Rapid snowmelt from a few day period of well above normal temperatures focused on the 11-13th of April resulted in minor to locally moderate flooding through much of the Big Sioux River Basin. Some areas north of I-90 lost between 2 to 5 inches of snow water equivalent (SWE) from the first to second week of April, but antecedent drought conditions resulted in only a percentage of this water…
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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 FSD wrote it up.
Rapid snowmelt from a few day period of well above normal temperatures focused on the 11-13th of April resulted in minor to locally moderate flooding through much of the Big Sioux River Basin. Some areas north of I-90 lost between 2 to 5 inches of snow water equivalent (SWE) from the first to second week of April, but antecedent drought conditions resulted in only a percentage of this water actually making it into the river system.
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 Apr 9, 5:20 AM CST, 5 hours 40 minutes earlier.
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</html>The national radar mosaic for the moment the first event began.
18 flood. Local standard time, as filed.
The Big Sioux River near Flandreau, SD rose above flood stage on the morning of April 9th before cresting around 0.72 feet above flood stage (1540.72 feet) on April 9th. The river then fell below flood stage later that evening of April 9th.
The Big Sioux River near Trent, SD rose above flood stage midday of April 9th before cresting around 3.12 feet above flood stage (1498.12 feet) on April 10th, which is in the Moderate category. The river then fell below flood stage on the evening of April 10th for a short period before rising back above flood stage on April 13th.
The Big Sioux River near Dell Rapids, SD rose above flood stage on the evening of April 9th before cresting around 1.33 feet above flood stage (13.33 feet) on April 10th. The river then fell below flood stage on the afternoon of April 11th before then rising back above flood stage on April 13th.
The Big Sioux River above Dell Rapids, SD rose above flood stage on the evening of April 9th before cresting around 0.62 feet above flood stage (1481.62 feet) on April 10th. The river then fell below flood stage on the evening of April 10th.
The Big Sioux River near Egan, SD briefly rose above flood stage from early morning to midday on April 10th. The river would again rise above flood stage on April 12th.
The Big Sioux River near Hawarden, IA rose above flood stage on the morning of April 10th before cresting around 2.39 feet above flood stage (22.89 feet) on April 13th. The river then fell below flood stage on the morning of April 16th.
The Big Sioux River near Canton, SD rose above flood stage on the morning of April 10th before cresting around 1.02 feet above flood stage (1236.02 feet) on April 10th. The river then fell below flood stage on the morning of April 13th.
The Big Sioux River near Bruce, SD rose above flood stage on the morning of April 10th before cresting around 2.43 feet above flood stage (10.43 feet) on April 11th, which is in the Moderate category. The river then fell below flood stage on the morning of April 26th. The river was above Minor flood stage at this location for 16 days and above Moderate flood stage for 6 days.
The Big Sioux River near Sioux Falls, SD at I-90 rose above flood stage on the evening of April 10th before cresting around 1.41 feet above flood stage (13.41 feet) on April 11th. The river then fell below flood stage on the afternoon of April 22nd.
The Big Sioux River south of Brookings, SD rose above flood stage on the evening of April 10th before cresting around 2.19 feet above flood stage (11.19 feet) on April 14th, which is in the Moderate category. The river then fell below flood stage on the evening of April 22nd. The river was above Minor flood stage at this location for 12 days and above Moderate stage for 5 days.
The Big Sioux River near Akron, IA rose above flood stage on the evening of April 10th before cresting around 1.94 feet above flood stage (17.94 feet) on April 14th. The river then fell below flood stage on the evening of April 16th.
The Big Sioux River near Brandon, SD rose above flood stage during the early morning of April 11th before cresting around 1.51 feet above flood stage (1305.51 feet) on April 11th. The river then fell below flood stage on the afternoon of April 18th.
The Big Sioux River near Brandon, SD rose above flood stage during the early morning of April 11th before cresting around 1.51 feet above flood stage (1305.51 feet) on April 11th. The river then fell below flood stage on the afternoon of April 18th.
The Big Sioux River near Estelline rose above flood stage during the early morning of April 11th before cresting around 2.34 feet above flood stage (1646.34 feet) on April 12th, which is in the Moderate category. The river then fell below flood stage in the early afternoon on April 24th. The river was above Minor flood stage at this location for 14 days and above Moderate stage for 4 days.
The Big Sioux River near Richland, SD rose above flood stage on the morning of April 12th before cresting around 1.36 feet above flood stage (1118.36 feet) on April 15th. The river then fell below flood stage on the evening of April 16th.
The Big Sioux River near Egan, SD again rose above flood stage on April 12th during the late afternoon before cresting 0.59 feet above flood stage (1517.09 feet) on April 15th. The river then fell below flood stage late afternoon of April 16th.
The Big Sioux River near Dell Rapids, SD rose back above flood stage around midday of April 13th before falling back below flood stage around midday of April 17th.
The Big Sioux River near Trent, SD rose back above flood stage during the afternoon of April 13th before falling back below flood stage during the morning of April 16th.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in South Dakota in 2023Every state in 2023This day in weather historyWarnings in South Dakota, April 2023
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: 1090750, 1091243, 1091264, 1091258, 1090759, 1091959, 1091326, 1090744, 1091278, 1090747, 1091960, 1091300, 1091306, 1090743, 1091961, 1090756, 1091269, 1091253.