DURING THE EXTENDED. STILL THINK MODELS ARE WARMING THINGS UP TOO QUICKLY IN THE TRAPPED BASINS PARTICULARLY ON SUNDAY. STRONG WESTERLY FLOW SHOULD RESULT IN STRONG WINDS AT TIMES IN TYPICAL WINDY AREAS SUNDAY NIGHT THROUGH THURSDAY. COULD SEE A HIGH WIND EVENT...BUT HARD TO PINPOINT ANY ONE GIVEN PERIOD AT THIS TIME. && .AVIATION... A SHALLOW ARCTIC FRONT WILL BACK TO THE EAST SLOPES OF THE DIVIDE THIS MORNING WITH WIDESPREAD MVFR CIGS/AREAS OF IFR CIGS BEHIND THE FRONT INCLUDING KCPR/KRIW/KLND/KWRL/KCOD. -SN WILL INCREASE AFTER 20Z BEHIND THIS FRONT WITH WIDESPREAD MVFR VSBYS/AREAS OF IFR VSBYS IN -SN THROUGH 04Z FRIDAY WITH DRYING/IMPROVING CONDITIONS FROM THE NORTH AFTERWARDS. WEST OF THE DIVIDE...A COUPLE OF UPPER LEVEL DISTURBANCES WILL PUSH ACROSS THE AREA. THE FIRST DISTURBANCE WILL BRING WIDESPREAD MVFR/AREAS OF IFR CONDITIONS IN -SN THIS MORNING THROUGH AROUND 16Z. A BRIEF BREAK AND SOME IMPROVEMENT IN CONDITIONS WILL FOLLOW THROUGH AROUND 20Z WITH THE SECOND DISTURBANCE BRINGING ANOTHER SHOT OF SIMILAR CONDITIONS THROUGH THE EVENING WITH DRYING/IMPROVING CONDITIONS FROM THE NORTHWEST AFTER 06Z FRIDAY. && .FIRE WEATHER... UNSETTLED CONDITIONS EXPECTED OVER THE NEXT FEW DAYS WITH SNOW EXPECTED OVER MOST OF THE WEST AND CENTRAL. IT WILL BE QUITE COLD EAST OF THE DIVIDE TODAY AND FRIDAY AS AN ARCTIC FRONT HAS MOVED THROUGH. IT WILL BE BREEZY TODAY WITH NORTH WINDS EAST OF THE DIVIDE AND SOUTHWEST TO NORTHWEST WINDS OVER THE SOUTH AND WEST. MOST OF THE SNOW WILL BE OVER BY SATURDAY...BUT WILL STILL LINGER OVER THE SOUTH AND WEST. TEMPERATURES WILL BEGIN TO MODERATE SATURDAY AS SOUTHWEST FLOW INCREASES. && .RIW WATCHES/WARNINGS/ADVISORIES... NONE. && SHORT TERM...TWB LONG TERM...WM AVIATION...AEM FIRE WEATHER...TWB
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 202 PM MST THU FEB 24 2011 WYZ001>020-022>030-251200- ABSAROKA MOUNTAINS-BIGHORN MOUNTAINS SOUTHEAST- BIGHORN MOUNTAINS WEST-CASPER MOUNTAIN-CODY FOOTHILLS- EAST SWEETWATER COUNTY-FLAMING GORGE- GREEN MOUNTAINS AND RATTLESNAKE RANGE-JACKSON HOLE-LANDER FOOTHILLS- NATRONA COUNTY LOWER ELEVATIONS-NORTH BIG HORN BASIN- NORTHEAST JOHNSON COUNTY-OWL CREEK AND BRIDGER MOUNTAINS- ROCK SPRINGS AND GREEN RIVER-SALT RIVER AND WYOMING RANGES- SOUTH LINCOLN COUNTY-SOUTHEAST BIG HORN BASIN- SOUTHEAST JOHNSON COUNTY-SOUTHWEST BIG HORN BASIN-STAR VALLEY- TETON AND GROS VENTRE MOUNTAINS-UPPER GREEN RIVER BASIN- UPPER GREEN RIVER BASIN FOOTHILLS-UPPER WIND RIVER BASIN- WIND RIVER BASIN-WIND RIVER MOUNTAINS EAST-WIND RIVER MOUNTAINS WEST- YELLOWSTONE NATIONAL PARK- 202 PM MST THU FEB 24 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TONIGHT LIGHT TO MODERATE SNOW WILL FALL OVER THE WEST TONIGHT...WITH 3 TO 6 INCHES IN THE MOUNTAINS AND 1 TO 3 INCHES IN THE VALLEYS BY LATE FRIDAY MORNING. AN ARCTIC FRONT WILL BRING COLD TEMPERATURES TO AREAS EAST OF THE DIVIDE TONIGHT INTO FRIDAY. SNOW WILL FALL TONIGHT...WITH 1 TO 2 INCHES POSSIBLE EXCEPT FOR THE BIG HORN BASIN WHERE LESS SNOW IS EXPECTED. SNOW WILL MOVE INTO SWEETWATER COUNTY THIS EVENING AND CONTINUE INTO FRIDAY. ONE TO THREE INCHES OF SNOW IS EXPECTED WITH LOCALLY HIGHER AMOUNTS OVER SOUTHEAST PORTIONS OF THE COUNTY. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY SNOW WILL CONTINUE FRIDAY AND FRIDAY NIGHT OVER THE SOUTHERN HALF OF WYOMING...WITH ADDITIONAL ACCUMULATIONS EXPECTED. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ASKED TO REPORT SNOWFALL. THANK YOU. TEAM RIVERTON
The national radar mosaic for the moment the first event began.
1 avalanche. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2011Every state in 2011This day in weather historyWarnings in Wyoming, February 2011
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: 276082.