A severe thunderstorm produced small hail and wind gusts around 70 mph in the Sundance area. Heavy rain caused minor flooding of roads.
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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 UNR wrote it up.
A severe thunderstorm produced small hail and wind gusts around 70 mph in the Sundance area. Heavy rain caused minor flooding of roads.
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 Rapid City, SD wrote its last area forecast discussion before the first event at Jul 8, 7:15 PM MST, 3 hours earlier.
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 815 PM MDT FRI JUL 8 2011 .DISCUSSION...HAVE CANCELLED THE REST OF THE WATCH AS SEVERE THREAT LOOKS TO BE MINIMAL THE REST OF THIS EVE ACROSS SWRN/SCNTRL SD. && .PREV DISCUSSION... /ISSUED 714 PM MDT FRI JUL 8 2011/ DISCUSSION...SURFACE BOUNDARY EXTENDS ALONG A LINE FROM JUST WEST OF PHILIP TO NEAR OGLALA...WITH SVR THREAT MAINLY EAST OF THIS LINE SO HAVE CANCELLED THE SVR WATCH WEST/NORTH OF THE BOUNDARY. 00Z KUNR SOUNDING REVEALS A SUBSIDENCE INVERSION AROUND 500MB WHICH IS LIKELY WHY SVR STORMS HAVE NOT ERUPTED THIS AFTERNOON/EVENING. A CLUSTER OF STORMS MOVING EWD ACROSS SERN MT ARE EXPECTED TO WEAKEN BEFORE ARRIVING IN NWRN SD. PREV DISCUSSION... /ISSUED 142 PM MDT FRI JUL 8 2011/ DISCUSSION...CURRENT SURFACE MAP SHOWS TROF ALONG MT/ND BORDER INTO WRN NE. WEAK SURFACE LOW ALONG THE TROF VICINITY OF THE BLACK HILLS. SEVERE THUNDERSTORMS EXPECTED THROUGH THE EVENING WITH LARGE HAIL/DAMAGING WIND GUSTS. ISOLATED TORNADO THREAT ACROSS NW SD. MOST OF THE THUNDERSTORM ACTIVITY TO PUSH INTO CEN/ERN SD OVERNIGHT. ON SATURDAY...COLD FRONT HANGS UP ACROSS NE WY/SW SD WITH WEAK UPSLOPE FLOW NORTH OF THE FRONT. ANOTHER ROUND OF STRONG/SEVERE THUNDERSTORMS FROM BLACK HILLS INTO SC SD. UNSETTLED WEATHER CONTINUES ON SUNDAY AS MONSOONAL MOISTURE LIFTS BACK NORTH AND SHORTWAVE MOVES ALONG SD/NE BORDER. EXTENDED...PERSISTENT UNSETTLED PATTERN WILL CONTINUE NEXT WEEK AS A SERIES OF SHORT WAVES SLIDE ACROSS THE AREA...BRINGING DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS. NEAR TO SLIGHTLY ABOVE AVERAGE TEMPS ARE EXPECTED THROUGH THE PERIOD. AVIATION...SCATTERED TO NUMEROUS THUNDERSTORMS CAN BE EXPECTED INTO TONIGHT...ESPECIALLY ACROSS THE SD PLAINS. SOME STORMS WILL BE SEVERE INTO THIS EVENING AND PRODUCE BRIEF MVFR/IFR CONDITIONS. OTHERWISE...VFR CONDITIONS ARE EXPECTED INTO SATURDAY MORNING. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && JOHNSON
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RAPID CITY SD 831 PM MDT FRI JUL 8 2011 SDZ001-002-012>014-024>032-041>044-046-047-049-072>074-WYZ054>058- 071-091300- BENNETT-BUTTE-CENTRAL BLACK HILLS-CUSTER CO PLAINS-FALL RIVER-HAAKON- HARDING-HERMOSA FOOT HILLS-JACKSON-MELLETTE-NORTHEASTERN CROOK- NORTHERN BLACK HILLS-NORTHERN CAMPBELL-NORTHERN FOOT HILLS- NORTHERN MEADE CO PLAINS-PENNINGTON CO PLAINS-PERKINS-RAPID CITY- SHANNON-SOUTHERN BLACK HILLS-SOUTHERN CAMPBELL-SOUTHERN FOOT HILLS- SOUTHERN MEADE CO PLAINS-STURGIS/PIEDMONT FOOT HILLS-TODD-TRIPP- WESTERN CROOK-WESTON-WYOMING BLACK HILLS-ZIEBACH- 831 PM MDT (931 PM CDT) FRI JUL 8 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN SOUTH DAKOTA AND NORTHEASTERN WYOMING. .DAY ONE...TONIGHT A FEW THUNDERSTORMS ARE EXPECTED OVERNIGHT...BUT SEVERE STORMS ARE NOT EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY AN UNSETTLED WEATHER PATTERN WILL CONTINUE THROUGH THE WEEKEND INTO EARLY NEXT WEEK WITH DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS. ON SATURDAY...