Several thunderstorms formed in the southern Big Horn Basin during the afternoon hours. One storm produced wind damage in the town of Worland while a second storm brought severe wind gusts to the Worland airport.
Every event with a place to put it. 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.
Several thunderstorms formed in the southern Big Horn Basin during the afternoon hours. One storm produced wind damage in the town of Worland while a second storm brought severe wind gusts to the Worland airport.
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 Jul 3, 1:36 PM MST, 44 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 236 PM MDT SUN JUL 3 2011 .SHORT TERM...TONIGHT THROUGH WEDNESDAY STORMS ARE BEGINNING TO DEVELOP ACROSS SOUTHERN SWEETWATER COUNTY...ALONG THE SOUTHERN EDGE OF ABSAROKA MOUNTAINS AND ACROSS THE BIG HORN BASIN THIS AFTERNOON IN RESPONSE TO A SHORTWAVE MOVING THROUGH MONTANA. PLENTY OF INSTABILITY PRESENT THIS AFTERNOON...WHICH WAS AIDED BY STRONG DAYTIME HEATING. A COUPLE STRONGER STORMS MAY BE POSSIBLE INTO THE EVENING HOURS TONIGHT. HAIL AND GUSTY WIND ARE EXPECTED TO BE THE PRIMARY THREATS TODAY. THE AREA OF HIGH PRESSURE WHICH HAS BEEN BRINGING THE HOT TEMPERATURES ACROSS THE AREA WILL LINGER INTO MONDAY. HOWEVER...SLIGHTLY COOLER TEMPERATURES EXPECTED ACROSS THE AREA TOMORROW AS MONSOONAL MOISTURE BEGINS TO IMPACT THE AREA WITH SLIGHTLY INCREASED CLOUD COVER. PRECIPTABLE WATERS WILL INCREASE THROUGH MONDAY AFTERNOON... WITH FAVORABLE TOTAL TOTALS AND CAPE...INDICATING THE CONTINUED POTENTIAL FOR AFTERNOON SHOWERS AND THUNDERSTORMS...SOME OF WHICH MAY BECOME STRONG. WITH AVAILABLE MOISTURE...SOME STORMS MAY BRING PERIODS OF MODERATE TO HEAVY RAINFALL...ALONG WITH GUSTY WIND AND HAIL. MONSOONAL MOISTURE WILL CONTINUE OVER THE AREA TUESDAY. TEMPERATURES CONTINUE TO COOL SLIGHTLY...WITH ANOTHER ROUND OF AFTERNOON SHOWERS AND THUNDERSTORMS POSSIBLE. COVERAGE WILL BE MORE WIDESPREAD THAN WHAT IS EXPECTED ON MONDAY...AND MODELS INDICATE RELATIVELY STRONG INSTABILITY ACCOMPANYING SHOWER AND THUNDERSTORM DEVELOPMENT. A SIMILAR SCENARIO EXPECTED WEDNESDAY AFTERNOON. .LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY MODELS CONTINUE TO BE IN FAIRLY GOOD AGREEMENT WEDNESDAY THROUGH FRIDAY WITH THE UNSETTLED WEATHER PATTERN. THE MID AND UPPER LEVEL MOISTURE WILL COME IN SURGES DURING THIS PERIOD AND THERE WILL BE INCREASED CHANCES FOR THUNDERSTORMS WITH GUSTY WIND AND LOCALLY HEAVY RAIN. SURFACE AND NEAR SURFACE DEWPOINT VALUES WILL ALSO BE KEY TO THE RAIN POTENTIAL AND THE MODELS SEEM TO BRING IN SURGES OF THAT AS WELL WED THROUGH FRI. THE GFS MODEL MAINTAINS AN