Strong boundary layer winds mixed to the surface and brought high wind to the wind prone areas south and east of Casper. Maximum wind gusts included 71 mph along Hat Six Road in Evansville, Wyoming and 65 mph to the south of Casper, Wyoming along Wyoming Boulevard.
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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 RIW wrote it up.
Strong boundary layer winds mixed to the surface and brought high wind to the wind prone areas south and east of Casper. Maximum wind gusts included 71 mph along Hat Six Road in Evansville, Wyoming and 65 mph to the south of Casper, Wyoming along Wyoming Boulevard.
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 Mar 6, 4:37 AM MST, 2 hours 17 minutes earlier.
Area Forecast Discussion National Weather Service Riverton WY 437 AM MST Sat Mar 6 2021 .SHORT TERM...Today through Sunday Issued at 253 AM MST Sat Mar 6 2021 Another mild and mostly sunny day across the Cowboy State. A weak shortwave will approach the area leading to strong southwest winds this afternoon in the wind corridor from Rock Springs through southern Johnson County. Natrona county will see the highest winds with gusts into the 50 mph range, and occasional gusts near 60 mph are possible at Outer Drive. Above average temperatures and low humidities will contribute their own problem and bring elevated fire weather concerns across much of this same area. As the shortwave moves through the area this afternoon and evening snow showers will increase in the far west. Models continued to weaken this system with the 00Z runs so we kept the PoP and QPF on the low end. Most of the activity will be in the mountains and will not amount to much accumulation. Most activity will be done by midnight. Weak ridging takes hold again on Sunday leading to another mild and dry day. A deepening trough along the West Coast will keep winds breezy in the wind corridor from the Green Mountains to Casper, but not near as strong as Saturday. Elevated fire weather will be a concern again for southeast Fremont and Natrona Counties. .LONG TERM...Sunday night through Friday Issued at 253 AM MST Sat Mar 6 2021 Southwest flow will be maximized on Monday as a trough approaches the western CONUS. This will help warm high temperatures further, with highs east of the Divide in the upper 50s to mid 60s likely. Wind will increase in the Wind Corridor from Rock Springs through Casper as the surface pressure gradient gets a bit tighter. Meanwhile, rain and snow showers will be possible across the far northwest through the day Monday, with coverage expanding to the rest of the west Monday night into Tuesday as a shortwave arrives. A cold front will accompany this, sliding west to east across the area Tuesday. Rain and snow showers will continue across the west and north on Tuesday, and look to spread to the rest of the CWA Tuesday night through Wednesday as a stronger push of the trough arrives. Models are still showing an upslope component Wednesday night behind the cold front, which could result in most of the area seeing some snow. Snow amounts will depend in part on temperatures, and do not currently look too impressive anywhere. After Wednesday, models generally show a low sliding east over the desert southwest at varying speeds, with a north to northwest flow bringing continued chances for precipitation over the west Thursday and Friday. && .AVIATION...(For the 12Z TAFS through 12Z Sunday morning) Issued at 434 AM MST Sat Mar 6 2021 Expect VFR conditions throughout the period. A departing ridge continues to propagate to the east for Saturday with southwesterly flow. Staring around 21Z, some snow showers may be around in the vicinity of KJAC and then around 00Z at KPNA, but otherwise dry conditions are anticipated throughout the timeframe. The usual locations from KRKS to KCPR may see winds gust from late morning into early evening, but these would be well below advisory levels.&& .FIRE WEATHER... Issued AT 253 AM MST Sat Mar 6 2021 Saturday will be a breezy to windy day across much of the region, especially during the afternoon. Temperatures will be 15 to 20 degrees above normal with RHs in the upper teens to mid 20s. The greatest elevated fire threat will be across eastern Sweetwater, southeast Fremont, and Natrona counties during the afternoon. Even though fuels are not yet critical, we feel the strength of the winds warrants an issuance of a Rangeland Fire Danger Statement for this afternoon. Precipitation chances will increase this afternoon and evening across the northwest and western mountains. Snow/rain amounts look to be minimal with the weak disturbance. The next more significant chances of precipitation will be Tuesday and Wednesday across the region. && .RIW WATCHES/WARNINGS/ADVISORIES... NONE. && SHORT TERM...Hulme LONG TERM...Myers AVIATION...Clayton FIRE WEATHER...Hulme
Hazardous Weather Outlook National Weather Service Riverton WY 429 AM MST Sat Mar 6 2021 WYZ001>020-022>030-071130- 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- 429 AM MST Sat Mar 6 2021 This Hazardous Weather Outlook is for Western and Central Wyoming. .DAY ONE...Today and Tonight. Strong southwest winds expected this afternoon from Rock Springs to southern Johnson County. Elevated fire weather is also expected in this area due to lower humidities and above average temperatures. A Rangeland Fire Danger Statement is in effect for Natrona and southern Johnson Counties this afternoon. Some light snow is expected in the western mountains late this afternoon and tonight. .DAYS TWO THROUGH SEVEN...Sunday through Friday. Sunday and Monday...Elevated fire weather in central Wyoming due to gusty winds and low humidity in the afternoon. Tuesday and Wednesday...More widespread snowfall returns to much of western and central Wyoming. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed today.
Special Weather Statement National Weather Service Riverton WY 350 AM MST Sat Mar 6 2021 WYZ011-019-020-022-030-070100- Southeast Johnson County-Green Mountains and Rattlesnake Range- Natrona County Lower Elevations-Casper Mountain- East Sweetwater County- Including the cities of Kaycee, Jeffrey City, Casper, and Wamsutter 350 AM MST Sat Mar 6 2021 ...Strong Winds Likely Today... This is a special weather statement from the National Weather Service Office in Riverton. * WHAT...Southwest winds 25 to 35 mph with gusts to around 50 mph. Locally stronger gusts are possible along Outer Drive south of Casper. * WHERE...Eastern Sweetwater, southeastern Fremont, and Natrona Counties. * WHEN...10 AM MST through 6 PM MST. * IMPACTS...Mainly to transportation. Enhanced blow over risk for light and high profile vehicles, including campers and tractor trailers. Please keep two hands on your steering wheel in case of a sudden, strong wind gust.
The national radar mosaic for the moment the first event began.
1 high wind. Local standard time, as filed.
Maximum wind gusts of 71 mph were recorded along Hat Six Road and 65 mph along Wyoming Boulevard in Casper, Wyoming.
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, March 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: 940920.