####018016660#### FGUS73 KFSD 151634 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- 053-061-067-073-077-079-083-087-097-099-101-111-125-127-135-171645- Probabilistic Hydrologic Outlook National Weather Service Sioux Falls SD 1034 AM CST Thu Feb 15 2024 ...Spring Flood and Water Resource Outlook... This spring flood and water resource outlook is for the Sioux Falls Hydrologic Service Area (HSA), which covers portions of central and southeastern South Dakota, southwestern Minnesota, northwestern Iowa and far northeast Nebraska. The main river basins include the Missouri, James, Big Sioux, Vermillion, Redwood, West Fork of the Des Moines, Little Sioux, Rock, Floyd Rivers. .Flood Outlook Summary... A current lack of widespread substantial snow cover, largely thawed ground, and decreasing river ice currently points toward a below normal flood risk over the next 90 days. With this said, additional heavy precipitation events or cold outbreaks could change the flood risk going forward. Changes to the flood risk factors will continue to be monitored and updates provided in future outlooks. .Temperature and Precipitation... Long term precipitation deficits have existed across most location over the past several years. Recent precipitation over the past few months has shown values closer to or even above normal. Above normal temperatures over the past 90 days has allowed for decreasing river ice and thawing ground. Looking forward over the next two weeks, odds lean toward near or above normal temperatures with near to below normal precipitation. This should allow for good melting conditions, thus 'reseting' our snow cover to minimal values. Both medium and long range outlooks through early May have equal odds of above/below/near normal precipitation and temperatures. .Snow Cover and Liquid Water Content... Above normal temperatures eroded the vast majority of snow cover in late January and early February. Wednesday's snow event established a corridor of up to 0.5 inches of snow water equivalent (SWE), focused across areas north of I-90. Additional snow is expected late Thursday in early Friday mainly south of I-90. Regional snow water equivalents are below normal. .Soil Conditions and Frost Depth... The late autumn precipitation and an early snowmelt season have resulted in soil moisture profiles within normal ranges, slightly drier east of I-29 and wetter west of I-29. Soil temperature observations reveal most locations are thawed (south of I-90) or trending toward thawed (north of I-90) with temperatures in the upper several layers around or above freezing. .River and Lake Conditions... Entering the winter freeze-up months, river levels and streamflow for the James River and points west are generally running near to above normal with most other locations running near to slightly below. Reports also indicate area stock ponds and wetlands may have adequate room for additional storage of any runoff. .Probabilistic Outlooks... 