High winds developed across portions of central and southern Wyoming ahead of an advancing cold front. Sustained winds of 40 mph and wind gusts of 58 mph to 65 mph were common in a region from eastern Sweetwater County to western Natrona County.
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.
High winds developed across portions of central and southern Wyoming ahead of an advancing cold front. Sustained winds of 40 mph and wind gusts of 58 mph to 65 mph were common in a region from eastern Sweetwater County to western Natrona County.
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 9, 10:22 AM MST, 48 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 1022 AM MST FRI NOV 9 2012 .SHORT TERM...TODAY THROUGH SUNDAY NIGHT MOISTURE FROM THE APPROACHING AREA OF LOW PRESSURE HAS BEGUN TO MOVE INTO WESTERN WYOMING...WITH SNOWFALL CONTINUING TO SPREAD ACROSS THE MOUNTAINS. SNOWFALL WILL REMAIN OVER THE AREA THROUGHOUT THE DAY UNDER THE INFLUENCE OF THE WAVE OF LOW PRESSURE. MODERATE SNOWFALL ACCUMULATIONS ARE ANTICIPATED...WITH A WINTER WEATHER ADVISORY IN EFFECT FOR THE WESTERN MOUNTAINS AND VALLEYS. THE HEAVIEST SNOWFALL APPEARS MOST FAVORABLE BEFORE NOON TODAY WITH SNOWFALL RATES OF 2 INCHES AN HOUR OR MORE. SNOWFALL RATES OF AN INCH AN HOUR WILL CONTINUE THROUGH THE DAY. TODAY AND TONIGHT WILL HAVE THE HIGHEST IMPACT WITH 6 TO 10 INCHES OF SNOWFALL IN THE MOUNTAINS AND 2 TO 5 INCHES POSSIBLE IN THE BASINS. SNOWFALL INTENSITY EXPECTED TO WEAKEN LATE TONIGHT...THOUGH LIGHT SNOWFALL WILL CONTINUE THROUGHOUT SATURDAY ACROSS THE AREA. SNOWFALL WILL SPILL EAST OF THE DIVIDE THIS AFTERNOON...WITH WIDESPREAD COVERAGE ANTICIPATED BY THIS EVENING. PERIODS OF HEAVIER SNOWFALL ARE EXPECTED OVER THE BIGHORN MOUNTAINS THIS AFTERNOON AND INTO THE EVENING HOURS. A WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR THIS AREA. MODELS INDICATE THE POTENTIAL FOR THE DEVELOPMENT OF VERY STRONG WIND ACROSS THE WIND CORRIDOR AREA THIS AFTERNOON. UPPER LEVEL WIND IN EXCESS OF 50 KTS HAS BEEN SUGGESTED ON RECENT MODEL SOLUTIONS. IT IN ANTICIPATED THAT THIS STRONG WIND WILL IMPACT THE AREA...AND A HIGH WIND WARNING IS IN EFFECT THROUGH THE EVENING HOURS FOR THE DEVELOPMENT OF THIS WIND. DURING THE LATER AFTERNOON AND EARLY EVENING HOURS...IT IS POSSIBLE THAT THE COMBINATION OF STRONG WIND WITH SNOWFALL WILL CREATE HAZARDOUS TRAVEL CONDITIONS. CONDITIONS WILL BE MONITORED WITH PUBLIC UPDATES EXPECTED THROUGH THE DAY. THE AXIS OF THE WAVE OF LOW PRESSURE WILL THEN APPROACH THE AREA SATURDAY AFTERNOON AND EVENING...HELPING TO MOVE PRECIPITATION FURTHER EAST. AN APPROACHING RIDGE OF HIGH PRESSURE IS THEN ANTICIPATED BY SUNDAY. HOWEVER...MODELS DO INDICATE THE PRESENCE OF SOME WRAP AROUND MOISTURE AS THE AREA OF LOW PRESSURE MOVES FURTHER EAST. THIS WILL KEEP SOME LIGHT SNOWFALL ACROSS AREA THE WESTERN MOUNTAINS THROUGH THE REMAINDER OF THE WEEKEND. THE MILD TEMPERATURES WILL BE REPLACED WITH MUCH COOLER VALUES TODAY...WITH WIDESPREAD COOLER TEMPERATURES EXPECTED BY SATURDAY. COLDER TEMPERATURES WILL PERSIST THROUGH SUNDAY. .LONG TERM...MONDAY THROUGH FRIDAY FLAT RIDGE IS STILL FORECAST TO MOVE INTO THE AREA MONDAY INTO TUESDAY WITH MODERATING TEMPERATURES. THIS LOOKS TO BE A DIRTY RIDGE WITH PERIODS OF MID AND HIGH CLOUDS POTENTIALLY AFFECTING THE TEMPERATURES. WE DO HAVE SOME VERY SMALL POPS IN THE WESTERN MOUNTAINS MONDAY NIGHT AND TUESDAY BUT THEY'VE BEEN TONED DOWN FROM THE MEDIUM RANGE PROCEDURE AND CONFIDENCE LOW THAT THERE WILL BE ANYTHING UNDER THE RIDGE. ODDS INCREASE SOME TUESDAY NIGHT THROUGH WEDNESDAY OF PCPN IN THE FAR WEST AS TROUGH DIGS ALONG THE WEST COAST AND SOME INCREASE IN MOISTURE...MID LEVEL FRONT AND JET STREAK DYNAMICS COULD POTENTIALLY COME INTO PLAY. THE ECMWF HOWEVER...DEVELOPS THIS TROUGH OFFSHORE WITH MORE OF AN INFLUENCE FROM THE NRN STREAM. SO KEEPING THE POPS LOW FOR NOW AND SEE IF WE HAVE BETTER AGREEMENT TONIGHT. THE GFS THEN PUSHES THIS TROUGH WELL TO OUR SOUTH THURSDAY INTO THURSDAY NIGHT WITH JUST A WEAKER TROUGH PASSAGE FURTHER NORTH. THE ECMWF IS 12-18 HOURS SLOWER AND WEAKER WITHOUT MUCH OF A NRN EXTENSION OF THESE TROUGH. JUST KEEPING LOW POPS IN THE MOUNTAINS FOR NOW. && .AVIATION.../18Z ISSUANCE/ WEST OF THE CONTINENTAL DIVIDE...A STORM SYSTEM WILL IMPACT WESTERN WY TODAY WITH SNOW AND RAIN CHANGING TO SNOW. 