An unstable snowpack resulted in an increased number of avalanches across the region.
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.
An unstable snowpack resulted in an increased number of avalanches across the region.
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 Feb 17, 4:00 PM MST, 20 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SALT LAKE CITY UT 400 PM MST SAT FEB 17 2007 .SYNOPSIS...A RIDGE WILL MOVE EAST OF UTAH TONIGHT ALLOWING A MILD SOUTHWEST FLOW TO INCREASE TONIGHT THROUGH SUNDAY. A POTENT COLD TROUGH WILL MOVE ACROSS REGION SUNDAY NIGHT THROUGH MONDAY. WEAK RIDGING WILL RETURN FOR MIDWEEK. && .DISCUSSION...RIDGE WILL MOVE EAST TONIGHT ALLOWING SURFACE PRESSURES TO FALL OVER THE NORTHERN INTERMOUNTAIN AREA. THIS WILL ALLOW SOUTHEAST DRAINAGE WINDS OVER THE WEST CENTRAL AND NORTHWESTERN VALLEYS TO BE ENHANCED AFTER MIDNIGHT KEEPING TEMPERATURES FROM GETTING AS COLD AS THIS MORNING. HIGH LEVEL MOISTURE AS SEEN ON THE SATELLITE OVER BAJA CALIFORNIA AND OFF THE SOUTHERN CALIFORNIA COAST WILL BE LIFTED NORTHEAST ACROSS THE INTERMOUNTAIN REGION SUNDAY WITH LOWERING AND THICKENING CLOUDINESS DEVELOPING BY EVENING. SOME LIGHT SNOW OR FLURRIES POSSIBLE OVER THE MOUNTAINS BY NIGHTFALL. THE DENSE CLOUD SHIELD WILL KEEP TEMPERATURES FROM MAKING A RUN INTO THE LOWERS 60S OVER THE WESTERN VALLEYS BUT WITH BREEZY CONDITIONS TEMPERATURES WILL REACH WELL INTO THE UPPER 50S WESTERN VALLEYS AND 60S IN DIXIE. TEMPERATURES IN EASTERN AREAS WILL BE SOMEWHAT LESS MILD DUE TO LESS MIXING. THE TIMING OF THE COLD FRONT APPEARS TO BE ABOUT 2 TO 4 AM MONDAY MORNING AT SLC WITH ANY RAIN QUICKLY CHANGING OVER TO SNOW. WATER EQUIVALENTS BY THE GFS IS ABOUT 0.30 TO 0.60 OF AN INCH ALONG THE WASATCH FRONT SO SNOW AMOUNTS SHOULD EASILY BE WITHIN SNOW ADVISORY CRITERIA FOR THE PERIOD BETWEEN EARLY MONDAY MORNING THROUGH MONDAY AFTERNOON. THIS WOULD BE A COMMUTERS SPECIAL EXCEPT THAT MONDAY IS A HOLIDAY SO LESS TRAVELERS SHOULD BE ON THE ROADS. SNOW AMOUNTS IN THE NORTHERN MOUNTAINS WILL BE BETWEEN 8 AND 14 INCHES WHICH ALSO FITS INTO THE ADVISORY CRITERIA. WITH THE STORM SPLITTING BADLY OVER THE AREA THE SOUTH WILL NOT FARE AS WELL WITH THE MAJOR SOUTHERN BRANCH ENERGY GOING WELL SOUTH ACROSS SOUTHERN ARIZONA. THEREFORE WHILE SNOW ADVISORIES LOOK CERTAIN FOR THE NORTH THE SOUTH MAY ONLY BE MARGINAL FOR LOW END ADVISORY FOR BOTH MOUNTAINS AND WESTERN VALLEYS. GFS NOT AS COLD AS NAM AND PROBABLY THE WAY TO LEAN BUT WILL TAKE A MIDDLE OF THE ROAD APPROACH FOR NOW. ALSO THE NAM TREND OF BACKING AWAY FROM HAVING A 700MB LOW FORM OVER THE SOUTHWEST LOOKS CORRECT AS THE SUPPORT ALOFT MOVING WAY SOUTH. HIGH PRESSURE MOVES IN BY MONDAY NIGHT AND SHOULD PREVAIL THROUGH TUESDAY BEFORE SOME WARM ADVECTION MOISTURE MOVES ACROSS THE NORTH. GOOD LOOKING SYSTEM MOVING IN FOR FRIDAY AS GFS AND EC PRETTY MUCH IN AGREEMENT WITH THIS FEATURE ALTHOUGH THE EC HAS ANOTHER SYSTEM RIGHT ON ITS HEALS OFF THE WEST COAST THAT THE GFS HAS NO IDEA ABOUT. HOW THAT UPSTREAM ENERGY AFFECTS THIS FRIDAY SYSTEM WILL BE INTERESTING TO SEE. BUT THATS ANOTHER DAY. && .AVIATION...NO CONCERNS TODAY. HOWEVER SOUTH WINDS WILL LIKELY GUST OVER 25 MPH SUNDAY AT SLC DUE TO AN APPROACHING TROUGH. COLD FRONT AFTER MIDNIGHT SUNDAY NIGHT WITH POST FRONTAL SNOW. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...NONE. WY...NONE. && STRUTHWOLF FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT... HTTP://WEATHER.GOV/SALTLAKECITY (ALL LOWER CASE)
