Lightning struck a haystack north of Missouri Valley eventually causing a large fire.
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.
Lightning struck a haystack north of Missouri Valley eventually causing a large fire.
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 Aug 6, 1:29 PM MST, 1 hour 56 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 229 PM MDT FRI AUG 6 2010 .SHORT TERM...TONIGHT THROUGH MONDAY TWO SHORTWAVES AND AFTERNOON HEATING HELPING WITH RAPID DEVELOPMENT OF THUNDERSTORMS ACROSS A BIG PORTION OF THE WEST...SOUTH AND NORTHEASTERN ZONES THIS AFTERNOON. HEATING IS MUCH BETTER TODAY AND LAPS ANALYSIS IS SHOWING WIDESPREAD CAPES OF 500 TO 1000 J/KG WITH LI'S OF -1 TO -2. SHOULD BE AN ACTIVE REST OF THE AFTERNOON AND EVENING AS THE WRN WYO AND NCNTRL WYO SHORTWAVES MOVE ENE ACROSS THE AREA. THUNDERSTORMS ALSO FORMING ACROSS SRN AND ERN SWEETWATER COUNTY IN WHAT APPEARS TO BE A LOW LEVEL CONVERGENT BOUNDARY. ON SATURDAY...WE MAY SEE SOME DRYING FOR THE CNTRL ZONES BUT ONE SHORTWAVE MAY AFFECT THE FAR NW AND NCNTRL SECTIONS AND THE MONSOONAL PLUME LOOKS LIKE IT WILL START SURGING NWD ALREADY AND ASSIST IN S AND SERN SWEETWATER STORMS LATE IN THE DAY ALONG WITH A 50KT SPEEDMAX. AS OUR WEST COAST TROUGH STRENGTHENS ON SUNDAY...THE FLOW BACK FURTHER AND THE SSW FLOW BECOMES INCREASING MOIST LEADING TO INCREASING THUNDERSTORM COVERAGE FROM S TO N SUNDAY INTO SUNDAY EVENING. BY MONDAY...THE TROUGH GETS KICKED OUT AND LIFTS NE ACROSS THE WEST RESULTING IN THE POTENTIAL FOR SIGNIFICANT THUNDERSTORMS MOVING FROM SW TO NE LATE SUNDAY NIGHT THROUGH THE DAY MONDAY. HAVE INCREASED POPS DURING THIS TIMEFRAME TO INDICATE THIS POTENTIAL. THE STRENGTHENING JET STREAK ON SUNDAY AND SUNDAY NIGHT MAY ALSO PROVIDE ADDITIONAL LIFT ACROSS THE CNTRL AND SRN ZONES. .LONG TERM...MONDAY NIGHT THROUGH FRIDAY GFS AND ECMWF HAVE TIMING ISSUES WITH A STRONG IMPULSE TRACKING NORTHEAST OUT OF THE SOUTHWEST UPPER TROUGH MONDAY INTO MONDAY NIGHT. GFS IS FASTER WITH THE IMPULSE THAN THE ECMWF AT 00Z TUE. HAVE USED MIDDLE OF THE ROAD TIMING AND RAISED THE CHANCE OF STORMS MOST PLACES MONDAY AFTERNOON. SYSTEM MOVES OUT MONDAY NIGHT. GFS AND ECMWF DIFFER FROM TUE THROUGH FRI WITH DETAILS OF WEATHER SYSTEMS. IT APPEARS THAT RIDGING IN THE GULF OF ALASKA/NORTHERN PACIFIC WILL ATTEMPT TO TAKE PLACE NEXT WEEK. THIS IN TURN LEADS TO A DEVELOPING TROUGH IN WESTERN AND CENTRAL CANADA. THIS IN TURNS TAKES THE SW FLOW ALOFT OVER WY AND TURNS IT WEST AND EVEN NORTHWEST BY NEXT FRIDAY. THE ECMWF DROPS A POTENT WEATHER SYSTEM INTO IDAHO WED AND ACROSS WY THURSDAY. THIS SEEMS ODD AND NOT FOLLOWED AT THIS TIME. THE GFS IS KEEPING A WEATHER SYSTEM OFF THE WEST COAST NEXT