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: 02/17/2024 - 05/17/2024 : 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 : 6 34 <5 23 <5 <5 Alton 12.0 16.0 18.0 : 6 32 <5 15 <5 7 Le Mars 20.0 21.0 24.0 : <5 16 <5 9 <5 <5 :West Branch Floyd River Struble 14.0 15.0 16.0 : <5 8 <5 5 <5 <5 :Floyd River Merrill 12.0 14.0 16.0 : <5 7 <5 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 : 37 71 20 61 10 46 Spencer 10.0 14.0 16.0 : 25 63 <5 8 <5 <5 :Ocheyedan River Spencer 8.0 9.5 10.5 : 7 35 <5 13 <5 6 :Little Sioux River Linn Grove 18.0 19.5 21.0 : <5 34 <5 11 <5 <5 Cherokee 17.0 21.0 24.0 : 8 35 <5 6 <5 <5 Correctionville 19.0 21.0 23.0 : <5 9 <5 5 <5 <5 :West Fork Ditch Hornick 20.0 22.0 26.5 : <5 6 <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 : 15 44 <5 34 <5 14 Dell Rapids 12.0 14.0 15.0 : 6 37 <5 18 <5 16 Sioux Falls I-90 12.0 15.0 17.0 : 6 40 <5 17 <5 8 :Skunk Creek Sioux Falls 12.0 15.0 17.0 : 6 40 <5 17 <5 8 :Big Sioux River Sioux Falls N Cliff 16.0 18.0 31.0 : 5 22 <5 18 <5 <5 :Split Rock Creek Corson 8.5 11.0 14.0 : <5 14 <5 10 <5 <5 :Rock River Luverne 10.0 12.0 14.0 : <5 18 <5 10 <5 <5 Rock Rapids 13.0 16.0 19.0 : <5 32 <5 18 <5 9 Rock Valley 16.0 17.0 19.0 : <5 18 <5 13 <5 <5 :Big Sioux River Hawarden 20.5 24.0 27.0 : 17 47 <5 31 <5 18 Akron 16.0 18.0 20.0 : 17 48 <5 42 <5 19 Sioux City 32.0 38.0 41.0 : <5 <5 <5 <5 <5 <5 :James River Huron 11.5 15.0 19.0 : 38 53 23 41 11 30 Forestburg 12.0 14.5 18.0 : 35 52 26 43 9 29 Mitchell 17.0 21.5 24.0 : 45 58 21 38 12 27 :Firesteel Creek Mount Vernon 8.0 13.0 15.0 : 59 36 17 21 9 17 :James River Scotland 13.0 16.0 18.0 : 32 50 24 38 15 29 Yankton 12.0 16.0 21.0 : 27 41 23 37 13 27 :West Fork Vermillion River Parker 9.0 10.0 12.0 : 5 12 <5 10 <5 <5 :East Fork Vermillion River Parker 12.0 14.0 16.5 : 23 47 17 39 <5 30 :Vermillion River Davis 11.0 13.0 15.0 : 24 55 21 41 <5 16 Wakonda 14.0 15.5 17.0 : 24 51 23 50 16 44 Vermillion 21.0 22.0 30.0 : 9 40 8 39 <5 <5 :Redwood River Marshall 14.0 15.0 16.5 : 10 12 7 8 6 7 :West Fork Des Moines River Avoca 1425.0 1426.0 1428.0 : 6 13 <5 10 <5 <5 Windom 19.0 21.0 25.0 : <5 11 <5 7 <5 <5 Jackson 12.0 12.5 14.0 : <5 8 <5 6 <5 <5 :Missouri River South Sioux City 30.0 33.0 36.0 : <5 9 <5 8 <5 6 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: 02/17/2024 - 05/17/2024 Location 95% 90% 75% 50% 25% 10% 5% -------- ------ ------ ------ ------ ------ ------ ------ :Floyd River Sheldon 5.9 6.1 6.3 6.8 8.9 10.8 12.6 Alton 6.0 6.1 6.4 6.8 8.3 9.7 13.1 Le Mars 10.1 10.5 11.5 12.5 13.8 15.3 17.6 :West Branch Floyd River Struble 4.1 4.3 5.3 6.4 7.8 9.8 12.4 :Floyd River Merrill 0.1 0.4 1.2 2.1 3.3 4.2 8.1 James 8.7 8.9 9.4 10.2 11.2 12.0 16.3 :Little Sioux River Milford 8.4 8.6 8.8 10.3 13.0 15.9 17.6 Spencer 5.6 5.9 6.7 8.2 10.0 11.6 12.7 :Ocheyedan River Spencer 3.0 3.1 3.4 4.1 5.4 7.2 8.2 :Little Sioux River Linn Grove 7.3 7.4 8.1 9.3 12.8 16.0 16.8 Cherokee 9.1 9.4 10.4 11.6 14.7 16.3 17.9 Correctionville 5.4 5.6 6.4 8.0 11.0 12.3 15.5 :West Fork Ditch