FGUS73 KARX 141606 ESFARX IAC005-037-043-065-067-089-131-191-MNC039-045-055-099-109-157-169- WIC001-011-019-023-043-053-057-063-081-103-119-121-123-312359- Probabilistic Hydrologic Outlook National Weather Service La Crosse WI 1050 AM CDT Thu Mar 14 2024 ...THIRD AND FINAL 2024 SPRING FLOOD AND WATER RESOURCES OUTLOOK... The overall risk for flooding this spring is below normal along the mainstem of the Mississippi River and its associated tributaries across southeast Minnesota, northeast Iowa, and southwest Wisconsin. This is the final planned spring flood outlook for 2024. This information is the last of three planned spring flood and water resources outlooks providing spring snowmelt and flood potential information for this upcoming spring. The information that goes into this outlook was collected from a number of National Weather Service partners including the United States Geological Survey, US Army Corps of Engineers, Midwestern Regional Climate Center, US Drought Monitor, Climate Prediction Center, and NOAA’s Office of Water Prediction. This outlook is a summary of the past and present basin conditions for parts of southeast Minnesota, northeast Iowa, and southwest into central Wisconsin. ...FLOOD POTENTIAL SUMMARY HIGHLIGHTS… The overall flood risk for the Upper Mississippi River Basin is BELOW NORMAL. ...Past Precipitation… During autumn 2023, it was mainly drier than normal (up to 4” drier than normal) across northeast Iowa, southeast Minnesota, and south of Interstate 90 in western Wisconsin. Meanwhile, it was wetter-than- normal (1 to 6” above normal) north of Interstate 90. Much of this precipitation fell (2 to 7”) from October 23 through October 25. As typical during El Niño, much of the Upper Mississippi River Valley was drier than normal during meteorological winter. Outside of a narrow line through the Trempealeau and Black River basins, the entire region received near to below normal precipitation. Precipitation during autumn and winter was not enough to alleviate the large precipitation deficits that had increased during the 2023 growing season (since April 1). Precipitation departures ranged from 8 to just over 19 along and south of Interstate 90. The driest areas were in northeast Iowa. Due to this, these areas are still experiencing moderate (D1) to extreme drought (D3). The last time that it has been this dry going into a spring was back in 2004. During that year, nearly 60% of the La Crosse Hydrologic Service Area (HSA) was in severe (D2) drought. Since the last outlook, we have not seen enough additional precipitation to tip the flood probability scales the other direction. In fact, we have seen drought expand across the local La Crosse Hydrologic Service area, a total of 8.38% more of our area is now in drought. This trend was also seen upstream of our area across much of central Minnesota. Across the region, precipitation values for the past two weeks have ranged from no precipitation near the Twin Cities up to around 0.75 inches along a line from Decorah, Iowa to Wausau, Wisconsin. ...River Conditions... Overall, the amount of water currently moving through our rivers is below long-term average. Lack of snowmelt runoff this year, due to a well-below normal seasonal snowfall, is the main contributor. ...Soil Moisture and Frost Depths... Last September, most of the region was