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. THEN CONDITIONS WILL IMPROVE IN SOME AREAS AFTER 06Z SATURDAY. 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. HOWEVER...THE WILL BE STRONG AND GUSTY WINDS AT KRIW...KCPR AND KLND WITH GUSTS OVER 40 KNOTS POSSIBLE. LOW CLOUDS OVER FAR NORTHERN WY WILL PRODUCE MVFR TO IFR CONDITIONS...INCLUDING THE KCOD AND KWRL TERMINAL SITES. AFTER 00Z CLOUDS WILL LOWER AND PRECIPITATION WILL INCREASE IN COVERAGE EAST OF THE DIVIDE. MVFR TO IFR CONDITIONS WILL DEVELOP AND PREVAIL THROUGH 12Z SATURDAY. EXPECT MOUNTAINS TO BE FREQUENTLY OBSCURED AFTER 00Z THROUGH 12Z 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... A REMINDER OF WINTER WEATHER IS EXPECTED OVER THE NEXT COUPLE DAYS. SNOWFALL WILL BE FOUND OVER THE WESTERN MOUNTAINS AND VALLEYS TODAY...WITH MODERATE SNOWFALL ACCUMULATIONS EXPECTED. PLEASE VISIT OUR WINTER WEATHER HIGHLIGHT PRODUCTS FOR ADDITIONAL INFORMATION ON INTENSITY AND TIMING. MEANWHILE...STRONG WIND WILL DEVELOP ACROSS THE CORRIDOR BETWEEN ROCK SPRINGS AND CASPER THIS AFTERNOON. A HIGH WIND WARNING IS IN EFFECT FOR THIS AREA. COOLING TEMPERATURES EXPECTED TODAY...WITH SIGNIFICANTLY COOLER TEMPERATURES ANTICIPATED OVER THE WEEKEND. && .RIW WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING FROM 11 AM THIS MORNING TO 8 PM MST THIS EVENING WYZ019-020-030. WINTER WEATHER ADVISORY UNTIL 2 AM MST SATURDAY WYZ001-002-012>015-023-024-027. WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO 5 AM MST SATURDAY WYZ008-009. && SHORT TERM...BRANHAM LONG TERM...SKRBAC AVIATION...AR FIRE WEATHER...BRANHAM
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 316 AM MST FRI NOV 9 2012 WYZ001>020-022>030-101200- 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- 316 AM MST FRI NOV 9 2012 ...WINTER WEATHER ADVISORY THROUGH LATE TONIGHT FOR THE WESTERN MOUNTAINS AND VALLEYS... ...WINTER WEATHER ADVISORY THIS MORNING THROUGH THE OVERNIGHT HOURS FOR THE BIGHORN MOUNTAINS... ...HIGH WIND WARNING EASTERN SWEETWATER...SOUTHERN FREMONT AND NATRONA COUNTIES TODAY... .DAY ONE...TODAY AND TONIGHT ONGOING SNOWFALL ACROSS WESTERN WYOMING WILL RESULT IN SIGNIFICANT ACCUMULATIONS THROUGH THE DAY. A WINTER WEATHER ADVISORY IS IN EFFECT THROUGH THE OVERNIGHT HOURS. SNOWFALL WILL SPREAD EAST THROUGH THE DAY...WITH SIGNIFICANT SNOWFALL ALSO POSSIBLE OVER THE BIGHORN MOUNTAINS THIS AFTERNOON AND OVERNIGHT. A WINTER WEATHER ADVISORY IS ALSO IN EFFECT FOR THIS AREA. ADDITIONALLY...STRONG WIND IS EXPECTED TO DEVELOP BETWEEN ROCK SPRINGS AND CASPER THIS AFTERNOON. THIS STRONG WIND WILL CONTINUE INTO THE EVENING HOURS. A HIGH WIND WARNING IS IN EFFECT. AREAS OF FOG WILL SHARPLY REDUCE THE VISIBILITY THIS MORNING ACROSS THE HIGHER TERRAIN THROUGH THE BIGHORN BASIN...ALONG THE CODY FOOTHILLS AND OVER SOUTH PASS. PLEASE VISIT THE APPROPRIATE HIGHLIGHT PRODUCT FOR INFORMATION ON SNOWFALL AND WIND. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH WEDNESDAY SATURDAY AND SUNDAY...MUCH COLDER. SNOW TAPERING OFF THROUGH THE DAY SATURDAY AND SATURDAY NIGHT.. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT SNOWFALL AND WIND STRONGER THAN 50 MPH TODAY. THANK YOU. TEAM RIVERTON
The national radar mosaic for the moment the first event began.
3 high wind. Local standard time, as filed.
Winds gusted between 58 and 65 mph at Fales Rock.
An average wind speed of 40 mph was recorded from 11 a.m. to Noon MST at Hiland.
Several wind gusts to 58 mph were reported at Tipton.
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: 412968, 412969, 412970.