WED AND THURS. ISOLATED CONVECTION EXPECTED TUE PM AND TUE NIGHT. THEN A DRYING TREND WED THROUGH FRI WITH CONVECTION MAINLY OVER MOUNTAINS AND ALONG ADJACENT FOOTHILLS. WILL SEE HOW THINGS LOOK IN THE COMING DAYS AS TO WHETHER THIS CHANGE IN THE WEATHER PATTERN WILL OCCUR. HAVE MADE SOME CHANGES TO HIGHS AND LOWS BASED ON THE FACT THAT SOME DAYS WILL HAVE MORE CLOUDS AND COOLER TEMPS ALOFT. THE CHALLENGE WAS HOW MUCH TO COOL THE HIGHS AND LOWS ON CERTAIN DAYS. && .AVIATION... ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL REMAIN PRESENT ACROSS MUCH OF CENTRAL AND WESTERN WYOMING THROUGH 03Z THIS EVENING. SOME STORMS MAY CONTAIN HEAVY RAIN...FREQUENT LIGHTNING AND GUSTY WIND TO 40 MPH...AND MAY CREATE PERIODS OF MVFR TO IFR CONDITIONS AT AIRPORTS ACROSS THE STATE. SHOWER ACTIVITY WILL WEAKEN BETWEEN 12Z AND 18Z SATURDAY...THOUGH ANOTHER ROUND OF ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP AFTER 18Z SATURDAY. NORTHERN AND SOUTHERN WYOMING...INCLUDING KCOD...KGEY...KBYG AND KRKS WILL HAVE THE BEST OPPORTUNITY TO SEE SHOWER AND THUNDERSTORM CONDITIONS SATURDAY. AGAIN...THESE STORMS MAY CREATE BRIEF PERIODS OF MVFR TO IFR CONDITIONS...AND ANY STORM DEVELOPMENT OVER THE HIGHER TERRAINS MAY LEAVE MOUNTAIN TOPS OBSCURED THROUGH THE AFTERNOON. && .FIRE WEATHER... SCATTERED THUNDERSTORMS ARE EXPECTED ACROSS MUCH OF THE AREA INTO THE EVENING HOURS. STORMS ARE EXPECTED TO BE EVEN MORE NUMEROUS OVER THE WESTERN MOUNTAINS. SOME OF THESE STORMS MAY BE QUITE STRONG PRODUCING HAIL...STRONG WIND GUSTS...HEAVY RAIN AND FREQUENT LIGHTNING. ISOLATED TO WIDELY SCATTERED THUNDERSTORMS ARE EXPECTED AGAIN SATURDAY WITH A LITTLE BETTER COVERAGE IN SOUTHERN SWEETWATER COUNTY AND THE FAR NORTHERN MOUNTAINS. ANOTHER SURGE OF MONSOONAL MOISTURE WILL RESULT IN INCREASING THUNDERSTORM COVERAGE LATE SUNDAY INTO SUNDAY NIGHT. MINIMUM RH'S WILL DRY OUT BRIEFLY SATURDAY INTO THE TEENS TO MID 20S BUT INCREASE AGAIN ON SUNDAY 5 TO 8 PERCENT ACROSS THE SOUTH. && .RIW WATCHES/WARNINGS/ADVISORIES...NONE. && SHORT TERM...SKRBAC LONG TERM...AR AVIATION...BRANHAM FIRE WEATHER...SKRBAC
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 500 AM MDT FRI AUG 6 2010 WYZ001>020-022>030-071200- 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- 500 AM MDT FRI AUG 6 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT SCATTERED THUNDERSTORMS ARE EXPECTED TODAY AND TONIGHT OVER WESTERN AND CENTRAL WYOMING. GUSTY WINDS TO 50 MPH AND DANGEROUS LIGHTNING ARE LIKELY. VERY HEAVY RAINFALL AND SMALL TO MEDIUM SIZED HAIL ARE POSSIBLE WITH SOME OF THE STRONGER THUNDERSTORMS. THE ACTIVITY WILL DIMINISH LATE THIS EVENING...WITH ISOLATED THUNDERSTORMS LINGERING OVERNIGHT. