Repeated thunderstorm development on an east-west boundary across the Sioux Falls metro area produced a localized 3 to 6 inches of rainfall in a few hours. Flooding impacts were mainly felt in areas of rapid urban runoff, with other surrounding less-urbanized areas in severe to extreme drought able to avoid any flooding.
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 FSD wrote it up.
Repeated thunderstorm development on an east-west boundary across the Sioux Falls metro area produced a localized 3 to 6 inches of rainfall in a few hours. Flooding impacts were mainly felt in areas of rapid urban runoff, with other surrounding less-urbanized areas in severe to extreme drought able to avoid any flooding. A 24-hour rainfall record of 5.67 inches was established at the Sioux Falls 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 Sioux Falls, SD wrote its last area forecast discussion before the first event at Aug 6, 9:50 PM CST, 4 hours 23 minutes earlier.
AREA FORECAST DISCUSSION National Weather Service Sioux Falls SD 1050 PM CDT Sat Aug 6 2022 .SHORT TERM...(This Evening through Sunday) Issued at 249 PM CDT Sat Aug 6 2022 The threat for isolated stronger updrafts and heavy rain continue to be the main concerns tonight into Sunday. With freezing levels still forecast to be about 14000 feet AGL and deep moisture through the column the PWAT values are up around 2 inches. As an upper level wave will move across the Dakotas tonight into Sunday which will back the low and mid level flow, focusing lift across much of the area. Where exactly development will take place is not an easy call, but somewhere near I-90 later tonight into Sunday morning when the backed flow maximizes across the area. Confidence is fairly high that the low to mid level flow will allow for development later tonight into Sunday morning as the surface instability to the south does not look like it will allow for rapid development which would perturb the mid level flow into southeast SD and southwest MN. So, with all of that being said, believe we will see scattered activity through late evening, maybe a few stronger updrafts in northwest IA, then a broader area of showers and thunderstorms overnight into Sunday morning. Some locations will likely see 1 to 3 inches of rainfall but again just where that will be is the big question. Parts of northwest IA and southwest MN seem to have the better chances but also parts of east central SD. The right entrance region of the upper level jet swings through Sunday which will bring a gradual end of showery activity from northwest to southeast through the day into Sunday night. Still some threat for higher rainfall amounts but forcing will weaken through the day. Northwest IA appears to have the better chance for some higher amounts. Severe weather looks to be a minimal threat. Temperatures on Sunday in most locations will be on the cooler side with highs in the lower to mid 70s. Some warmer and humid readings will linger in northwest IA closer to the surface front. .LONG TERM...(Sunday Night through Saturday) Issued at 249 PM CDT Sat Aug 6 2022 Cooler and drier air will filter in on Sunday night and bring an end to the precipitation from northwest to southeast. With this cooler and drier air temperatures will fall into the 50s by Monday morning. Monday should prove to be a very nice day with dew points in the 50s, lighter winds, abundant sunshine and highs mostly in the 70s. Upper level ridging will try to build across the area through the week, with a strong ridge building to the west of the area. This should bring mostly dry conditions and above normal temperatures, although not excessively so. Mostly highs in the 80s to lower 90s and lows in the 60s. Friday and Saturday may see more widespread highs in the 90s if the ridge can build east enough. More than likely there will be a couple of periods of shower and thunderstorm potential with weak waves in the upper level flow but timing and location confidence pretty low. && .AVIATION...(For the 06Z TAFS through 06Z Sunday night) Issued at 1049 PM CDT Sat Aug 6 2022 Aside from a few showers across NE Nebraska, latest radar imagery shows quiet conditions across the region. Should see this relative lull in precipitation continue for a few more hours, before showers begin to blossom again prior to daybreak. Similar to today, should see coverage remain scattered in nature, with perhaps a few thunderstorms possible during the afternoon hours. However, given that confidence remains low concerning development and timing, have opted to exclude any mention of thunder for this TAF issuance. Will continue to monitor trends and amend if necessary. Otherwise, the main concern throughout the period will be lowing cigs - as MVFR and even IFR levels become more widespread after daybreak, especially along and south of I-90. Should see cigs slowly improve toward the end of the period, as rain gradually diminishes from west to east. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && SHORT TERM...08 LONG TERM...08 AVIATION...SST
Hazardous Weather Outlook National Weather Service Sioux Falls SD 920 PM CDT Sat Aug 6 2022 IAZ001>003-012>014-020>022-031-032-MNZ071-072-080-081-089-090-097- 098-NEZ013-014-SDZ038>040-050-052>071-080230- Lyon-Osceola-Dickinson-Sioux-O'Brien-Clay-Plymouth-Cherokee- Buena Vista-Woodbury-Ida-Lincoln-Murray-Cottonwood-Nobles-Jackson- Pipestone-Rock-Dixon-Dakota-Beadle-Kingsbury-Brookings-Gregory- Jerauld-Sanborn-Miner-Lake-Moody-Brule-Aurora-Davison-Hanson-McCook- Minnehaha-Charles Mix-Douglas-Hutchinson-Turner-Bon Homme-Yankton- Union- 920 PM CDT Sat Aug 6 2022 This Hazardous Weather Outlook is for northwest Iowa, west central Iowa, southwest Minnesota, northeast Nebraska, central South Dakota, east central South Dakota, south central South Dakota and southeast South Dakota. .DAY ONE...Tonight. Periods of rain and embedded thunderstorms are expected through tonight. While the risk of severe storms is low, stronger storms will bring a potential for heavy rainfall rates. This could cause localized ponding of water, especially in urban areas. .DAYS TWO THROUGH SEVEN...Sunday through Friday. Scattered showers and storms will continue into Sunday night. However, the risk of severe weather or additional heavy rain is low. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
The Sioux Falls radar (KFSD), 3 km away, was scanning. The volume nearest the first event began at 08:15 UTC.
3 flash flood. Local standard time, as filed.
Multiple vehicles were stranded in high water in the streets of northern and western Sioux Falls.
Street flooding was ongoing at 6th and Cliff Ave.
Significant street flooding was present at Interstate 229 and 10th Street.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in South Dakota in 2022Every state in 2022This day in weather historyWarnings in South Dakota, 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: 1054547, 1054548, 1054550.