UNSETTLED SW FLOW ALOFT PATTERN SATURDAY AND NEXT SUNDAY WITH THE CHANCE OF MORE STORMS. THE ECMWF MODEL PUSHES THE BETTER MOISTURE TO THE SOUTH AND MAINLY OVER THE FAR SOUTH ZONES THOSE DAYS. THIS IS DUE TO A STRONGER WEATHER SYSTEM MOVING THROUGH SOUTHERN CANADA AND PUSHING THE RIDGE TO THE SOUTH. SOME GFSENSEMBLE MEMBERS AGREE WITH THE ECMWF. WILL SEE HOW THINGS LOOK TONIGHT. FOR NOW HAVE KEPT THE THUNDERSTORM CHANCE IN THE FORECAST SATURDAY AND NEXT SUNDAY. TEMPERATURES WILL POSE A CHALLENGE DUE TO THE CLOUD COVER AND THE EXPECTED STORM ACTIVITY. HAVE MADE MINOR CHANGES TO GOING FORECAST. MOST HIGHS WILL BE IN THE 80S TO AROUND 90 WITH 60S AND 70S FOR THE HIGH COUNTRY FROM WED THROUGH NEXT SUNDAY. && .AVIATION... A WEAK TROUGH WILL MOVE ACROSS MONTANA THIS AFTERNOON AND EVENING CLIPPING NORTHERN WYOMING. ISOLATED SHOWERS AND THUNDERSTORMS ARE EXPECTED THERE...AS WELL AS OVER THE SOUTHERN TWO THIRDS FROM MOISTURE DRAWN NORTH FROM THE FOUR CORNERS. THIS MOISTURE WILL INCREASE MONDAY AND SPREAD ACROSS THE NORTH AS WELL. EXPECT THE THUNDERSTORM COVERAGE TO INCREASE. OUTFLOW WIND GUSTS TO 45KTS ALONG WITH LIGHTNING WILL BE THE PRIMARY THREATS. SOME SMALL HAIL AND +RA IS POSSIBLE FROM STRONGER STORMS. && .FIRE WEATHER... WARM TO HOT TEMPERATURES WILL REMOVE OVER THE AREA FOR THE NEXT COUPLE OF DAYS. MONSOONAL MOISTURE WILL ELEVATE DAYTIME HUMIDITY FOR THE NEXT COUPLE DAYS. EXPECT CONTINUED AFTERNOON SHOWERS AND THUNDERSTORMS FOR THE NEXT COUPLE OF DAYS...WITH ACTIVITY LINGERING INTO THE EVENING HOURS. BOTH TUESDAY AND WEDNESDAY MAY BRING A FEW STRONGER STORMS ACROSS THE AREA...WITH GUSTY AND ERRATIC WIND POSSIBLE...ALONG WITH SMALL HAIL. THE ADDED MOISTURE MAY ALSO ALLOW PERIODS OF MODERATE TO HEAVY RAINFALL WITH ANY STORM ACTIVITY THE NEXT COUPLE DAYS. && .HYDROLOGY... SOME RIVERS HAVE DECREASED TODAY...THOUGH OTHERS ACROSS THE AREA REMAIN VERY HIGH. EVEN THOSE RIVERS WHICH HAVE DECREASED REMAIN AT LEVELS WARRANTING CAUTION FOR NEARBY RESIDENTS. HOT TEMPERATURES TODAY ACROSS THE AREA WILL RESULT IN ADDITIONAL SNOW MELT...SO AREA HYDROLOGY PRODUCTS REMAIN IN EFFECT. PLEASE VIEW THESE PRODUCTS TO VIEW SPECIFIC TIMING AND DETAILS RELATING TO POTENTIAL FLOODING ACROSS CENTRAL AND WESTERN WYOMING. && .RIW WATCHES/WARNINGS/ADVISORIES... NONE. && SHORT TERM...BRANHAM LONG TERM...AR AVIATION...TWB FIRE WEATHER...BRANHAM HYDROLOGY...BRANHAM
