Strong winds aloft and a tight surface pressure gradient produced strong and gusty southwest winds along the Interstate 25 and 80 wind corridors in southeast Wyoming.
Every event with a place to put it; 8 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 CYS wrote it up.
Strong winds aloft and a tight surface pressure gradient produced strong and gusty southwest winds along the Interstate 25 and 80 wind corridors in southeast Wyoming.
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 Cheyenne, WY wrote its last area forecast discussion before the first event at Nov 22, 2:05 AM MST, 10 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHEYENNE WY 205 AM MST TUE NOV 22 2011 .SHORT TERM...TODAY THROUGH THURSDAY...QUIET WEATHER EXPECTED THIS WEEK AS MODELS CONTINUE TO SHOW A RIDGE OF HIGH PRESSURE BUILDING INTO THE CENTRAL AND NORTHERN ROCKIES AND GREAT PLAINS. CURRENT KCYS RADAR LOOP CONTINUES TO SHOW SOME LIGHT SNOW SHOWERS ACROSS THE HIGHER PEAKS OF THE SNOWY AND SIERRA MADRE RANGE EARLY THIS MORNING AS A QUICK MOVING UPPER LEVEL TROUGH PUSHES EASTWARD INTO THE CENTRAL AND SOUTHERN PLAINS. EXPECT SKIES TO CLEAR IN THE NEXT FEW HOURS AS DRIER AIR AND SUBSIDENCE IMPACT THE AREA TODAY. THE ONLY MINOR FORECAST CONCERN THROUGH THURSDAY IS GUSTY WINDS ACROSS SOUTHEAST WYOMING...ESPECIALLY ACROSS THE WIND PRONE AREAS ALONG I25 AND I80. WIND GUSTS FROM THE WEST OR SOUTHWEST OF 55 MPH ARE LIKELY TODAY...AND WEDNESDAY/THURSDAY MORNING BETWEEN RAWLINS AND LARAMIE...AND ALSO NORTH OF CHEYENNE NEAR WHEATLAND. GUSTS UP TO 45 MPH ARE POSSIBLE OUTSIDE THESE WIND PRONE AREAS TODAY...WITH WINDS WEAKENING SLIGHTLY INTO THURSDAY. TEMPERATURES WILL WARM INTO THE UPPER 50S AND 60S EAST OF THE LARAMIE RANGE AS A RESULT OF THE WARM DOWNSLOPE WINDS WEDNESDAY AND THURSDAY...WITH 40S AND LOW 50S WEST OF THE LARAMIE RANGE. LOW TEMPERATURES WILL BE RELATIVELY MILD AS WELL...EXCEPT FOR THE MORE SHELTERED VALLEYS WHICH WILL REMAIN IN THE 20S. KEPT POP NEAR ZERO INTO THURSDAY BUT INCREASED WINDS IN THE WIND PRONE AREAS. .LONG TERM...THURSDAY NIGHT THROUGH MONDAY... OUT OF PHASE UPPER TROF WILL SWING ACROSS THE NORTHERN AND SOUTHERN ROCKYS LATE THURSDAY NIGHT AND FRIDAY WITH THE CWA SEEING THE EFFECTS MAINLY FROM THE NORTHERN SYSTEM. AN INITIAL COOL FRONT WILL SWEEP ACROSS THE CWA EARLY FRIDAY WITH A STRONGER PUSH OF COOLER AIR MOVING IN FRIDAY NIGHT ALONG WITH WIDELY SCATTERED SNOW SHOWERS...MOST NUMEROUS OVER THE MTNS. CLEARING AND COOL WEATHER FOR SATURDAY THEN WARMING SUNDAY AS UPPER RIDGE BUILDS AND MOVES ACROSS THE REGION. RIDGE THEN WEAKENS NEXT MONDAY AS NEXT SHORTWAVE MOVES OVER THE PACIFIC NW INTO THE NORTHERN ROCKYS. GFS STRONGER WITH THIS SYSTEM WHILE LATEST ECMWF SOMEWHAT FLATTER. WILL LEAN TOWARDS THE WEAKER ECMWF SOLUTION FOR NOW WITH SOME MINOR COOLING FOR MONDAY ALONG WITH QUITE BREEZY CONDITIONS. && .AVIATION...12Z TAFS... VFR OVER ALL TERMINALS TODAY AND TONIGHT WITH SOME HIGH CLOUDS PASSING ACROSS. SOME HIGHER MTN OBSCURATION MAINLY THIS MORNING. AREAS OF GUSTY WINDS MAINLY TODAY OVER AND NEAR THE MTNS OF SE WYOMING. && .FIRE WEATHER...WARM AND DRY CONDITIONS ARE EXPECTED THROUGH THE END OF THIS WEEK. WESTERLY WINDS WILL BE GUSTY AT TIMES THROUGH THIS WEEK AS WELL...WITH THE STRONGEST WINDS EXPECTED ON FRIDAY. HUMIDITIES ACROSS PLAINS WILL DROP TO THE LOW TO MID 20 PERCENTS FOR WEDNESDAY AND THURSDAY...WITH UPPER TEENS POSSIBLE IN THE LEE OF THE LARAMIE RANGE ACROSS SOUTHEAST WYOMING. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && SHORT TERM/FIRE WEATHER...TJT LONG TERM/AVIATION...RE
