A high-based thunderstorm produced a maximum wind gust of 61 mph at Central Wyoming Regional 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.
A high-based thunderstorm produced a maximum wind gust of 61 mph at Central Wyoming Regional 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 5, 4:20 PM MST, 0 minutes earlier.
Area Forecast Discussion National Weather Service Riverton WY 520 PM MDT Mon Jul 5 2021 .SHORT TERM...(This evening through Tuesday night) Issued at 217 PM MDT Mon Jul 5 2021 Scattered showers and thunderstorms are ongoing again this afternoon as a shortwave moves east across the CWA. The first round of showers that pushed into western Wyoming early this morning is now on its way out of eastern areas. With ample clearing behind this first round, convection should continuing increasing in coverage from west to east. The best chance for a stronger storm or two should be across central and eastern portions of the area where slightly increased instability and shear could allow for more organized updrafts. The main concern will be gusty winds and a low hail threat; with PWAT values above normal brief heavy rain is the most likely scenario. This activity will end from west to east this evening with storms pushing out of eastern areas by around midnight. On Tuesday ridging builds back in, which will mark the return of warmer and drier conditions. There could be a few showers across higher elevations during the afternoon, but most areas will be dry with highs warming to near or a few degrees above normal. .LONG TERM...(Wednesday through Monday) Issued at 217 PM MDT Mon Jul 5 2021 Wednesday and Thursday will be very warm to hot. Light wind on Wednesday. Thursday will see breezy areas in the west, south, and central. Low relative humidity in the breezy areas will elevate fire weather concerns in these locations. Very isolated showers or storms may occur in the far north Wed and Thurs afternoon and evening. A cold front and weather disturbance will push into northern WY late Thursday night and Friday. The cold front will push south and bank up against the east slopes of the divide during the day Friday. Any shower and storm activity looks to be over the northeast zones only and not into central zones. The west will be dry Friday and a little cooler. Saturday will be dry and warmer. Sunday will be very warm to hot again with dry weather expected. Next Monday looks dry for most of the region and very warm to hot. Isolated afternoon showers or storms are possible over and near the mountains. High temperatures, Wednesday and Thursday will be in the 80s to around 90 west of the divide, and 90s east of the divide. A few places may reach 100 degrees in the Big Horn basin both days. Friday will be around 10 degrees cooler east of the divide, and around 5 degrees of cooling in the west. Saturday will be warmer. Sunday and Monday will see highs once again in the 90s east of the divide, and 85 to 90 in the west. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday) Issued at 515 PM MDT Mon Jul 5 2021 VFR conditions are to occur at the terminal sites. Evening showers and storms will occur with most of the activity ending around 03Z. Isolated showers and storms may linger through 06Z from KBYG to KCPR. Some storms will have brief heavy rain, producing local MVFR conditions. Wind gusts around 30 knots will occur with storms. Partial mountain obscuration will occur at times. Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for the latest information on icing and turbulence forecasts. && .FIRE WEATHER... Issued AT 217 PM MDT Mon Jul 5 2021 Scattered showers and thunderstorms are ongoing as a shortwave moves across the area. This activity will continue through this evening, ending from west to east around midnight. Gusty and erratic outflow winds are the main concern with these storms, as well as an isolated dry lightning threat across southern zones. A warming and drying trend will being on Tuesday as high pressure builds into the area, with little precipitation expected through the week. && .RIW WATCHES/WARNINGS/ADVISORIES...None && SHORT TERM...Myers LONG TERM...AR AVIATION...AR FIRE WEATHER...Myers
Hazardous Weather Outlook National Weather Service Riverton WY 449 AM MDT Mon Jul 5 2021 WYZ001>020-022>030-061100- 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- 449 AM MDT Mon Jul 5 2021 This Hazardous Weather Outlook is for Western and Central Wyoming. .DAY ONE...Today and Tonight. Scattered to numerous showers and thunderstorms are expected this afternoon and evening, especially across northwest Wyoming. Brief gusty winds are possible near any showers. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday. No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed.
