A fast moving winter storm brought heavy snow to portions of western and central Wyoming. Up to 10 inches of snow fell across portions of the Star Valley with 6 to 8 inches across the southern Big Horn Basin from Thermopolis to Big Trails.
Every event with a place to put it; 3 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 RIW wrote it up.
A fast moving winter storm brought heavy snow to portions of western and central Wyoming. Up to 10 inches of snow fell across portions of the Star Valley with 6 to 8 inches across the southern Big Horn Basin from Thermopolis to Big Trails.
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 Nov 8, 10:25 PM MST, 35 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 1025 PM MST THU NOV 8 2012 .SHORT TERM...TONIGHT THROUGH SUNDAY SNOW AND WIND WILL SPREAD ACROSS THE WEST TONIGHT...WITH INCREASING SOUTHWEST WINDS ALONG AND EAST OF THE CONTINENTAL DIVIDE. SNOWFALL OF 6 TO 12 INCHES IN THE MOUNTAINS WITH 3 TO 6 INCHES IN THE VALLEYS CAN BE EXPECTED BY FRIDAY EVENING. THE SNOW WILL BE ACCOMPANIED BY STRONG SOUTHWEST WINDS WITH GUSTS OVER 50 MPH OVER THE HIGHER PEAKS. A WINTER WEATHER ADVISORY IS IN EFFECT. AHEAD OF A STRONG COLD FRONT...HIGH WINDS ARE POSSIBLE FRIDAY AFTERNOON AND EVENING ACROSS EASTERN SWEETWATER... SOUTHERN FREMONT AND NATRONA COUNTIES. WIND GUSTS AROUND 60 MPH ARE POSSIBLE. THE CHANCE OF SNOW WILL SHIFT TO THE NORTH AND EAST FRIDAY EVENING THROUGH SATURDAY AS A STRONG COLD FRONT WILL PUSHES SOUTH FROM MONTANA WITH MUCH COLDER TEMPERATURES FOR THE WEEKEND. THE SNOW WILL DECREASE SATURDAY NIGHT WITH COLD...AND MAINLY DRY CONDITIONS EXPECTED SUNDAY. THE NORTHERN AND WESTERN MOUNTAINS COULD SEE LINGERING SNOW SHOWERS SUNDAY. .LONG TERM...SUNDAY NIGHT THROUGH THURSDAY NIGHT IT STILL LOOKS LIKE A QUIETER WEATHER PATTERN IN THE LONG TERM THAN THE SHORT TERM. ANY LEFTOVER SNOW WITH A WEAK TRAILING SHORTWAVE WILL END SUNDAY NIGHT AS RIDGING BEGINS TO BUILD OVER THE WESTERN UNITED STATES. EXPECT ANOTHER COLD NIGHT ON SUNDAY NIGHT ALTHOUGH NOT QUITE AS COLD AS SATURDAY NIGHT. WITH A RIDGE OVER THE AREA FOR MONDAY...WE HAVE GONE WITH A DRY FORECAST FOR THE ENTIRE CWA. HIGH TEMPERATURES DO LOOK TO MODERATE JUST A BIT BUT STILL LOOK TO BE BELOW AVERAGE. MODELS THEN BEGIN TO DIVERGE JUST A BIT WITH THE EUROPEAN HAVING A SOMEWHAT MORE AMPLIFIED RIDGE OVER THE ROCKIES AND THE GFS TRANSITIONING TO MORE OF A FLAT ZONAL PATTERN FOR THE MIDDLE OF NEXT WEEK. GFS BRINGS A BIT OF MOISTURE IN FOR TUESDAY WITH THE EURO DRY. WITH THE UNCERTAINTY WE KEPT SLIGHT CHANCE POPS ACROSS THE WESTERN MOUNTAINS WITH DRY CONDITIONS ELSEWHERE. MODELS THEN DEEPEN A TROUGH AND UPPER LEVEL LOW OFF OF THE CALIFORNIA COAST AND THEN MOVE IT INLAND FOR WEDNESDAY NIGHT INTO THURSDAY. GFS DOES BREAK OFF A PIECE OF MOISTURE FOR WESTERN WYOMING AND AGAIN THE EURO IS DRY. FOR NOW WE KEPT THE LIGHT CHANCE TO CHANCE POPS ACROSS THE WEST FOR WEDNESDAY AND WEDNESDAY NIGHT. TEMPERATURES ARE ALSO UNCERTAIN DEPENDING ON WHICH MODEL VERIFIES...SO FOR NOW WE ONLY MADE SLIGHT TWEAKS. && .AVIATION.../06Z ISSUANCE/ WEST OF THE CONTINENTAL DIVIDE...A STORM SYSTEM WILL IMPACT WESTERN WY WITH RAIN CHANGING TO SNOW BY 15Z. VFR CONDITIONS WILL BECOME MVFR TO IFR BETWEEN 15Z AND 18Z AND THESE CONDITIONS WILL PREVAIL THROUGH 06Z SATURDAY. THIS INCLUDES THE KJAC...KBPI...KPNA TERMINAL SITES. EXPECT MOUNTAINS