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SALT LAKE CITY UT 612 AM MST SAT FEB 17 2007 UTZ001>021-WYZ021-181300- CACHE VALLEY/UTAH PORTION-CASTLE COUNTRY- CENTRAL AND SOUTHWEST MOUNTAINS- GLEN CANYON RECREATION AREA/LAKE POWELL- GREAT SALT LAKE DESERT AND MOUNTAINS-HENRY MOUNTAINS- NORTHERN WASATCH FRONT-SALT LAKE AND TOOELE VALLEYS-SAN RAFAEL SWELL- SANPETE/SEVIER VALLEYS-SOUTH CENTRAL UTAH-SOUTHERN WASATCH FRONT- SOUTHWEST UTAH-SOUTHWEST WYOMING-UTAHS DIXIE AND ZION NATIONAL PARK- WASATCH MOUNTAIN VALLEYS-WASATCH MOUNTAINS I-80 NORTH- WASATCH MOUNTAINS SOUTH OF I-80-WASATCH PLATEAU/BOOK CLIFFS- WEST CENTRAL UTAH-WESTERN UINTA BASIN-WESTERN UINTA MOUNTAINS- 612 AM MST SAT FEB 17 2007 THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHWEST AND NORTH CENTRAL UTAH...THE CENTRAL AND SOUTHWEST UTAH MOUNTAINS AND SOUTHWEST WYOMING. .DAY ONE...TODAY AND TONIGHT HIGH PRESSURE ALOFT WILL BRING MOSTLY SUNNY SKIES AND UNSEASONABLY WARM TEMPERATURES TO THE STATE TODAY. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY A POTENT STORM SYSTEM IS EXPECTED TO IMPACT THE AREA SUNDAY AND MONDAY. WINDS ARE EXPECTED TO BECOME STRONG SUNDAY AFTERNOON... ESPECIALLY ACROSS HIGHER ELEVATIONS AND SOUTHWEST WYOMING. WIDESPREAD PRECIPITATION IS EXPECTED LATE SUNDAY NIGHT AND MONDAY... WITH RAIN AND SNOW IN THE VALLEYS AND SNOW IN THE MOUNTAINS. HAZARDOUS TRAVEL CONDITIONS ARE POSSIBLE SUNDAY NIGHT AND MONDAY MORNING ACROSS MUCH OF NORTHERN UTAH...SPREADING INTO SOUTHERN UTAH MONDAY AFTERNOON. STAY TUNED TO THE LATEST UPDATES ON THIS STORM. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. SMITH
3 avalanche. Local standard time, as filed.
Human-triggered avalanche on Tower Mountain claimed the life of a snowmobiler.
Human triggered avalanche on Signal Peak claimed the life of a snowmobiler.
Human triggered avalanche in Hells Canyon near Snowbasin claimed the life of a 17 year old male skier. The avalanche initiated around 8,500 on a north-northeast facing slope about 35-45 degrees in steepness. The avalanche descended about 1,500 vertical feet. The debris pile was 10-12 feet deep, and about 600 long by 60 feet wide.
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 Plateau/Book Cliffs | 2007-02-17 | 16 | Male | Outside/Open Areas | Direct |
| Avalanche, Central and Southwest Mountains | 2007-02-17 | 44 | Male | Outside/Open Areas | Direct |
| Avalanche, Wasatch Mountains I80 North | 2007-02-18 | 17 | Male | Outside/Open Areas | Direct |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Utah in 2007Every state in 2007This day in weather historyWarnings in Utah, February 2007
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: 13808, 13809, 13810.