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER SOUTH CENTRAL SOUTH DAKOTA. THE MAIN THREATS FROM SEVERE STORMS ON SATURDAY WILL BE LARGE HAIL AND DAMAGING WIND GUSTS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RAPID CITY SD 542 PM MDT FRI JUL 8 2011 SDZ043-046-090030- JACKSON SD-MELLETTE SD- 542 PM MDT FRI JUL 8 2011 ...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN MELLETTE AND NORTHEASTERN JACKSON COUNTIES UNTIL 630 PM MDT/730 PM CDT/... AT 540 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 6 MILES SOUTHEAST OF KADOKA...MOVING NORTHEAST AT 15 MPH. HAIL UP TO THE SIZE OF PENNIES AND WIND GUSTS UP TO 50 MPH ARE EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN. LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE... BELVIDERE... THIS INCLUDES INTERSTATE 90 BETWEEN SOUTH DAKOTA MILE MARKERS 145 AND 174... TORRENTIAL RAIN...WHICH MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND UNDERPASSES...IS ALSO LIKELY. DO NOT DRIVE YOUR VEHICLE ON A FLOODED ROADWAY. CARSTENS
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RAPID CITY SD 833 PM MDT FRI JUL 8 2011 WYZ054-055-090315- NORTHERN CAMBELL WY-SOUTHERN CAMPBELL WY- 833 PM MDT FRI JUL 8 2011 ...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL CAMPBELL COUNTY UNTIL 915 PM MDT... AT 831 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM NEAR ECHETA...OR 22 MILES NORTHWEST OF DOWNTOWN GILLETTE...MOVING EAST AT 30 MPH. HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 40 MPH ARE EXPECTED WITH THIS STORM. LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE... DOWNTOWN GILLETTE... ECHETA... WYODAK... THIS INCLUDES INTERSTATE 90 BETWEEN WYOMING MILE MARKERS 116 AND 138... IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A STURDY BUILDING. JOHNSON
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RAPID CITY SD 914 PM MDT FRI JUL 8 2011 WYZ054-056-090400- NORTHERN CAMBELL WY-WESTERN CROOK WY- 914 PM MDT FRI JUL 8 2011 ...SIGNIFICANT WEATHER ADVISORY FOR EASTERN CAMPBELL AND SOUTHWESTERN CROOK COUNTIES UNTIL 1000 PM MDT... AT 913 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM JUST NORTH OF DOWNTOWN GILLETTE...MOVING EAST AT 30 MPH. WIND GUSTS UP TO 40 MPH ARE EXPECTED WITH THIS STORM. LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE... WYODAK... ROZET... MOORCROFT... KEYHOLE RESERVOIR... THIS INCLUDES INTERSTATE 90 BETWEEN WYOMING MILE MARKERS 122 AND 160... JOHNSON
The Rapid City radar (KUDX), 127 km away, was scanning. The volume nearest the first event began at 05:13 UTC.
2 thunderstorm wind, 1 hail. Local standard time, as filed.
Striong winds blew down large trees and fences in Sundance.
Severe trees downed by the wind.
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, July 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: 331344, 331338, 331340.