TO BE FREQUENTLY OBSCURED TODAY INTO THE EVENING HOURS. WEATHER CONDITIONS ARE LIKELY TO CHANGE QUICKLY ACROSS THE REGION AS THIS STORM MOVES THROUGH THIS MORNING AND AFTERNOON. BE SURE TO CHECK FOR THE LATEST TERMINAL FORECASTS. EAST OF THE DIVIDE...VFR CONDITIONS WILL OCCUR OVER MOST AREAS THROUGH 00Z SATURDAY. LOW CLOUDS OVER FAR NORTHERN WY WILL PRODUCE MVFR TO IFR CONDITIONS...INCLUDING THE KCOD TERMINAL SITE. AFTER 00Z SATURDAY CLOUDS WILL LOWER IN MANY LOCATIONS AND PRECIPITATION WILL INCREASE IN COVERAGE EAST OF THE DIVIDE. MVFR TO IFR CONDITIONS WILL DEVELOP AND PREVAIL THROUGH 06Z SATURDAY. EXPECT MOUNTAINS TO BE FREQUENTLY OBSCURED AFTER 00Z THROUGH 06Z SATURDAY. WEATHER CONDITIONS ARE LIKELY TO CHANGE QUICKLY ACROSS THE REGION AS THIS STORM MOVES THROUGH IN THE LATE AFTERNOON AND EVENING HOURS. BE SURE TO CHECK FOR THE LATEST TERMINAL FORECASTS. && .FIRE WEATHER... SNOW AND WIND WILL SPREAD ACROSS THE WEST TONIGHT...WITH INCREASING SOUTHWEST WINDS ALONG AND EAST OF THE CONTINENTAL DIVIDE. SNOWFALL OF 6 TO 12 INCHES IN THE MOUNTAINS WITH 3 TO 6 INCHES IN THE VALLEYS CAN BE EXPECTED BY FRIDAY EVENING. HIGH WINDS ARE POSSIBLE FRIDAY AFTERNOON AND EVENING ACROSS EASTERN SWEETWATER... SOUTHERN FREMONT AND NATRONA COUNTIES. THE CHANCE OF SNOW WILL SHIFT TO THE NORTH AND EAST FRIDAY EVENING THROUGH SATURDAY AS A STRONG COLD FRONT WILL PUSHES SOUTH FROM MONTANA WITH MUCH COLDER TEMPERATURES FOR THE WEEKEND. && .RIW WATCHES/WARNINGS/ADVISORIES... HIGH WIND WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING WYZ019-020-030. WINTER WEATHER ADVISORY FROM 2 AM FRIDAY TO 2 AM MST SATURDAY WYZ001-002-012>015-023-024-027. && SHORT TERM...C.BAKER LONG TERM...HATTINGS AVIATION...AR FIRE WEATHER...C.BAKER
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 247 PM MST THU NOV 8 2012 WYZ001>020-022>030-091400- 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- 247 PM MST THU NOV 8 2012 ...WINTER WEATHER ADVISORY LATE TONIGHT THROUGH LATE FRIDAY NIGHT FOR THE WESTERN MOUNTAINS AND VALLEYS... ...HIGH WIND WATCH EASTERN SWEETWATER...SOUTHERN FREMONT AND NATRONA COUNTIES FRIDAY AFTERNOON AND EVENING... .DAY ONE...TODAY AND TONIGHT RAIN AND SNOW DEVELOPING IN THE NORTHWEST TODAY...CHANGING TO ALL SNOW AND SPREADING ACROSS WESTERN WYOMING TONIGHT. STRONG WINDS POSSIBLE SOUTH TODAY. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY FRIDAY...SNOW IN THE WEST...SIGNIFICANT ACCUMULATIONS EXPECTED. RAIN...CHANGING TO SNOW SPREADING SOUTHEAST ACROSS CENTRAL WYOMING WITH SIGNIFICANT ACCUMULATIONS POSSIBLE FRIDAY NIGHT. HIGH WINDS POSSIBLE SOUTHERN AND CENTRAL WYOMING FRIDAY AFTERNOON AND EVENING. SATURDAY AND SUNDAY...MUCH COLDER. SNOW TAPERING OFF THROUGH THE DAY SATURDAY AND SATURDAY NIGHT.. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY AND TONIGHT. TEAM RIVERTON
The national radar mosaic for the moment the first event began.
3 winter storm. Local standard time, as filed.
A trained spotter reported 10 inches of snow 3 miles SE of Bedford.
A trained spotter reported 6.5 inches of snow 1 mile SSW of Thermopolis.
A trained spotter reported 7.6 inches of snow 16 miles SSE of Ten Sleep.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2012Every state in 2012This day in weather historyWarnings in Wyoming, November 2012
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: 414708, 416232, 414707.