Hornick 7.3 7.8 8.6 10.4 11.5 12.6 13.8 :Perry Creek Sioux City 7.4 7.4 7.5 8.1 8.4 8.7 9.6 :Big Sioux River Brookings 3.1 3.1 3.5 4.6 7.6 9.7 10.1 Dell Rapids 3.8 3.9 4.5 5.3 8.5 11.4 12.9 Sioux Falls I-90 8.3 8.3 8.3 8.4 10.0 11.6 12.7 :Skunk Creek Sioux Falls 8.3 8.3 8.3 8.4 10.0 11.6 12.7 :Big Sioux River Sioux Falls N Cliff 6.5 6.6 7.1 8.1 10.8 14.0 15.8 :Split Rock Creek Corson 2.1 2.2 2.3 3.0 4.5 7.1 7.7 :Rock River Luverne 4.3 4.3 4.6 4.9 5.9 7.5 8.2 Rock Rapids 7.5 7.5 7.8 8.4 9.9 11.7 12.3 Rock Valley 5.8 6.1 6.3 7.5 10.4 12.5 12.9 :Big Sioux River Hawarden 12.5 12.9 13.3 14.3 19.1 21.9 22.7 Akron 6.2 6.4 7.3 8.7 14.8 17.2 17.8 Sioux City 13.0 13.1 13.7 14.8 19.4 21.4 22.1 :James River Huron 9.8 9.8 9.8 10.6 13.0 19.8 22.1 Forestburg 7.9 7.9 7.9 9.0 14.7 17.6 21.4 Mitchell 12.7 12.7 13.0 15.8 20.9 24.4 25.8 :Firesteel Creek Mount Vernon 4.4 5.0 5.5 8.8 10.7 14.8 16.6 :James River Scotland 5.7 5.7 6.0 9.8 15.6 19.5 20.3 Yankton 4.4 4.4 4.7 6.0 14.0 22.8 24.8 :West Fork Vermillion River Parker 1.3 1.3 1.5 2.1 3.4 7.1 8.8 :East Fork Vermillion River Parker 5.6 5.7 6.1 6.9 9.4 14.3 15.7 :Vermillion River Davis 3.1 3.3 4.4 5.7 9.3 14.0 14.6 Wakonda 4.0 4.3 5.1 6.4 12.2 17.3 17.6 Vermillion 2.7 2.9 4.5 5.9 12.9 19.9 26.0 :Redwood River Marshall 7.5 8.2 8.8 10.0 12.0 14.1 16.7 :West Fork Des Moines River Avoca 1419.1 1419.2 1419.6 1420.0 1422.2 1424.4 1425.1 Windom 11.1 11.3 11.5 12.6 15.9 17.6 18.0 Jackson 8.0 8.1 8.4 8.8 10.0 10.8 11.0 :Missouri River South Sioux City 11.0 11.2 11.5 13.7 16.6 22.4 28.3 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: 02/17/2024 - 05/17/2024 LOCATION 95% 90% 75% 50% 25% 10% 5% -------- ------ ------ ------ ------ ------ ------ ------ :Floyd River Sheldon 4.2 4.1 4.1 4.1 4.1 4.1 4.1 Alton 5.3 5.3 5.3 5.2 5.1 5.0 5.0 Le Mars 8.5 8.4 8.4 7.8 7.5 7.4 7.3 :West Branch Floyd River Struble 3.6 3.6 3.5 3.4 3.4 3.3 3.3 :Floyd River Merrill 0.0 0.0 0.0 0.0 0.0 0.0 0.0 James 8.2 8.2 8.2 8.0 7.9 7.8 7.8 :Little Sioux River Milford 7.7 7.7 7.4 7.2 6.5 6.2 6.2 Spencer 4.8 4.8 4.4 4.1 3.7 3.5 3.5 :Ocheyedan River Spencer 2.6 2.6 2.5 2.3 2.2 2.1 2.1 :Little Sioux River Linn Grove 7.0 6.9 6.6 6.2 5.7 5.2 5.1 Cherokee 8.5 8.5 8.4 8.2 8.1 7.2 7.1 Correctionville 5.0 5.0 4.9 4.7 4.6 4.5 4.4 :West Fork Ditch Hornick 5.9 5.9 5.9 5.7 5.5 5.4 5.4 :Perry Creek Sioux City 6.9 6.8 6.6 6.3 6.1 6.0 5.8 :Big Sioux River Brookings 3.0 3.0 2.8 2.5 2.1 2.0 1.9 Dell Rapids 3.7 3.7 3.6 3.3 2.8 2.4 2.4 Sioux Falls I-90 5.5 5.3 5.1 4.7 3.9 3.4 3.3 :Skunk Creek Sioux Falls 5.5 5.3 5.1 4.7 3.9 3.4 3.3 :Big Sioux River Sioux Falls N Cliff 6.1 6.1 6.1 6.0 5.7 5.4 5.3 :Split Rock Creek Corson 2.0 2.0 2.0 1.8 1.6 1.4 1.4 :Rock River Luverne 4.2 4.2 4.2 4.2 4.2 4.2 4.2 Rock Rapids 7.0 7.0 7.0 6.6 6.3 6.3 6.3 Rock Valley 5.1 5.1 5.0 4.9 4.7 4.6 4.6 :Big Sioux River Hawarden 12.0 12.0 11.8 11.6 11.2 10.9 10.5 Akron 5.5 5.5 5.2 5.0 4.6 4.3 3.7 Sioux City 12.5 12.5 12.2 12.0 11.6 11.4 11.0 :James River Huron 9.5 9.5 9.5 9.3 9.2 9.2 9.2 Forestburg 