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 400 AM MDT SUN JUL 3 2011 WYZ001>020-022>030-041200- 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- 400 AM MDT SUN JUL 3 2011 ...FLOOD WARNING FOR THE WIND RIVER FROM DUBOIS TO RIVERTON AND FOR SMALLER CREEKS AND RIVERS OF BIG HORN...SUBLETTE...AND PARK COUNTIES... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EVENING...MAINLY ACROSS MOUNTAINOUS AREAS. GUSTY WIND WILL BE THE PRIMARY THREAT WITH ANY THUNDERSTORMS. EXCESSIVE SNOWMELT DUE TO WARM TEMPERATURES WILL CONTINUE TO CAUSE HIGH WATER LEVELS ON THE WIND RIVER FROM FROM DUBOIS THROUGH RIVERTON. FLOODING WILL CONTINUE IN LOW LYING AREAS ADJACENT TO THE WIND RIVER. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY CREEKS AND RIVERS WILL CONTINUE TO RUN HIGH AND SWIFT THROUGH AT LEAST TUESDAY AS THE HIGH MOUNTAIN SNOWPACK CONTINUES TO MELT. THE WIND RIVER...SHOSHONE RIVER...GREYBULL RIVER...GREEN RIVER...BLACKS FORK RIVER...NORTH FORK OF THE POPO AGIE...AND THE BIG HORN RIVER WILL BE MOST SUSCEPTIBLE TO THE HIGH RUNOFF. EXERCISE CAUTION NEAR FAST FLOWING RIVERS AS THE CURRENT WILL BE DANGEROUS AND DEBRIS WILL BE FLOWING IN THE CHANNEL. THUNDERSTORM COVERAGE WILL BE ON THE INCREASE FROM MONDAY THROUGH AT LEAST THURSDAY AS THE WEATHER PATTERN CHANGES TO A MORE UNSETTLED SCENARIO. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT SEVERE WEATHER AND FLOODING TO THE NATIONAL WEATHER SERVICE AT 1-800-211-1448. THANK YOU. TEAM RIVERTON
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 136 PM MDT SUN JUL 3 2011 WYZ029-030-032130- EAST SWEETWATER COUNTY-FLAMING GORGE- 136 PM MDT SUN JUL 3 2011 SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE DEVELOPING OVER THE SOUTHERN HALF OF SWEETWATER COUNTY THIS AFTERNOON. THEY ARE GENERALLY MOVING EAST AT 10 MILES PER HOUR. THE STORMS WILL CONTINUE TO DEVELOP THROUGH THE AFTERNOON AND EVENING. EXPECT SOME LIGHTNING...WIND GUSTS TO 45 MPH AND POSSIBLY SOME BRIEF HEAVY RAIN AND MAYBE EVEN SOME PEA SIZE HAIL. THOSE ENJOYING THE OUTDOORS... INCLUDING THOSE ON FLAMING GORGE...SHOULD KEEP AN EYE TO THE SKY AND SEEK SHELTER IF STORMS APPROACH. TWB
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 202 PM MDT SUN JUL 3 2011 WYZ005-007-032100- OWL CREEK AND BRIDGER MOUNTAINS-SOUTHWEST BIG HORN BASIN- 202 PM MDT SUN JUL 3 2011 SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE DEVELOPING OVER THE SOUTHEAST ABSAROKAS...AND MOVING EAST AT 10 MPH INTO THE GRASS CREEK AREA THIS AFTERNOON. THE STORMS WILL CONTINUE TO DEVELOP THROUGH THE AFTERNOON AND EVENING...LIKELY SPREADING ELSEWHERE ACROSS HOT SPRINGS COUNTY. EXPECT SOME LIGHTNING...WIND GUSTS TO 45 MPH AND POSSIBLY SOME BRIEF HEAVY RAIN AND MAYBE EVEN SOME PEA SIZE HAIL. THOSE ENJOYING THE OUTDOORS...SHOULD KEEP AN EYE TO THE SKY AND SEEK SHELTER IF STORMS APPROACH. TWB