in a drought status. Since then, despite parts of the area experiencing heavier rains in October and again in December, drought has expanded across the region. Due to the drought, soil moisture across the region is well below normal. Due to the abnormally warm temperatures this winter, frost depths are well below normal for this time of year. Our entire region is free of frost and any future precipitation will be able to absorb into the soils freely. ...Snow Cover and Liquid Water Content... A strong El-Niño this past winter played a big role in one of the warmest winters on record across the Upper Mississippi River Basin. Any snow that the region received this winter has largely melted already, leaving little to no snowpack left for a spring melt runoff. ...River Ice Conditions... The near record-setting warmth this winter has led to rivers being virtually ice free across our region. …Weather Outlook… The above conditions can and often change. The biggest factor affecting spring flood risks is the weather conditions during the sensitive period of melting snow. This year, without the presence of a snowpack, future precipitation is the main (only) driver of any flood risk moving forward. For March, NOAA’s Climate Prediction Center (CPC) latest update on February 29th has shifted the probabilities toward warmer than normal across much of the region. There are equal chances of wetter- , near-, and drier-than-normal. Normal temperatures in March range from 27 to 30°F north of Wisconsin Highway 29 and from 30 to 35°F elsewhere. March precipitation normals range from 1.6 to 2 inches along and north of Interstate 94, and from 2 to 2.4 across the remainder of the area. During the 7 strong El Niños since 1949-50, 4 have been among the warmest third, and the remaining 3 were near normal. Precipitation was highly variable with 4 being among the wettest third, 2 among the driest third, and 1 near normal. Snowfall was also highly variable with 4 among the third least, 2 among the snowiest third, and 1 near normal. For spring, NOAA’s Climate Prediction Center currently shows around a 40 percent chance for above-normal temperatures through March, April, and May. There are equal chances for wetter, near, and drier- than-normal precipitation this spring. The normal precipitation range during these 3 months ranges from roughly 8 to 11 inches of precipitation. This outlook will be updated on March 15th. ...Definitions... In Table 1 below, the current (CS) and historical (HS) or normal probabilities of exceeding Minor, Moderate, and Major flood stages 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. The term minor flooding is used to indicate minimal or no property damage. However, some public inconvenience is possible. The term moderate flooding is used to indicate some inundations of structures and roads near streams. Some evacuations of people and/or transfer of property to higher elevations may be needed. The term major flooding is used to indicate extensive inundations of structures and roads. Significant evacuations of people and/or transfer of property to higher elevations will be needed. ...Table 1--Probabilities for Minor, Moderate and Major Flooding... Valid Period: 03/18/2024 - 06/16/2024 : 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 -------- ----- ----- ----- : --- --- --- --- --- --- :Mississippi