An upper-level disturbance crossed western and central Wyoming during the morning and afternoon of Sunday, October 11. The combination of strong mid-level winds mixing to the surface and a tight pressure gradient produced high wind in central Wyoming and in the Absaroka Range and adjacent Cody Foothills.
Every event with a place to put it; 5 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.
An upper-level disturbance crossed western and central Wyoming during the morning and afternoon of Sunday, October 11. The combination of strong mid-level winds mixing to the surface and a tight pressure gradient produced high wind in central Wyoming and in the Absaroka Range and adjacent Cody Foothills. The highest wind gusts occurred in the Absarokas where a wind gust of 80 mph was recorded on Chief Joseph Pass. Peak gusts in the lower elevations topped-out between 58 and 65 mph.
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 Oct 10, 10:45 PM MST, 1 hour 25 minutes earlier.
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</html>HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 1228 PM MDT SAT OCT 10 2015 WYZ001>020-022>030-111830- YELLOWSTONE NATIONAL PARK-ABSAROKA MOUNTAINS-CODY FOOTHILLS- NORTH BIG HORN BASIN-SOUTHWEST BIG HORN BASIN- SOUTHEAST BIG HORN BASIN-OWL CREEK AND BRIDGER MOUNTAINS- BIGHORN MOUNTAINS WEST-BIGHORN MOUNTAINS SOUTHEAST- NORTHEAST JOHNSON COUNTY-SOUTHEAST JOHNSON COUNTY- TETON AND GROS VENTRE MOUNTAINS-JACKSON HOLE- WIND RIVER MOUNTAINS WEST-WIND RIVER MOUNTAINS EAST- UPPER WIND RIVER BASIN-WIND RIVER BASIN-LANDER FOOTHILLS- GREEN MOUNTAINS AND RATTLESNAKE RANGE- NATRONA COUNTY LOWER ELEVATIONS-CASPER MOUNTAIN-STAR VALLEY- SALT RIVER AND WYOMING RANGES-UPPER GREEN RIVER BASIN FOOTHILLS- UPPER GREEN RIVER BASIN-SOUTH LINCOLN COUNTY- ROCK SPRINGS AND GREEN RIVER-FLAMING GORGE-EAST SWEETWATER COUNTY- 1228 PM MDT SAT OCT 10 2015 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF WY...CENTRAL WYOMING...NORTH CENTRAL WYOMING...NORTHWEST WYOMING...SOUTH CENTRAL WYOMING...SOUTHWEST WYOMING AND WEST CENTRAL WYOMING. ...RED FLAG WARNING IN EFFECT FROM NOON TODAY TO 9 PM MDT FOR THE GREEN AND RATTLESNAKE RANGES AND NATRONA COUNTY AND AGAIN SUNDAY UNTIL 7 PM MDT ACROSS NATRONA COUNTY... ...HIGH WIND WATCH IN EFFECT FROM LATE TONIGHT THROUGH SUNDAY EVENING ACROSS PORTIONS OF CENTRAL WYOMING... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...THIS AFTERNOON AND TONIGHT EXTREME FIRE DANGER ACROSS PORTIONS OF CENTRAL WYOMING INCLUDING THE GREEN MOUNTAINS AND RATTLESNAKE RANGES AND NATRONA COUNTY. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY SUNDAY...EXTREME FIRE DANGER ACROSS PORTIONS OF CENTRAL WYOMING INCLUDING NATRONA COUNTY. STRONG WINDS LIKELY ACROSS MOST OF THE FORECAST AREA. HIGH WINDS POSSIBLE ALONG THE LANDER FOOTHILLS INCLUDING THE CITY OF LANDER AND NEAR THE GREEN AND RATTLESNAKE MOUNTAINS INCLUDING JEFFREY CITY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED.
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</html>The national radar mosaic for the moment the first event began.
5 high wind. Local standard time, as filed.
The RAWS sensors at Camp Creek and Fales Rock recorded wind gusts of 61 and 65 mph, respectively. Another anemometer on Beaver Rim measured a 60 mph gust around 1000MST.
The wind sensor along Chief Joseph reported several wind gusts past 74 mph including a maximum of 80 mph.
The wind sensor at Twenty Mile Hill recorded a wind gust to 58 mph. The WYDOT anemometer on Wyoming Boulevard on the south side of Casper measured a gust to 65 mph at 0841MST.
The Lander Hunt Field ASOS recorded a peak wind to 59 mph.
A wind sensor 5 miles west-northwest of Clark reported a wind gust to 64 mph.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2015Every state in 2015This day in weather historyWarnings in Wyoming, October 2015
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 2026-10-01. Each event’s entry at NCEI: 602415, 602413, 602416, 605873, 602414.