Heavy rainfall occurred over portions of the Mullen Fire Burn Scar area leading to evidence of debris flow in the backcountry wilderness during the afternoon of the 11th.
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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 CYS wrote it up.
Heavy rainfall occurred over portions of the Mullen Fire Burn Scar area leading to evidence of debris flow in the backcountry wilderness during the afternoon of the 11th.
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 Cheyenne, WY wrote its last area forecast discussion before the first event at Aug 11, 2:03 PM MST, 3 hours 7 minutes earlier.
Area Forecast Discussion National Weather Service Cheyenne WY 303 PM MDT Thu Aug 11 2022 .SHORT TERM...(Tonight and tomorrow) Issued at 303 PM MDT Thu Aug 11 2022 Key Impact Messages: 1) Hot temperatures continue this afternoon with another warm day tomorrow. Temperatures will be in the 90s east of of the Laramie Range and the western Nebraska Panhandle. 2) An isolated thunderstorm across the high terrain, west of the Laramie Range this afternoon. Brief heavy rainfall will be possible. 3) Monsoon moisture increases Friday with the best chance for showers and thunderstorms occurring west of the Laramie Range. Heavy rainfall will be the main hazard. Weather Details: Agitated cumulus has formed across Laramie Range this afternoon, with a few thunderstorms just south into Colorado. These storms are slow moving and have the threat to put down some localized heavy rainfall. The window for convection will be limited as ridging aloft begins to build through the evening and models are showing very limited instability across the area today. Temperatures warmed nicely across the region this afternoon with most everyone climbing into the 90s with a few spots across the western Nebraska panhandle. The main focus in the short term is tracking the movement of the high pressure system we have been talking about over the past few days. Models have showed this high pressure remaining stagnant through Thursday, but will finally begin to shift to the southeast Friday morning into Friday afternoon. The track of this high pressure system will influence the location and the intensity of the monsoon push. Confidence is high that this plume will advect into Carbon County by the morning and then move east toward the Laramie Range by the afternoon. The highest confidence for PoP chances remain west of the Laramie Range Friday. Although by the evening some of this showers and thunderstorms may push into the I-25 corridor. Brief heavy downpours will be possible within the strongest thunderstorm cores that may pose a Flash Flood risk. The area of high pressure will continue to push to the southeast Friday evening opening the door for more monsoon moisture to advect into the region. .LONG TERM...(Saturday night through next Thursday) Issued at 303 PM MDT Thu Aug 11 2022 Saturday...With ridging aloft breaking down slightly and the upper high drifting slightly to the east, moisture will increase slightly with PWATs approaching one inch, and with the projected weak winds aloft, storm motions will be slow, allowing for some locally heavy rains in spots. The coverage of precipitation will increase slightly and progress further to the east across southeast Wyoming. Sunday...Temperatures will cool off a few more degrees with heights aloft decreasing and an increase in afternoon and evening shower and thunderstorm coverage. As projected PWATs increase to 1 to 1.50 inches, and steering winds remain relatively light, locally heavy rain will be possible from the stronger storms. Monday...The cooling trend continues with heights and temperatures aloft decreasing, and also with plenty of cloud cover and scattered to numerous showers and thunderstorms. Projected PWATs from 1.25 to 1.50 inches and weak steering winds will help produce more locally heavy rain from the stronger storms. Tuesday...Plenty of monsoonal moisture remains overhead and with PWATS ranging from 1.25 to 1.50 inches and weak steering flow, more locally heavy rain will be possible from the stronger storms. With plenty of moisture available, scattered to numerous showers and thunderstorms are expected again. Relatively cool temperatures due to all the cloud cover and precipitation. Wednesday/Thursday...With the flow aloft turning northwest, moisture will decrease slightly and decrease shower and thunderstorm coverage somewhat. && .AVIATION...(For the 18Z TAFS through 18Z Friday afternoon) Issued at 1137 AM MDT Thu Aug 11 2022 VFR conditions expected across area terminal through the forecast period. FEW clouds have begun developing over the higher terrain late this morning. Showers and thunderstorms are expected to develop late this afternoon along and west of the Laramie Range around KLAR and KRWL. Still think storms will stay far enough west of KCYS not to include any VCTS, but will monitor latest observations and AMD as needed. Gusts 20-25 kt will continue for most terminals through this afternoon, gradually calming down after 02z. && .FIRE WEATHER... Issued at 303 PM MDT Thu Aug 11 2022 Monsoon moisture advects into the region beginning this afternoon. Showers and thunderstorm chances increase Friday and into the weekend. Wetting rainfall is expected Friday through Monday. With the increase in moisture and the wetting rains, relative humidity values will be above 25 percent. Winds will become breezy but should remain at or below 20 mph. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && SHORT TERM...AW LONG TERM...RUBIN AVIATION...MB FIRE WEATHER...AW
Hazardous Weather Outlook National Weather Service Cheyenne WY 225 PM MDT Thu Aug 11 2022 NEZ002-003-019>021-054-055-095-096-WYZ102-107-108-117>119-122030- Dawes County-Box Butte County-Scotts Bluff County-Banner County- Morrill County-Kimball County-Cheyenne County- Northern Sioux County-Southern Sioux County-Niobrara County- East Platte County-Goshen County-South Laramie Range Foothills- Central Laramie County-East Laramie County- 225 PM MDT Thu Aug 11 2022 This hazardous weather outlook is for portions of panhandle Nebraska...east central Wyoming and southeast Wyoming. .DAY ONE...THIS AFTERNOON AND TONIGHT Hot temperatures are expected this afternoon with mostly sunny skies. Late morning and afternoon temperatures will range from the middle 90s to 105. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY Hot temperatures will likely continue into the weekend, but it should be a few degrees cooler each day heading into Saturday. Afternoon and evening thunderstorms will likely return by Friday afternoon and this upcoming weekend. Heavy rainfall will be possible across SE Wyoming Monday. .Spotter information statement... Spotter activation will not be required. WYZ101-103>106-109>116-122030- Converse County Lower Elevations-North Laramie Range- Ferris/Seminoe/Shirley Mountains-Shirley Basin- Central Laramie Range and Southwest Platte County- Central Carbon County-North Snowy Range Foothills- Southwest Carbon County-Sierra Madre Range- Upper North Platte River Basin-Snowy Range-Laramie Valley- South Laramie Range- 225 PM MDT Thu Aug 11 2022 This hazardous weather outlook is for portions of east central Wyoming...south central Wyoming and southeast Wyoming. .DAY ONE...THIS AFTERNOON AND TONIGHT Thunderstorms will develop across the mountains and slowly move northeast through late this evening. Some heavy rainfall is possible. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY Afternoon and evening thunderstorms will continue through this upcoming weekend and into next week, with a good chance of localized heavy rainfall. .Spotter information statement... Spotter activation will not be required.
The Cheyenne radar (KCYS), 124 km away, was scanning. The volume nearest the first event began at 00:11 UTC.
1 flash flood. Local standard time, as filed.
Radar estimates of up to 2 inches of rainfall fell over a severely burned area of the Mullen Fire Burn Scar west and south of Rob Roy Reservoir. Evidence of debris flow with ash at A Bar A Ranch on the Mullen Creek.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2022Every state in 2022This day in weather historyWarnings in Wyoming, August 2022
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: 1041575.