River Lake City 16.0 18.0 20.0 : <5 26 <5 8 <5 <5 Wabasha 12.0 14.0 16.0 : 14 61 <5 23 <5 8 Alma Dam 4 16.0 17.0 18.0 : <5 7 <5 6 <5 <5 MN City Dam 5 660.0 662.0 665.0 : <5 28 <5 15 <5 6 Winona Dam 5A 655.0 659.0 661.0 : <5 39 <5 9 <5 5 Winona 13.0 15.0 18.0 : 5 48 <5 24 <5 8 Trempealeau 647.0 649.0 651.0 : <5 37 <5 16 <5 6 La Crescent 641.0 643.0 645.0 : <5 30 <5 14 <5 7 La Crosse 12.0 13.0 15.5 : 5 49 <5 26 <5 8 Genoa 631.0 634.0 636.0 : 8 52 <5 14 <5 7 Lansing 17.0 19.0 20.0 : <5 12 <5 7 <5 <5 Lynxville 625.0 628.0 631.0 : <5 25 <5 9 <5 <5 McGregor 16.0 19.0 22.0 : 8 56 <5 30 <5 10 Guttenberg 15.0 18.0 21.0 : <5 49 <5 16 <5 6 :Zumbro River Zumbro Falls 18.0 24.0 26.0 : <5 11 <5 <5 <5 <5 :South Fork Zumbro River Rochester 14.0 18.0 20.0 : <5 6 <5 <5 <5 <5 :Root River Houston 15.0 17.0 18.0 : <5 9 <5 <5 <5 <5 :South Branch Root River Lanesboro 12.0 16.0 18.0 : <5 5 <5 <5 <5 <5 :Cedar River Lansing 18.0 20.0 22.0 : <5 6 <5 <5 <5 <5 Austin 15.0 18.0 20.0 : <5 7 <5 5 <5 <5 Charles City 12.0 15.0 18.0 : <5 21 <5 8 <5 7 :Turtle Creek Austin 10.5 12.0 14.0 : 7 16 <5 12 <5 <5 :Turkey River Spillville 9.0 11.0 13.0 : 6 35 5 25 <5 13 Elkader 12.0 16.0 20.0 : 16 44 5 15 <5 <5 Garber 17.0 20.0 23.0 : 10 31 6 17 5 7 :Upper Iowa River Bluffton 14.0 16.0 18.0 : <5 <5 <5 <5 <5 <5 Decorah 12.0 13.0 14.0 : <5 <5 <5 <5 <5 <5 Dorchester 14.0 17.0 19.0 : 9 18 7 8 <5 <5 :Trempealeau River Arcadia 8.0 9.0 10.0 : <5 <5 <5 <5 <5 <5 Dodge 10.5 11.0 12.0 : 12 20 6 10 <5 <5 :Black River Neillsville 18.0 20.0 22.0 : <5 <5 <5 <5 <5 <5 Black River Falls 47.0 51.0 55.0 : 24 61 13 32 <5 7 Galesville 12.0 13.0 15.0 : 20 59 12 40 <5 <5 :Kickapoo River La Farge 12.0 13.0 14.0 : <5 <5 <5 <5 <5 <5 Viola 14.0 16.0 18.0 : <5 5 <5 <5 <5 <5 Readstown 11.0 14.0 16.0 : 14 30 <5 <5 <5 <5 Soldiers Grove 13.0 16.0 19.0 : 8 17 <5 <5 <5 <5 Gays Mills 13.0 15.0 17.0 : 23 42 5 7 <5 <5 Steuben 12.0 13.0 15.0 : 6 15 <5 8 <5 <5 :Wisconsin River Muscoda 9.0 10.0 11.0 : <5 18 <5 7 <5 <5 :Yellow River Necedah 15.0 16.5 18.0 : 27 70 8 45 <5 14 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: 03/18/2024 - 06/16/2024 Location 95% 90% 75% 50% 25% 10% 5% -------- ------ ------ ------ ------ ------ ------ ------ :Mississippi River Lake City 6.9 7.3 8.6 10.4 12.7 14.1 15.1 Wabasha 7.5 7.7 8.5 9.5 11.4 12.2 12.9 Alma Dam 4 4.9 5.3 6.3 7.5 9.6 10.9 11.9 MN City Dam 5 651.4 651.7 652.7 654.0 656.4 658.1 659.0 Winona Dam 5A 646.2 646.5 647.6 649.4 651.9 653.7 654.8 Winona 5.7 5.8 6.6 7.6 10.4 12.2 13.3 Trempealeau 640.2 640.5 641.4 642.5 644.5 645.9 646.7 La Crescent 632.5 632.8 634.3 635.8 637.9 639.8 640.2 La Crosse 5.4 5.6 6.4 7.7 9.8 11.6 12.0 Genoa 622.6 623.0 624.9 626.3 628.9 630.8 631.3 Lansing 8.1 8.2 8.6 9.1 11.0 12.5 13.3 Lynxville 614.9 615.2 616.9 618.4 620.9 622.7 623.5 McGregor 8.4 8.7 9.7 11.2 13.8 15.7 16.8 Guttenberg 6.3 7.1 8.8 10.3 12.6 14.2 14.8 :Zumbro River Zumbro Falls 5.7 5.9 6.8 9.1 10.4 13.3 15.3 :South Fork Zumbro River Rochester 3.3 3.6 4.2 5.1 6.2 8.3 11.7 :Root River Houston 3.5 3.7 4.5 5.5 6.9 8.7 14.6 :South Branch Root River Lanesboro 1.7 1.9 2.1 2.5 3.7 7.0 11.9 :Cedar River Lansing 10.5 11.1 11.9 13.3 14.3 15.6 16.5 Austin 4.5 5.5 5.9 7.4 8.9 10.5 11.5 Charles City 3.0 3.4 4.0 5.2 6.7 8.7 11.6 :Turtle Creek Austin 2.0 2.7 3.7 5.5 7.2 8.9 11.6 :Turkey River Spillville 2.1 2.1 2.8 3.8 4.9 6.3 11.0 Elkader 6.6 6.9 7.7 8.5 10.6 