Flood Potential Outlook
Issued by NWS Sioux Falls, SD
Issued by NWS Sioux Falls, SD
053 FGUS73 KFSD 281232 ESFFSD IAC021-035-041-059-093-119-141-143-149-167-193-MNC033-063-081-083- 101-105-117-133-NEC043-051-SDC003-005-009-011-015-023-027-035-043- 053-061-067-073-077-079-083-087-097-099-101-111-125-127-135-281345- Probabilistic Hydrologic Outlook National Weather Service Sioux Falls SD 732 AM CDT Fri Jun 28 2024 In Table 1 below, the current (CS) and historical (HS) or normal probabilities of exceeding minor...moderate...and major flood stage are listed for the valid time period. CS values indicate the probability of reaching a flood category based on current conditions. HS values indicate the probability of reaching a flood category based on historical or normal conditions. When the value of CS is greater than HS...the probability of exceeding that level is higher than normal. When the value of CS is less than HS...the probability of exceeding that level is lower than normal. ...Table 1--Probabilities for minor...moderate and major flooding... Valid Period: 07/01/2024 - 09/29/2024 : Current and Historical : Chances of Exceeding : Flood Categories : as a Percentage (%) Categorical : Flood Stages (FT) : Minor Moderate Major Location Minor Mod Major : CS HS CS HS CS HS -------- ----- ----- ----- : --- --- --- --- --- --- :Floyd River Sheldon 12.0 14.0 16.0 : 22 14 20 10 8 <5 Alton 12.0 16.0 18.0 : 20 15 17 9 11 7 Le Mars 20.0 21.0 24.0 : 20 10 16 7 <5 <5 :West Branch Floyd River Struble 14.0 15.0 16.0 : 7 <5 5 <5 <5 <5 :Floyd River Merrill 12.0 14.0 16.0 : 10 5 6 <5 <5 <5 James 26.0 30.0 34.0 : <5 <5 <5 <5 <5 <5 :Little Sioux River Milford 12.0 14.0 16.0 : >98 67 >98 41 34 19 Spencer 10.0 14.0 16.0 : >98 40 16 11 <5 <5 :Ocheyedan River Spencer 8.0 9.5 10.5 : 34 18 18 13 15 6 :Little Sioux River Linn Grove 18.0 19.5 21.0 : >98 20 16 12 11 10 Cherokee 17.0 21.0 24.0 : >98 21 14 11 <5 <5 Correctionville 19.0 21.0 23.0 : >98 12 >98 9 >98 <5 :West Fork Ditch Hornick 20.0 22.0 26.5 : <5 <5 <5 <5 <5 <5 :Perry Creek Sioux City 24.0 26.0 28.0 : <5 <5 <5 <5 <5 <5 :Big Sioux River Brookings 9.0 10.5 12.0 : 34 18 20 11 8 5 Dell Rapids 12.0 14.0 15.0 : 21 16 12 10 9 <5 Sioux Falls I-90 12.0 15.0 17.0 : 22 20 10 <5 8 <5 :Skunk Creek Sioux Falls 12.0 15.0 17.0 : 22 20 10 <5 8 <5 :Big Sioux River Sioux Falls N Cliff 16.0 18.0 31.0 : 18 12 14 11 <5 <5 :Split Rock Creek Corson 8.5 11.0 14.0 : >98 24 22 5 8 <5 :Rock River Luverne 10.0 12.0 14.0 : 13 13 11 6 7 <5 Rock Rapids 13.0 16.0 19.0 : 33 18 17 12 12 6 Rock Valley 16.0 17.0 19.0 : 17 9 15 5 10 <5 :Big Sioux River Hawarden 20.5 24.0 27.0 : >98 25 >98 16 20 13 Akron 16.0 18.0 20.0 : >98 26 >98 17 >98 14 Sioux City 32.0 38.0 41.0 : 9 <5 <5 <5 <5 <5 :James River Huron 11.5 15.0 19.0 : 19 28 13 13 <5 <5 Forestburg 12.0 14.5 18.0 : 24 34 11 14 <5 <5 Mitchell 17.0 21.5 24.0 : >98 35 5 7 <5 <5 :Firesteel Creek Mount Vernon 8.0 13.0 15.0 : >98 >98 7 9 <5 <5 :James River Scotland 13.0 16.0 18.0 : >98 24 >98 12 6 5 Yankton 12.0 16.0 21.0 : >98 14 >98 8 >98 5 :West Fork Vermillion River Parker 9.0 10.0 12.0 : >98 7 <5 <5 <5 <5 :East Fork Vermillion River