6.8 6.3 5.6 4.9 4.7 4.5 4.5 Mitchell 12.3 12.3 11.9 11.0 10.8 10.5 10.5 :Firesteel Creek Mount Vernon 2.7 2.6 2.6 2.6 2.5 2.5 2.4 :James River Scotland 5.5 5.5 5.3 4.9 4.7 4.6 4.6 Yankton 4.2 4.2 4.2 4.0 3.8 3.6 3.6 :West Fork Vermillion River Parker 1.1 1.1 1.1 0.8 0.4 0.3 0.3 :East Fork Vermillion River Parker 5.5 5.5 5.4 5.1 4.6 4.2 3.9 :Vermillion River Davis 2.7 2.7 2.7 2.4 2.3 2.3 2.3 Wakonda 3.7 3.6 3.6 3.1 2.0 1.7 1.5 Vermillion 2.2 2.2 2.1 1.8 1.5 1.4 1.3 :Redwood River Marshall 7.1 7.0 6.9 6.8 6.7 6.6 6.6 :West Fork Des Moines River Avoca 1418.6 1418.6 1418.5 1418.5 1418.4 1418.3 1418.2 Windom 10.4 10.3 10.2 10.2 10.1 10.0 9.8 Jackson 7.5 7.5 7.4 7.3 7.3 7.2 7.1 :Missouri River South Sioux City 6.5 6.5 6.5 6.2 5.9 5.5 4.4 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 on February 29th, 2024. $$ Kalin ####018005921#### FGUS73 KFGF 151638 ESFFGF NDC005-027-071-281200- Probabilistic Hydrologic Outlook National Weather Service Grand Forks ND 1037 AM CST Thu Feb 15 2024 ...DEVILS LAKE OUTLOOK FOR FLOOD POTENTIAL... Devils and Stump Lakes Long-Range Probabilistic Outlook The National Weather Service provides long-range probabilistic hydrologic outlooks for Devils and Stump lakes between January and September. They will not be provided between October and December. Depending on the season, the high or low water probabilities may be omitted due to their applicability to the hydrologic situation. .OUTLOOK SUMMARY... Note: This outlook incorporates a daily average of 350 cfs worth of pumping operations on Devils Lake from June 1st through November 10th. The first half of the fall 2023 season (roughly September and October) brought above normal precipitation to much of the basin. However, since the beginning of November 2023, precipitation (and associated snowfall) has been well below normal. Therefore, drought conditions persist across the majority of the area: ranging from severe drought across northern portions of the basin to abnormally dry across the south. Climate outlooks indicate above normal temperatures to continue into spring. This will lead to early melting of any lingering snowpack and introduce the possibility of rain rather than snow heading into spring. Lastly, current lake levels are around 1449.1 ft. These levels are just slightly lower than what they were at this time last year. The next outlook for the Devils Lake basin will be issued on Thursday, February 29, 2024. .Chances of Devils and Stump Lakes Rising Above Given Lake Levels... The probability of exceeding a given lake level is the percentage of maximum lake level rises that are above that level for all the years that were run through the model using the precipitation and temperatures for those years during the valid period of the outlook. Interpretation Aid: There is a 50 percent chance that Devils Lake will rise above 49.9 feet during the valid period and only a 5 percent chance that it will rise above 51.0 feet. Note: The current gage zero datum of the Devils