13.4 16.1 Garber 7.2 7.6 8.6 10.2 13.2 17.2 23.2 :Upper Iowa River Bluffton 4.2 4.3 4.9 5.8 6.4 7.3 9.8 Decorah 2.5 2.8 3.2 3.7 4.1 6.5 9.1 Dorchester 7.8 8.1 8.8 9.6 10.4 13.2 18.0 :Trempealeau River Arcadia 3.9 4.1 5.1 6.3 6.8 7.6 8.0 Dodge 6.3 6.7 8.1 8.7 9.3 10.7 11.1 :Black River Neillsville 5.7 6.1 7.7 9.1 10.4 12.8 13.5 Black River Falls 38.9 39.9 41.9 44.2 46.5 51.6 52.0 Galesville 6.2 7.0 8.5 10.2 11.7 13.0 13.4 :Kickapoo River La Farge 4.3 4.5 5.2 6.2 7.3 9.1 9.7 Viola 8.7 9.0 9.6 10.2 11.2 13.0 13.9 Readstown 5.5 6.0 6.9 8.4 10.2 11.5 13.0 Soldiers Grove 6.5 6.7 8.3 9.8 12.0 12.9 14.5 Gays Mills 7.9 8.3 9.0 10.9 12.7 13.7 15.0 Steuben 7.5 7.8 8.3 9.6 10.3 11.5 12.8 :Wisconsin River Muscoda 2.5 2.7 3.2 4.2 5.9 7.0 8.1 :Yellow River Necedah 10.9 11.3 12.5 13.7 15.1 16.2 16.6 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: 03/18/2024 - 06/16/2024 Location 95% 90% 75% 50% 25% 10% 5% -------- ------ ------ ------ ------ ------ ------ ------ :Mississippi River Lake City 6.5 6.4 6.3 6.1 6.0 5.8 5.7 Wabasha 7.2 7.2 7.1 7.0 7.0 6.8 6.7 Alma Dam 4 4.5 4.5 4.4 4.3 4.3 4.2 4.1 MN City Dam 5 651.3 651.2 651.2 651.1 651.1 651.0 651.0 Winona Dam 5A 645.9 645.9 645.9 645.7 645.7 645.6 645.5 Winona 5.6 5.6 5.5 5.5 5.5 5.4 5.4 Trempealeau 639.8 639.8 639.7 639.5 639.5 639.4 639.3 La Crescent 631.7 631.7 631.7 631.4 631.4 631.3 631.2 La Crosse 5.1 5.1 5.1 4.9 4.9 4.8 4.7 Genoa 621.5 621.5 621.5 621.0 620.9 620.7 620.5 Lansing 7.8 7.8 7.8 7.8 7.8 7.7 7.7 Lynxville 613.4 613.4 613.4 612.9 612.6 612.2 612.0 McGregor 7.9 7.9 7.9 7.6 7.4 7.2 7.1 Guttenberg 5.0 5.0 4.9 4.2 4.0 3.8 3.7 :Zumbro River Zumbro Falls 5.0 4.9 4.9 4.9 4.8 4.8 4.7 :South Fork Zumbro River Rochester 2.5 2.4 2.4 2.4 2.3 2.3 2.3 :Root River Houston 3.2 3.1 3.0 3.0 2.9 2.8 2.8 :South Branch Root River Lanesboro 1.4 1.4 1.4 1.3 1.3 1.2 1.2 :Cedar River Lansing 9.1 9.0 9.0 9.0 8.9 8.9 8.9 Austin 3.2 3.0 3.0 3.0 2.9 2.9 2.9 Charles City 2.1 2.0 2.0 2.0 2.0 1.9 1.9 :Turtle Creek Austin 1.2 1.2 1.1 1.1 1.0 1.0 1.0 :Turkey River Spillville 1.8 1.8 1.8 1.7 1.7 1.6 1.6 Elkader 5.5 5.4 5.3 5.3 5.1 5.1 5.0 Garber 6.2 6.1 6.0 5.9 5.7 5.7 5.6 :Upper Iowa River Bluffton 3.0 2.9 2.9 2.8 2.8 2.7 2.7 Decorah 1.7 1.6 1.5 1.5 1.4 1.3 1.3 Dorchester 6.8 6.7 6.7 6.7 6.6 6.5 6.5 :Trempealeau River Arcadia 3.3 3.2 3.2 3.2 3.1 3.1 3.1 Dodge 5.3 5.3 5.2 5.1 5.0 4.9 4.9 :Black River Neillsville 3.3 3.1 3.1 3.0 2.9 2.8 2.8 Black River Falls 36.4 36.3 36.2 36.1 36.0 36.0 35.9 Galesville 3.9 3.8 3.5 3.4 3.3 3.2 3.2 :Kickapoo River La Farge 3.0 3.0 2.9 2.9 2.8 2.7 2.7 Viola 7.3 7.3 7.2 7.1 6.9 6.8 6.7 Readstown 4.0 3.9 3.8 3.7 3.6 3.5 3.4 Soldiers Grove 4.8 4.7 4.3 4.0 3.5 3.3 3.1 Gays Mills 6.7 6.6 6.5 6.3 6.1 5.9 5.7 Steuben 6.4 6.3 6.1 5.9 5.7 5.6 5.5 :Wisconsin River Muscoda 1.2 0.8 0.3 0.1 -0.1 -0.2 -0.3 :Yellow River Necedah 9.8 9.7 9.6 9.5 9.4 9.4 9.4 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 and 90 day long-range outlooks of temperature and precipitation. By providing a range of probabilities...the level of rise associated with long-range planning decisions can be determined. These probabilistic forecasts are part of the National Weather Service's Advanced Hydrologic Prediction Service. All of this information is also available in graphical format on the internet at: http://www.weather.gov/lacrosse The next outlook will be issued in late April. $$