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE CHEYENNE WY 804 PM MST MON NOV 21 2011 WYZ101>119-221300- CONVERSE COUNTY LOWER ELEVATIONS-NIOBRARA COUNTY- NORTH LARAMIE RANGE-FERRIS/SEMINOE/SHIRLEY MOUNTAINS- SHIRLEY BASIN-CENTRAL LARAMIE RANGE AND SOUTHWEST PLATTE COUNTY- EAST PLATTE COUNTY-GOSHEN COUNTY-CENTRAL CARBON COUNTY- NORTH SNOWY RANGE FOOTHILLS-SOUTHWEST CARBON COUNTY- SIERRA MADRE RANGE-UPPER NORTH PLATTE RIVER BASIN-SNOWY RANGE- LARAMIE VALLEY-SOUTH LARAMIE RANGE-SOUTH LARAMIE RANGE FOOTHILLS- CENTRAL LARAMIE COUNTY-EAST LARAMIE COUNTY- 804 PM MST MON NOV 21 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL WYOMING... SOUTH CENTRAL WYOMING AND SOUTHEAST WYOMING. .DAY ONE...TONIGHT LIGHT SNOW SHOWERS WILL CONTINUE OVER THE SNOWY AND SIERRA MADRE RANGES. AN ADDITIONAL INCH OR TWO OF SNOW IS EXPECTED. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY WEST TO SOUTHWEST WINDS OF 25 TO 35 MPH WITH GUSTS UP TO 50 MPH CAN BE EXPECTED IN SOME AREAS ALONG AND WEST OF THE LARAMIE RANGE THROUGH FRIDAY. HIGHER WINDS SPEEDS WITH GUSTS APPROACHING 60 MPH WILL BE POSSIBLE FRIDAY AND FRIDAY NIGHT...WHEN THE NEXT PACIFIC COLD FRONT MOVES THROUGH. THERE WILL ALSO BE CHANCES FOR RAIN AND SNOW AT THAT TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TONIGHT. && THIS PRODUCT...ALONG WITH OTHER WEATHER...HYDROLOGIC...AND CLIMATE INFORMATION IS AVAILABLE ON THE WEB AT... HTTP://WEATHER.GOV/CHEYENNE NEZ002-003-019>021-054-055-095-096-221300- DAWES-BOX BUTTE-SCOTTS BLUFF-BANNER-MORRILL-KIMBALL-CHEYENNE- NORTH SIOUX-SOUTH SIOUX- 804 PM MST MON NOV 21 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE WESTERN NEBRASKA PANHANDLE. .DAY ONE...TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TONIGHT. && THIS PRODUCT...ALONG WITH OTHER WEATHER...HYDROLOGIC...AND CLIMATE INFORMATION IS AVAILABLE ON THE WEB AT... HTTP://WEATHER.GOV/CHEYENNE JAMSKI
The national radar mosaic for the moment the first event began.
8 high wind. Local standard time, as filed.
The WYDOT site at Arlington measured sustained winds of 40 mph or greater.
The WYDOT site at Arlington measured sustained winds of 40 mph or greater, with a peak gust of 58 mph at 22/0735L.
The WYDOT site at Foote Creek near Arlington measured sustained winds of 40 mph or greater, with a peak gust of 65 mph at 22/1326L.
The WYDOT site at Elk Mountain measured sustained winds of 40 mph or greater, with a peak gust of 60 mph at 22/1341L.
The WYDOT site at Arlington measured sustained winds of 40 mph or greater, with a peak gust of 63 mph at 22/1520L.
The WYDOT site at Vedauwoo measured sustained winds of 40 mph or greater, with a peak gust of 58 mph at 22/1527L.
The WYDOT site at Bordeaux measured sustained winds of 40 mph or greater, with a peak gust of 69 mph at 22/1515L.
The WYDOT site at Pumpkin Vine measured gusts of 58 mph.
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, November 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: 350449, 350450, 350453, 350452, 350451, 350455, 350448, 350454.