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY ISOLATED TO SCATTERED THUNDERSTORMS WILL OCCUR MAINLY IN THE AFTERNOON AND EVENING HOURS SATURDAY THROUGH TUESDAY. ISOLATED THUNDERSTORMS COULD LINGER THROUGH THE OVERNIGHT AND MORNING HOURS. THE MAIN HAZARDS FROM THE STORMS WILL BE DANGEROUS CLOUD TO GROUND LIGHTNING...SMALL HAIL...GUSTY OUTFLOW WINDS AND LOCALLY HEAVY RAINFALL. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE REQUIRED THIS AFTERNOON AND EVENING. TEAM RIVERTON
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 250 PM MDT FRI AUG 6 2010 WYZ027>030-062200- EAST SWEETWATER COUNTY-FLAMING GORGE-ROCK SPRINGS AND GREEN RIVER- SOUTH LINCOLN COUNTY- 250 PM MDT FRI AUG 6 2010 SHOWERS AND THUNDERSTORMS ARE CURRENTLY FORMING AND MOVING NORTHEAST ACROSS THE AREA...AND WILL CONTINUE TO AFFECT THE AREA THROUGH 400 PM. THE MAIN THREATS WITH THESE STORMS ARE SMALL HAIL...OCCASIONAL DANGEROUS CLOUD TO GROUND LIGHTNING...AND GUSTY WINDS TO 50 MPH. AREAS AFFECTED INCLUDE...GREEN RIVER...ROCK SPRINGS...KEMMERER...AND INTERSTATE 80 BETWEEN GRANGER AND WAMSUTTER WYZ014-015-062200- WIND RIVER MOUNTAINS EAST-WIND RIVER MOUNTAINS WEST- 250 PM MDT FRI AUG 6 2010 SHOWERS AND THUNDERSTORMS ARE CURRENTLY FORMING AND MOVING NORTHEAST ACROSS THE AREA...AND WILL CONTINUE TO AFFECT THE AREA THROUGH 400 PM. THE MAIN THREATS WITH THESE STORMS ARE SMALL HAIL...OCCASIONAL DANGEROUS CLOUD TO GROUND LIGHTNING...AND GUSTY WINDS TO 50 MPH. AREAS AFFECTED INCLUDE...TOGWOTEE PASS...AND SOUTH PASS. WYZ025-026-062200- UPPER GREEN RIVER BASIN-UPPER GREEN RIVER BASIN FOOTHILLS- 250 PM MDT FRI AUG 6 2010 SHOWERS AND THUNDERSTORMS ARE CURRENTLY FORMING AND MOVING NORTHEAST ACROSS THE AREA...AND WILL CONTINUE TO AFFECT THE AREA THROUGH 400 PM. THE MAIN THREATS WITH THESE STORMS ARE SMALL HAIL...OCCASIONAL DANGEROUS CLOUD TO GROUND LIGHTNING...AND GUSTY WINDS TO 50 MPH. AREAS AFFECTED INCLUDE...PINEDALE...BIG PINEY...AND FARSON. WYZ023-024-062200- SALT RIVER AND WYOMING RANGES-STAR VALLEY- 250 PM MDT FRI AUG 6 2010 SHOWERS AND THUNDERSTORMS ARE CURRENTLY FORMING AND MOVING NORTHEAST ACROSS THE AREA...AND WILL CONTINUE TO AFFECT THE AREA THROUGH 400 PM. THE MAIN THREATS WITH THESE STORMS ARE SMALL HAIL...OCCASIONAL DANGEROUS CLOUD TO GROUND LIGHTNING...AND GUSTY WINDS TO 50 MPH. AREAS AFFECTED INCLUDE...ALPINE...AFTON...THAYNE...SALT RIVER PASS... AND COKEVILLE. DSB
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
258 PM MDT FRI AUG 6 2010
WYZ001-012-013-062145-
JACKSON HOLE WY-TETON AND GROS VENTRE MOUNTAINS WY-YELLOWSTONE
NATIONAL PARK WY-
258 PM MDT FRI AUG 6 2010
...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL TETON COUNTY IN NORTHWEST
WYOMING UNTIL 345 PM MDT...