Parker 12.0 14.0 16.5 : 12 13 10 11 5 6 :Vermillion River Davis 11.0 13.0 15.0 : >98 18 >98 15 <5 5 Wakonda 14.0 15.5 17.0 : >98 19 >98 17 >98 16 Vermillion 21.0 22.0 30.0 : >98 15 >98 14 <5 <5 :Redwood River Marshall 14.0 15.0 16.5 : 7 6 <5 6 <5 <5 :West Fork Des Moines River Avoca 1425.0 1426.0 1428.0 : >95 8 >95 7 <5 <5 Windom 19.0 21.0 25.0 : >95 6 >95 <5 <5 <5 Jackson 12.0 12.5 14.0 : >95 <5 >95 <5 <5 <5 :Missouri River South Sioux City 30.0 33.0 36.0 : 5 10 <5 8 <5 7 Legend CS = Conditional Simulation (Current Outlook) HS = Historical Simulation FT = Feet In Table 2 below...the 95 through 5 percent columns indicate the probability of exceeding the listed stage levels (FT) for the valid time period. ...Table 2--Exceedance Probabilities... Chance of Exceeding Stages at Specific Locations Valid Period: 07/01/2024 - 09/29/2024 Location 95% 90% 75% 50% 25% 10% 5% -------- ------ ------ ------ ------ ------ ------ ------ :Floyd River Sheldon 7.0 7.0 7.0 8.1 11.0 15.8 16.3 Alton 7.0 7.0 7.0 8.1 11.5 18.4 20.0 Le Mars 12.8 12.8 12.8 15.3 18.8 21.4 22.6 :West Branch Floyd River Struble 6.0 6.0 6.0 6.8 10.6 12.2 14.9 :Floyd River Merrill 3.2 3.2 3.2 4.8 8.3 12.1 14.8 James 11.2 11.2 11.2 12.5 16.2 20.8 24.2 :Little Sioux River Milford 15.1 15.1 15.1 15.1 17.0 18.8 23.7 Spencer 12.2 12.2 12.2 12.2 12.4 15.0 15.7 :Ocheyedan River Spencer 7.8 7.8 7.8 7.8 8.6 10.9 11.7 :Little Sioux River Linn Grove 19.2 19.2 19.2 19.2 19.2 21.1 21.4 Cherokee 19.5 19.5 19.5 19.5 19.5 21.8 22.1 Correctionville 25.9 25.9 25.9 25.9 25.9 25.9 25.9 :West Fork Ditch Hornick 8.1 8.2 8.8 10.3 11.4 14.2 16.1 :Perry Creek Sioux City 7.5 7.5 7.6 8.5 9.2 10.4 12.4 :Big Sioux River Brookings 6.9 6.9 6.9 7.1 10.2 11.1 13.0 Dell Rapids 10.4 10.4 10.4 10.4 11.6 14.5 16.9 Sioux Falls I-90 11.8 11.8 11.8 11.8 11.9 14.7 18.9 :Skunk Creek Sioux Falls 11.8 11.8 11.8 11.8 11.9 14.7 18.9 :Big Sioux River Sioux Falls N Cliff 13.8 13.8 13.8 13.8 14.7 20.2 26.0 :Split Rock Creek Corson 8.8 8.8 8.8 8.8 10.6 12.8 15.6 :Rock River Luverne 5.7 5.7 5.7 7.0 8.7 12.9 14.7 Rock Rapids 11.6 11.6 11.6 11.9 14.5 21.4 25.1 Rock Valley 11.4 11.4 11.4 11.4 14.3 18.9 19.9 :Big Sioux River Hawarden 24.6 24.6 24.6 24.6 25.8 32.6 34.5 Akron 20.4 20.4 20.4 20.4 20.4 23.0 23.5 Sioux City 27.6 27.6 27.6 27.6 27.6 31.7 33.5 :James River Huron 10.1 10.1 10.1 10.3 11.1 15.6 16.2 Forestburg 9.5 9.5 9.5 9.5 11.7 14.7 15.4 Mitchell 18.3 18.3 18.3 18.3 18.3 20.3 21.8 :Firesteel Creek Mount Vernon 11.1 11.1 11.1 11.1 11.2 12.4 13.9 :James River Scotland 17.4 17.4 17.4 17.4 17.4 17.4 18.8 Yankton 21.6 21.6 21.6 21.6 21.6 21.6 23.0 :West Fork Vermillion River Parker 9.6 9.6 9.6 9.6 9.6 9.6 9.8 :East Fork Vermillion River Parker 9.4 9.4 9.4 9.4 9.4 14.1 16.7 :Vermillion River Davis 13.5 13.5 13.5 13.5 13.5 14.1 14.8 Wakonda 17.5 17.5 17.5 17.5 17.5 17.6 17.8 Vermillion 27.2 27.2 27.2 27.2 27.2 27.2 28.0 :Redwood River Marshall 11.3 11.3 11.3 11.3 11.3 13.3 14.7 :West Fork Des Moines River Avoca 1426.9 1426.9 1426.9 1426.9 1426.9 1427.2 1427.6 Windom 21.9 21.9 21.9 21.9 21.9 21.9 21.9 Jackson 13.6 13.6 13.6 13.6 13.6 13.6 13.6 :Missouri River South Sioux City 