Special Weather Statement National Weather Service Riverton WY 204 PM MDT Mon Jul 5 2021 WYZ012-013-024-052030- Jackson Hole-Teton and Gros Ventre Mountains-Salt River and Wyoming Ranges- 204 PM MDT Mon Jul 5 2021 ...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN LINCOLN AND SOUTH CENTRAL TETON COUNTIES UNTIL 230 PM MDT... At 203 PM MDT, Doppler radar was tracking a strong thunderstorm near Hoback, or 13 miles northeast of Alpine, moving east at 20 mph. Pea size hail and winds in excess of 40 mph will be possible with this storm. This strong thunderstorm will be near... Hoback around 220 PM MDT. Other locations impacted by this storm include Hoback Campground. PRECAUTIONARY/PREPAREDNESS ACTIONS... Brief heavy rainfall is also occurring with this storm. Persons in campgrounds should consider seeking sturdy shelter until this storm passes. && LAT...LON 4321 11087 4337 11087 4340 11055 4313 11058 TIME...MOT...LOC 2003Z 274DEG 15KT 4328 11082 Vorst
Special Weather Statement National Weather Service Riverton WY 215 PM MDT Mon Jul 5 2021 WYZ012-013-052030- Jackson Hole-Teton and Gros Ventre Mountains- 215 PM MDT Mon Jul 5 2021 ...SIGNIFICANT WEATHER ADVISORY FOR EAST CENTRAL TETON COUNTY UNTIL 230 PM MDT... At 215 PM MDT, Doppler radar was tracking a strong thunderstorm over Moran Junction, moving east at 25 mph. Pea size hail and winds in excess of 40 mph will be possible with this storm. This strong thunderstorm will be near... Buffalo Valley Ranch around 225 PM MDT. Other locations impacted by this storm include Hatchet Campground, Togwotee Mountain Lodge and Buffalo Ranger Station. PRECAUTIONARY/PREPAREDNESS ACTIONS... Brief heavy rainfall is also occurring with this storm. Persons in campgrounds should consider seeking sturdy shelter until this storm passes. && LAT...LON 4375 11050 4386 11057 4404 11027 4380 11014 TIME...MOT...LOC 2015Z 248DEG 23KT 4382 11048 Vorst
Special Weather Statement National Weather Service Riverton WY 326 PM MDT Mon Jul 5 2021 WYZ023-024-052145- Star Valley-Salt River and Wyoming Ranges- 326 PM MDT Mon Jul 5 2021 ...SIGNIFICANT WEATHER ADVISORY FOR WEST CENTRAL LINCOLN COUNTY UNTIL 345 PM MDT... At 326 PM MDT, Doppler radar was tracking a strong thunderstorm over Afton, moving east at 25 mph. Pea size hail and winds in excess of 40 mph will be possible with this storm. This strong thunderstorm will be near... Corral Creek Guard Station around 345 PM MDT. Other locations impacted by this storm include Fairview, Afton Municipal Airport and Lincoln County Fairgrounds. PRECAUTIONARY/PREPAREDNESS ACTIONS... Brief heavy rainfall is also occurring with this storm. Persons in campgrounds should consider seeking sturdy shelter until this storm passes. && LAT...LON 4263 11097 4276 11102 4290 11067 4267 11058 TIME...MOT...LOC 2126Z 251DEG 20KT 4270 11091 Vorst
Special Weather Statement National Weather Service Riverton WY 458 PM MDT Mon Jul 5 2021 WYZ015-017-018-052330- Wind River Basin-Wind River Mountains East-Lander Foothills- 458 PM MDT Mon Jul 5 2021 ...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL FREMONT COUNTY UNTIL 530 PM MDT... At 456 PM MDT, Doppler radar was tracking strong thunderstorms along a line extending from near Diversion Dam Rest Area to near Fiddlers Lake. Movement was northeast at 15 mph. Pea size hail and winds in excess of 40 mph will be possible with these storms. Strong thunderstorms will be near... Pilot Butte Reservoir around 525 PM MDT. Lander around 530 PM MDT. Other locations impacted by these storms include Lander Hunt Field and Sinks Canyon Campground. PRECAUTIONARY/PREPAREDNESS ACTIONS... Brief heavy rainfall is also occurring with this storm. Persons in campgrounds should consider seeking sturdy shelter until these storms pass. && LAT...LON 4331 10868 4271 10849 4264 10880 4321 10901 TIME...MOT...LOC 2256Z 213DEG 12KT 4319 10898 4266 10881 Vorst
Special Weather Statement National Weather Service Riverton WY 514 PM MDT Mon Jul 5 2021 WYZ007-017>019-052345- Owl Creek and Bridger Mountains-Wind River Basin-Green Mountains and Rattlesnake Range-Lander Foothills- 514 PM MDT Mon Jul 5 2021 ...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN HOT SPRINGS AND CENTRAL FREMONT COUNTIES UNTIL 545 PM MDT... At 514 PM MDT, Doppler radar was tracking strong thunderstorms along a line extending from near Pilot Butte Reservoir to near Red Canyon. Movement was northeast at 50 mph. Pea size hail and wind gusts of 50 to 55 mph will be possible with these storms. Strong thunderstorms will be near... Pavillion around 520 PM MDT. Sand Draw around 540 PM MDT. Other locations impacted by these storms include Arapahoe Elementary School, Midvale, St Stephens, Riverton Landfill, Fremont County Fairgrounds and Riverton Regional Airport. PRECAUTIONARY/PREPAREDNESS ACTIONS... Brief heavy rainfall is also occurring with this storm. If on or near Ocean Lake, get out of the water and move indoors or inside a vehicle. Remember, lightning can strike out to 10 miles from the parent thunderstorm. If you can hear thunder, you are close enough to be struck by lightning. Move to safe shelter now! Do not be caught on the water in a thunderstorm. Persons in campgrounds should consider seeking sturdy shelter until these storms pass. && LAT...LON 4353 10820 4276 10792 4264 10865 4327 10885 TIME...MOT...LOC 2314Z 244DEG 42KT 4326 10883 4269 10861 Vorst
The Riverton/Lander radar (KRIW), 2 km away, was scanning. The volume nearest the first event began at 23:19 UTC.
1 thunderstorm wind. Local standard time, as filed.
A 61 mph wind gust was reported by ASOS at Central Wyoming Regional Airport near Riverton.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2021Every state in 2021This day in weather historyWarnings in Wyoming, July 2021
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: 971097.