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 213 PM MDT SUN JUL 3 2011 WYZ005-007-032100- OWL CREEK AND BRIDGER MOUNTAINS-SOUTHWEST BIG HORN BASIN- 213 PM MDT SUN JUL 3 2011 SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE DEVELOPING OVER THE SOUTHEAST ABSAROKAS...AND MOVING EAST AT 25 MPH ACROSS THE GRASS CREEK AREA THIS AFTERNOON. THE STORMS WILL CONTINUE TO DEVELOP THROUGH THE AFTERNOON AND EVENING...LIKELY SPREADING ELSEWHERE ACROSS HOT SPRINGS COUNTY. EXPECT SOME LIGHTNING...WIND GUSTS TO 45 MPH AND POSSIBLY SOME BRIEF HEAVY RAIN AND MAYBE EVEN SOME PEA SIZE HAIL. THOSE ENJOYING THE OUTDOORS...SHOULD KEEP AN EYE TO THE SKY AND SEEK SHELTER IF STORMS APPROACH. TWB
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 317 PM MDT SUN JUL 3 2011 WYZ005-007-032230- OWL CREEK AND BRIDGER MOUNTAINS-SOUTHWEST BIG HORN BASIN- 317 PM MDT SUN JUL 3 2011 SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE TO MOVE OFF THE SOUTHEAST ABSAROKAS...AND INTO THE GRASS CREEK AREA THIS AFTERNOON. EXPECT SOME LIGHTNING...WIND GUSTS TO 45 MPH AND POSSIBLY SOME BRIEF HEAVY RAIN AND MAYBE EVEN SOME PEA SIZE HAIL. THOSE ENJOYING THE OUTDOORS...SHOULD KEEP AN EYE TO THE SKY AND SEEK SHELTER IF STORMS APPROACH. WYZ020-032230- NATRONA COUNTY LOWER ELEVATIONS- 317 PM MDT SUN JUL 3 2011 ISOLATED SHOWERS AND THUNDERSTORMS WILL MOVE WEST TO EAST AT 25 MPH ACROSS NATRONA COUNTY...INCLUDING THE CASPER AREA THIS AFTERNOON. EXPECT SOME LIGHTNING...WIND GUSTS TO 45 MPH AND POSSIBLY SOME BRIEF HEAVY RAIN AND MAYBE EVEN SOME PEA SIZE HAIL. THOSE ENJOYING THE OUTDOORS...INCLUDING THOSE ON AREA LAKES AND RESERVOIRS...SHOULD KEEP AN EYE TO THE SKY AND SEEK SHELTER IF STORMS APPROACH. WYZ028>030-032230- EAST SWEETWATER COUNTY-FLAMING GORGE-ROCK SPRINGS AND GREEN RIVER- 317 PM MDT SUN JUL 3 2011 SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO MOVE WEST TO EAST AT 25 MPH ACROSS THE SOUTHERN HALF OF SWEETWATER COUNTY THIS AFTERNOON. EXPECT SOME LIGHTNING...WIND GUSTS TO 45 MPH AND POSSIBLY SOME BRIEF HEAVY RAIN AND MAYBE EVEN SOME PEA SIZE HAIL. THOSE ENJOYING THE OUTDOORS...INCLUDING THOSE ON FLAMING GORGE... SHOULD KEEP AN EYE TO THE SKY AND SEEK SHELTER IF STORMS APPROACH. TWB
The Riverton/Lander radar (KRIW), 114 km away, was scanning. The volume nearest the first event began at 21:18 UTC.
2 thunderstorm wind. Local standard time, as filed.
Thunderstorm outflow wind toppled 15 to 20 power poles in the town of Worland. A fence at the Bureau of Land Management office was also blown over.
The automated observing station at Worland Municipal Airport recorded a 62 mph wind gust associated with a strong thunderstorm in the area.
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: 326042, 326045.