Lake at Creel Bay gage is 1401.33 feet NAVD88 or 1400.00 feet NGVD29. The gage zero datum of the Stump Lake at East Stump Lake gage is 1401.21 feet NAVD88 or 1400.00 feet NGVD29. Probabilities for Exceeding Listed Lake Levels FROM FEBRUARY 12, 2024 TO SEPTEMBER 30, 2024 LOCATION 95% 90% 75% 50% 25% 10% 05% -------- ------ ------ ------ ------ ------ ------ ------ Devils Lake..... CREEL BAY 49.6 49.6 49.7 49.9 50.2 50.6 51.0 Stump Lake..... EAST STUMP LAKE 49.6 49.6 49.7 49.9 50.2 50.6 51.0 .Current and Previous Record High Lake Levels... * The current height of Devils Lake is 1449.12 feet NGVD29. * The current height of Stump Lake is 1449.19 feet NGVD29. * The most recent USGS provisional record daily average height for Devils Lake at the Creel Bay gage: ...1454.30 feet on June 27 of 2011 * Previous records: ...1452.05 feet on June 27 of 2010 ...1450.93 feet on June 27 of 2009 ...1449.20 feet on May 9 of 2006 ...1449.18 feet on June 17 of 2004 ...1449.17 feet on August 2 of 2005 Note: All previous records are recorded in NGVD29. .OUTLOOK SCHEDULE... - Between January and May, only the high water exceedances will be provided with valid periods ending at the end of September. - Special Spring Flood and Water Management Outlooks will be issued in late February and early March. - For June and July, both high-water and low-water exceedances will be provided. - For August and September, only the low-water exceedances will be provided with valid periods ending at the end of November. - No probability of exceedance/non-exceedance information will be given from October through December, since lake freeze-up levels will be given in the fall outlooks previously issued. .ADDITIONAL INFORMATION... The long-range probabilistic outlook is based on high and low lake levels that were calculated for the valid period using multiple scenarios of temperature and precipitation from 1949 to 2018 and current conditions of the lake, snowcover (in winter), and soil moisture. By providing the complete range of lake level probabilities, the amount of risk associated with long-range planning decisions can be determined. These probabilistic outlooks are part of NOAA's National Weather Service's Advanced Hydrologic Prediction Services (AHPS). A YouTube video on "How to Interpret River Outlook Products" is at: www.youtube.com/watch?v=pSoEgvsnpv4 This outlook is also presented as probability graphs of lake height for the full period as well as weekly probabilities. The outlook graphics and explanations that help in interpreting these outlooks are available on the NWS Grand Forks AHPS web page at: water.weather.gov/ahps2/index.php?wfo=FGF Wind and wave forecasts for Devils and Stump lakes are available for a 7-day period when the lakes are sufficiently ice-free at: www.weather.gov/fgf/lake_info If you have any questions, contact the NWS at 701-772-0720. You can follow us on Facebook at www.facebook.com/NWSGrandForks and on Twitter at @NWSGrandForks. $$ weather.gov/fgf NNNN