A shortwave moved across Wyoming and brought some high winds to some areas. Some of the more notable gusts included 60 mph at Rock Springs, 58 mph at Buffalo and 59 mph in Lander.
Every event with a place to put it; 3 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 RIW wrote it up.
A shortwave moved across Wyoming and brought some high winds to some areas. Some of the more notable gusts included 60 mph at Rock Springs, 58 mph at Buffalo and 59 mph in Lander.
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 Jun 13, 2:01 AM MST, 7 hours 22 minutes earlier.
Area Forecast Discussion National Weather Service Riverton WY 301 AM MDT Sat Jun 13 2020 .SHORT TERM...Today through Monday night We have two concerns for today. The first to quote one of the characters from the 90s cartoon Beavis and Butthead is "Fire! Fire! Fire!". Much of the area will have elevated fire weather conditions this afternoon with the combination of hot temperatures, humidity falling into the lower teens and windy conditions. At this point, 700 millibar winds look to be around 40 to 45 knots, not quite enough for widespread high wind. In addition, fire weather looks to be more of a concern than some borderline high wind gusts. However, it could be enough to blow around things like trash cans, toupees, wigs and small, and furry animals. The second concern is thunderstorms. The atmosphere does not have a lot of moisture to work with, so coverage will be sparse. However, there will be the threat of rather strong wind gusts with any shower or storm. Temperature / dew point depressions are approaching 60 degrees in some areas, especially east of the Divide. This, combined with the strong mid level winds, could bring some very strong wind gusts with any thunderstorm that forms. This could likely be a day with a few of those dreaded "Little Green Blobs", innocent looking showers that produce only virga, but also strong wind gusts. The main threat for this would be in Johnson and Natrona counties, where a few models show a surge of mid level moisture. This may be the hottest day so far this year for some areas. Some of the hottest spots could approach 100. One fly in the ointment may be some haze or smoke that could move in, from fires from the south and keep temperatures a bit cooler. The thunderstorms should end this evening, but there could even be a few showers late tonight along the lee of the Winds and Absarokas, so we added some slight POPs. A cold front will then slowly move across the state on Sunday. The models have come into decent agreement in keeping the best forcing and moisture to the north of the area. Continuity had showers mainly across northern Wyoming and this still looks to be the case. We made only minor tweaks at this point, with trimming the southern edge of the precipitation back a bit, especially east of the Divide. The front also looks a bit slower, so we raised temperatures just a bit. The cooler temperatures should ease fire concerns somewhat, but fire statements may still be needed in some locations since winds will remain quite strong in some areas. These showers and storms should end by midnight, with mainly dry weather after midnight. Short wave ridging then moves over the area for Monday and should bring dry conditions with near normal temperatures and somewhat less wind, although it will remain breezy. The next system will begin to approach the northwest Monday night. At this point, given the fast bias of Pacific systems by the American models, we have gone with the European which keeps the evening dry and doesn't move showers into the northwest until after midnight. .LONG TERM...Tuesday through Friday A broad trough will remain over the PACNW/Northern Rockies Tuesday. This trough will keep southwest flow continuing over the forecast area through Wednesday. Breezy to windy conditions will also continue, mainly over the Wind Corridor, with cool temperatures over the northwest half of the state. More seasonal to above normal temperatures will return over areas east of the Divide, including Sweetwater County. A cold front, associated with the broad trough/upper low, will move through the area Wednesday. The coldest air from this system will most likely impact northwest portions by Wednesday morning, but could infiltrate through western and northern portions. There will be a chance for snow Tuesday night, with drier air quickly moving in over the far west by mid to late morning Wednesday. Strong winds will be possible ahead of the front, but the timing of the front remains Wednesday, with gusty winds continuing in flux. Cyclonic flow/general troughiness will continue over the region Thursday and Friday, which will temperatures normal to slightly below normal. Overall, conditions will be mainly dry and seasonal next week. The best chance for precipitation will be over northwest portions Tuesday into Wednesday morning. && .AVIATION...For the 12Z TAFS through 12Z Sunday VFR conditions will occur through the period. Windy conditions will occur at most sites today with the wind decreasing after 01Z. Isolated showers and storms will be possible near KCPR around 00Z through 03Z. Isolated showers will be possible in the western mountains after 03Z through 12Z Sunday. && .FIRE WEATHER... ...Elevated fire weather likely this afternoon... A combination of low humidity, windy conditions and hot temperatures will bring elevated fire weather to much of the area this afternoon. A slow moving weather system may bring isolated showers and thunderstorms to northwestern Wyoming and portions of Johnson County this afternoon and evening. Otherwise, expect dry conditions today. Mixing and smoke dispersal will generally be very good to excellent. Fire conditions should improve somewhat on Sunday, with somewhat cooler temperatures and somewhat higher humidity, especially in western Wyoming. && .RIW WATCHES/WARNINGS/ADVISORIES... NONE. && SHORT TERM...Hattings LONG TERM...LaVoie AVIATION...Ross FIRE WEATHER...Hattings
Hazardous Weather Outlook National Weather Service Riverton WY 310 AM MDT Sat Jun 13 2020 WYZ001>020-022>030-141100- 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- 310 AM MDT Sat Jun 13 2020 This Hazardous Weather Outlook is for Western and Central Wyoming. .DAY ONE...Today and tonight. Elevated fire weather conditions across southwest and central Wyoming. Windy conditions across much of central and southern Wyoming. Isolated thunderstorms in far western and eastern portions of the area. .DAYS TWO THROUGH SEVEN...Sunday through Friday. Sunday...Isolated thunderstorms in northern Wyoming. Windy conditions continue in central and southern Wyoming. Monday...Elevated fire conditions across all, but far western portions. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions, according to standard operating procedures.
Special Weather Statement National Weather Service Riverton WY 917 AM MDT Sat Jun 13 2020 WYZ002>011-014>020-022-025-026-028>030-140100- 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-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- Upper Green River Basin Foothills-Upper Green River Basin- Rock Springs and Green River-Flaming Gorge-East Sweetwater County- Including the cities of Clark, Cody, Meeteetse, Basin, Greybull, Lovell, Powell, Shell, Thermopolis, Ten Sleep, Worland, Buffalo, Kaycee, Dubois, Riverton, Shoshoni, Lander, Jeffrey City, Casper, Pinedale, La Barge, Big Piney, Farson, Rock Springs, Green River, and Wamsutter 917 AM MDT Sat Jun 13 2020 This is a special weather statement from the National Weather Service Office in Riverton. * WHAT...South to southwest wind between 25 and 35 mph with gusts between 45 and 55 mph. Localized gusts to 60 mph could occur. * WHERE...Western and central Wyoming. * WHEN...Now through 7 PM. * IMPACTS...Mainly to transportation especially on west to east orientated roads. There could be control issues especially for light and high profile vehicles, including campers and tractor trailers. * ADDITIONAL DETAILS...Please keep two hands on your steering wheel in case of a sudden, strong wind gust. 21
The national radar mosaic for the moment the first event began.
3 high wind. Local standard time, as filed.
A 59 mph wind gust was recorded at the Lander, Wyoming airport.
A wind gust of 58 mph was recorded at the Johnson County airport.
A 60 mph wind gust was recorded at the Sweetwater County airport.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2020Every state in 2020This day in weather historyWarnings in Wyoming, June 2020
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: 899213, 899210, 899215.