24.6 24.6 24.6 24.6 24.6 24.6 29.6 In Table 3 below...the 95 through 5 percent columns indicate the probability of falling below the listed stage levels (FT) for the valid time period. ...Table 3--Nonexceedance Probabilities... Chance of Falling Below Stages at Specific Locations Valid Period: 07/01/2024 - 09/29/2024 LOCATION 95% 90% 75% 50% 25% 10% 5% -------- ------ ------ ------ ------ ------ ------ ------ :Floyd River Sheldon 5.1 4.8 4.7 4.6 4.5 4.5 4.5 Alton 5.9 5.8 5.7 5.6 5.6 5.5 5.5 Le Mars 9.7 9.3 8.6 7.3 6.9 6.6 6.6 :West Branch Floyd River Struble 4.4 4.2 4.1 4.0 4.0 3.9 3.9 :Floyd River Merrill 0.9 0.7 0.5 0.2 0.1 0.1 0.0 James 9.2 9.1 9.0 8.8 8.7 8.7 8.6 :Little Sioux River Milford 9.7 9.1 8.7 8.4 8.1 7.9 7.9 Spencer 7.4 7.2 6.3 5.9 5.4 5.2 5.1 :Ocheyedan River Spencer 3.6 3.5 3.2 3.0 2.9 2.8 2.8 :Little Sioux River Linn Grove 9.2 8.9 8.1 7.8 7.4 7.3 7.2 Cherokee 10.4 9.5 8.9 8.7 8.6 8.4 8.4 Correctionville 7.2 7.0 6.5 6.2 6.0 5.9 5.9 :West Fork Ditch Hornick 7.4 7.3 7.1 7.0 6.9 6.9 6.9 :Perry Creek Sioux City 7.1 7.1 7.1 7.0 6.8 6.8 6.7 :Big Sioux River Brookings 4.4 3.9 3.4 3.2 2.9 2.8 2.8 Dell Rapids 5.5 5.3 4.6 4.3 3.9 3.8 3.7 Sioux Falls I-90 7.6 7.2 6.3 5.9 5.5 5.3 5.2 :Skunk Creek Sioux Falls 7.6 7.2 6.3 5.9 5.5 5.3 5.2 :Big Sioux River Sioux Falls N Cliff 8.0 7.8 7.4 6.9 6.5 6.4 6.3 :Split Rock Creek Corson 2.7 2.7 2.6 2.5 2.4 2.3 2.3 :Rock River Luverne 4.7 4.6 4.6 4.5 4.5 4.5 4.5 Rock Rapids 8.2 8.1 7.9 7.7 7.6 7.5 7.5 Rock Valley 5.9 5.5 5.2 4.9 4.8 4.7 4.7 :Big Sioux River Hawarden 14.8 14.3 13.9 13.2 13.0 12.8 12.7 Akron 9.6 8.9 8.3 7.3 7.0 6.6 6.5 Sioux City 15.3 15.0 14.3 13.8 13.7 13.3 13.3 :James River Huron 9.9 9.8 9.7 9.6 9.5 9.5 9.5 Forestburg 7.4 7.1 6.5 6.2 6.1 5.9 5.9 Mitchell 13.7 13.0 12.2 11.9 11.7 11.5 11.4 :Firesteel Creek Mount Vernon 3.1 2.9 2.7 2.6 2.6 2.6 2.6 :James River Scotland 7.5 5.9 5.3 5.1 5.0 4.9 4.9 Yankton 5.6 4.8 4.5 4.4 4.3 4.2 4.2 :West Fork Vermillion River Parker 1.4 1.2 1.1 1.0 1.0 1.0 1.0 :East Fork Vermillion River Parker 5.7 5.6 5.6 5.4 5.3 5.3 5.3 :Vermillion River Davis 3.5 3.2 3.0 2.8 2.7 2.6 2.6 Wakonda 4.6 4.4 4.2 3.9 3.8 3.8 3.8 Vermillion 2.4 2.2 1.9 1.6 1.5 1.5 1.4 :Redwood River Marshall 7.3 7.2 7.0 7.0 6.9 6.9 6.9 :West Fork Des Moines River Avoca 1419.4 1419.2 1419.2 1419.0 1419.0 1418.9 1418.9 Windom 11.7 11.4 11.2 11.0 10.8 10.8 10.8 Jackson 8.4 8.2 8.0 7.9 7.8 7.8 7.8 :Missouri River South Sioux City 12.7 11.4 10.9 10.8 10.7 10.4 10.0 These long-range probabilistic outlooks contain forecast values that are calculated using multiple season scenarios from 30 or more years of climatological data...including current conditions of the river...soil moisture...snow cover and 30 to 90 day long-range outlooks of temperature and precipitation. By providing a range of probabilities...the level of risk associated with long-range planning decisions can be determined. These probabilistic forecasts are part of the National Weather Service`s Advanced Hydrologic Prediction Service. Visit our web site weather.gov/fsd for more weather and water information. The next outlook will be issued by the end of July. $$ Kalin