AT 254 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM GIBSON MEADOWS TO
FONDA POINT CAMPGROUND TO U.S. HWY 26/89 MILE MARKER 180...AND MOVING
NORTH AT 5 MPH.
HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 40 MPH ARE
EXPECTED WITH THESE STORMS...ALONG WITH HEAVY RAIN AND FREQUENT
DANGEROUS LIGHTNING.
THESE STORMS WILL BE NEAR...
U.S. HWY 89/287 MILE MARKER 200 AND COLTER BAY VILLAGE AROUND 305 PM
MDT.
U.S. HWY 26/89 MILE MARKER 180 AROUND 320 PM MDT.
U.S. HWY 89/287 MILE MARKER 190...U.S. HWY 89/287 MILE MARKER 210...
MORAN JUNCTION AND SOUTH ENTRANCE AROUND 345 PM MDT.
IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A
STURDY BUILDING.
BRIEF HEAVY RAIN...WHICH MAY FLOOD LOW LYING AREAS SUCH AS DITCHES
AND UNDERPASSES...IS ALSO LIKELY. DO NOT DRIVE YOUR VEHICLE ON A
FLOODED ROADWAY.
REPORT HAZARDOUS WEATHER TO THE NATIONAL WEATHER SERVICE OFFICE IN
RIVERTON AT 1-800-211-1448.
LAT...LON 4445 11102 4435 11048 4408 11013 4359 11061
4394 11073 4404 11106
TIME...MOT...LOC 2058Z 201DEG 5KT 4410 11094 4402 11069
4376 11059
BRANHAMSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 323 PM MDT FRI AUG 6 2010 WYZ020-022-062230- CASPER MOUNTAIN-NATRONA COUNTY LOWER ELEVATIONS- 323 PM MDT FRI AUG 6 2010 SHOWERS AND THUNDERSTORMS ARE CURRENTLY FORMING AND MOVING NORTHEAST ACROSS THE AREA...AND WILL CONTINUE TO AFFECT THE AREA THROUGH 430 PM. THE MAIN THREATS WITH THESE STORMS ARE SMALL HAIL...OCCASIONAL DANGEROUS CLOUD TO GROUND LIGHTNING...AND GUSTY WINDS TO 50 MPH. AREAS AFFECTED INCLUDE...CASPER...HIGHWAY 220 BETWEEN CASPER AND INDEPENDENCE ROCK. AND INTERSTATE 25 BETWEEN CASPER AND MIDWEST. DSB
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 343 PM MDT FRI AUG 6 2010 WYZ002-016-062230- ABSAROKA MOUNTAINS-UPPER WIND RIVER BASIN- 343 PM MDT FRI AUG 6 2010 SHOWERS AND THUNDERSTORMS ARE CURRENTLY FORMING AND MOVING NORTHEAST ACROSS THE AREA...AND WILL CONTINUE TO AFFECT THE AREA THROUGH 430 PM. THE MAIN THREATS WITH THESE STORMS ARE SMALL HAIL...OCCASIONAL DANGEROUS CLOUD TO GROUND LIGHTNING...AND GUSTY WINDS TO 50 MPH. AREAS AFFECTED INCLUDE...DUBOIS...AND HIGHWAY 14 16 20 BETWEEN CODY AND THE EAST ENTRANCE TO YELLOWSTONE NATIONAL PARK. DSB
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 406 PM MDT FRI AUG 6 2010 WYZ028>030-062300- EAST SWEETWATER COUNTY-FLAMING GORGE-ROCK SPRINGS AND GREEN RIVER- 406 PM MDT FRI AUG 6 2010 SHOWERS AND THUNDERSTORMS ARE CURRENTLY FORMING AND MOVING NORTHEAST ACROSS THE AREA...AND WILL CONTINUE TO AFFECT THE AREA THROUGH 500 PM. THE MAIN THREATS WITH THESE STORMS ARE SMALL HAIL...OCCASIONAL