Relentless rainfall during July 2019 brought basin averages from 6 to 10 inches north of Interstate 90 and 4 to 6 inches south of Interstate 90. As a result, flooding along the Big Sioux River either continued, or was renewed, during the month.
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.
Relentless rainfall during July 2019 brought basin averages from 6 to 10 inches north of Interstate 90 and 4 to 6 inches south of Interstate 90. As a result, flooding along the Big Sioux River either continued, or was renewed, during the month.
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 Jul 9, 5:39 AM CST, 2 hours 21 minutes earlier.
AREA FORECAST DISCUSSION National Weather Service Sioux Falls SD 639 AM CDT Tue Jul 9 2019 .SHORT TERM...(Today and Tonight) Issued at 356 AM CDT Tue Jul 9 2019 Another humid and muggy day expected, with showers and thunderstorms mainly impacting the area during the morning hours. Ongoing swath of showers and thunderstorms will continue to stream northeast through late morning. Surface low pressure deepens over southern North Dakota this morning, with the showers and thunderstorms slowly exiting to the east ahead of the slow moving cold front. While MUCAPE values remain around 1000 j/kg, shear is weak and expected to limit the threat for severe weather with this complex. A few stronger storms could briefly contain small hail and gusts to 40 mph. Expect a break in the showers and storms midday, however destabilization this afternoon will likely lead to additional scattered shower and thunderstorm development east of I-90 in the early afternoon, and mainly across southwest Minnesota in the late afternoon. CAPE could manage to reach 1500 j/kg again, with shear increasing in the afternoon to around 30 kt. An isolated strong to severe storm will again be possible with hail up to half dollars and gusts to 60 mph before the wave exits the area this evening. The remainder of tonight will be mostly clear, with breezy west to northwest winds arriving behind the exiting low. The return of a drier airmass will drop dewpoints from the upper 60s and lower 70s into the upper 50s overnight. Lows will be in the low to mid 60s. .LONG TERM...(Wednesday through Monday) Issued at 356 AM CDT Tue Jul 9 2019 Breezy winds turn northwest on Wednesday, gusting to 35 or 40 mph during the afternoon. Skies remain mostly sunny, but cooler temperatures and dewpoints will feel more comfortable. Highs will be in the mid 70s to near 80. Upper level ridging quickly rebounds over the High Plains on Thursday and Friday, with southerly winds tapping into warmer and more humid weather. Warming trend leads to highs in the upper 80s to mid 90s, with dewpoints into the upper 60s. Expect heat index values in the 90s, and near the century mark for some areas. A wave riding the ridge may bring a chance of storms Thursday night, however the ECMWF and NAM remain dry during this time, instead focusing on Friday night instead. Ridge flattens to more of a quasi-zonal pattern this weekend, but models become even more inconsistent in the timing and track of any waves. The heat also continues this weekend into the early portion of next week. && .AVIATION...(For the 12Z TAFS through 12Z Wednesday morning) Issued at 633 AM CDT Tue Jul 9 2019 Band of rainfall with embedded thunderstorms will continue to slowly lift northeast through the forecast area today. MVFR ceilings and visibility will briefly accompany the rainfall, but should improve this afternoon as the rain exits the area. Isolated to scattered storms will be possible again in the afternoon, mainly east of I-29 and in south central SD near the Missouri River. A front sags across the region today, shifting winds to the west or west-northwest and will gust to 20 or 25 kt at times. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && SHORT TERM... LONG TERM... AVIATION...
Hazardous Weather Outlook National Weather Service Sioux Falls SD 441 AM CDT Tue Jul 9 2019 IAZ001>003-012>014-020>022-031-032-MNZ071-072-080-081-089-090-097- 098-NEZ013-014-SDZ038>040-050-052>071-100945- 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- 441 AM CDT Tue Jul 9 2019 This Hazardous Weather Outlook is for portions of 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...Today and Tonight A few strong to marginally severe storms will be possible mid afternoon into the early evening, mainly east of I-29. Hail to half dollar size and gusts up to 60 mph will be possible. .DAYS TWO THROUGH SEVEN...Wednesday through Monday No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
The national radar mosaic for the moment the first event began.
12 flood. Local standard time, as filed.
The Big Sioux River at Sioux Falls I-90 (gage site SFLS2) crested at 2.57 feet above flood stage on July 17. Significant amounts of agricultural land were flooded north of Sioux Falls. The river remained in minor flood stage at the end of the month.
The Big Sioux River near Brandon (gage site BBSS2) crested 3.18 feet above flood stage on July 17. Signficant amounts of crop and pasture land were flooded.
The Big Sioux River near Brandon (gage site BBSS2) crested 3.18 feet above flood stage on July 17. Signficant amounts of crop and pasture land were flooded.
Sixmile Creek above Brookings (gage site SMCS2) crested 1.91 feet above flood stage on July 10, flooding a few city roads on the northwest side of Brookings, as well as rural roads and agricultural land north of the city.
The Big Sioux River above Canton (gage site CBSS2) crested 0.38 feet above flood stage on July 10. Flooding impact was limited to inundation of crop and pasture land.
The Big Sioux River at Fairview (gage site FVWS2) crested 0.17 feet above flood stage on July 10, causing flooding of crop and pasture land.
North Deer Creek above Brookings (gage site NDCS2) crested 0.12 feet above flood stage on July 10, resulting in brief, but significant, flooding of agricultural lands near the creek.
The Big Sioux River below Dell Rapids (gage site DERS2) crested 1.38 feet above flood stage on July 16, flooding significant amounts of agricultural land.
The Big Sioux River near Egan (gage site EGAS2) crested 2.33 feet above flood stage on July 15, with significant flooding of agricultural land.
The Big Sioux River above Flandreau (gage site BSFS2) crested 0.86 feet above flood stage on July 14, allowing water to inundate some of the Flandreau City Park as well as agricultural lands along the river.
The Big Sioux River at Trent (gage site TRES2) crested 1.83 feet above flood stage on July 16, flooding a significant amount of agricultural land and a few county roads near the gage.
The Big Sioux River above Dell Rapids (gage site DBRS2) crested 1.16 feet above flood stage on July 16, resulting in significant flooding of agricultural land upstream of Dell Rapids, and inundating sections of the city park along the river.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in South Dakota in 2019Every state in 2019This day in weather historyWarnings in South Dakota, July 2019
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 2026-10-01. Each event’s entry at NCEI: 842560, 842749, 842750, 842553, 842755, 842768, 842554, 842559, 842556, 842555, 842557, 842558.