DANGEROUS CLOUD TO GROUND LIGHTNING...AND GUSTY WINDS TO 50 MPH. AREAS AFFECTED INCLUDE...INTERSTATE 80 BETWEEN GRANGER AND WAMSUTTER. WYZ025-026-062300- UPPER GREEN RIVER BASIN-UPPER GREEN RIVER BASIN FOOTHILLS- 406 PM MDT FRI AUG 6 2010 SHOWERS AND THUNDERSTORMS ARE CURRENTLY FORMING AND MOVING NORTHEAST ACROSS THE AREA...AND WILL CONTINUE TO AFFECT THE AREA THROUGH 500 PM. THE MAIN THREATS WITH THESE STORMS ARE SMALL HAIL...OCCASIONAL DANGEROUS CLOUD TO GROUND LIGHTNING...AND GUSTY WINDS TO 50 MPH. AREAS AFFECTED INCLUDE...PINEDALE...BIG PINEY...AND HIGHWAY 191 BETWEEN PINEDALE AND ROCK SPRINGS. DSB
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 414 PM MDT FRI AUG 6 2010 WYZ002>004-062245- ABSAROKA MOUNTAINS WY-CODY FOOTHILLS WY-NORTH BIG HORN BASIN WY- 414 PM MDT FRI AUG 6 2010 ...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN BIG HORN COUNTY IN NORTH CENTRAL WYOMING...AND NORTHEASTERN PARK COUNTY IN NORTHWEST WYOMING UNTIL 445 PM MDT... AT 408 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM NEAR HWY JCT 296 AND 120...OR 15 MILES NORTH OF CODY...MOVING NORTHEAST AT 40 MPH. WIND GUSTS UP TO 50 MPH ARE EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN AND FREQUENT DANGEROUS LIGHTNING. THIS STORM WILL BE NEAR... STATE HWY 294 MILE MARKER 10 AROUND 420 PM MDT. FRANNIE AND DEAVER AROUND 435 PM MDT. IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A STURDY BUILDING. IN ADDITION...THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS... FOR ADDITIONAL INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE. BRIEF HEAVY RAIN...WHICH MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND UNDERPASSES...IS ALSO LIKELY LATE THIS AFTERNOON. DO NOT DRIVE YOUR VEHICLE ON A FLOODED ROADWAY. REPORT HAZARDOUS WEATHER TO THE NATIONAL WEATHER SERVICE OFFICE IN RIVERTON AT 1-800-211-1448. LAT...LON 4501 10843 4459 10843 4452 10924 4499 10956 TIME...MOT...LOC 2213Z 238DEG 61KT 4477 10907 KPL
The Riverton/Lander radar (KRIW), 32 km away, was scanning. The volume nearest the first event began at 22:23 UTC.
1 lightning. Local standard time, as filed.
Lightning struck a haystack at approximately 1525MST on Friday, August 6. The stack, containing 400 tons of premium hay, smoldered for three days before becoming engulfed with flames around 1830MST Monday, August 9. Despite a large response by fire personnel, the entire stack was lost.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2010Every state in 2010This day in weather historyWarnings in Wyoming, August 2010
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: 241714.