FGUS73 KDLH 141603 ESFDLH MNC001-017-021-031-035-061-071-075-115-137-WIC003-007-013-031- 051-099-113-129-281700- PROBABILISTIC HYDROLOGIC OUTLOOK NATIONAL WEATHER SERVICE Duluth MN 1100 AM CDT Thu Mar 14 2024 ...Spring Flood and Water Resources Outlook... This outlook covers NE Minnesota and NW Wisconsin for river forecast points on the headwaters of the Mississippi, Chippewa, St. Croix, and Rainy Rivers. ...Changes Since Previous Issuance February 29th... Precipitation over the past two weeks across the region was generally 0.5 to 1 inches below normal. Temperatures were well above normal. Dry conditions have pushed chances for spring flooding lower than the previous issuance. ...Current Conditions... Precipitation since October has been near normal across the region except north central Wisconsin and Lake and Cook counties where it has been below normal. Much of the precipitation fell as rain and runoff was observed over the last week of December. No frost was present after the late December rains thus in addition to the rainfall runoff some rainfall percolated into the soil which soon re- froze. A widening area of moderate drought conditions continue expanding across the entire area. Severe drought exists in northern Wisconsin. If dry conditions continue further drought development is likely. The lack of snowpack is the main driver of the spring river forecasts. Record low snowpack is occurring across NE Minnesota and NW Wisconsin. Without an insulating snowpack the frost has reestablished to a depth of 22 inches. Frost depth is important because any heavy rainfall on frozen ground could generate efficient and rapid runoff. Rain on frozen ground is not well accounted for in the model solutions below. Rivers in the area are mainly ice free due to the recent warm weather and are displaying normal to below normal flow. However without well above normal precipitation river levels will remain steady or decrease then fall below normal as we will not see rise from snowmelt. ...Climate Outlook... Looking ahead at precipitation chances we see a signal for above normal precipitation for the period March 21 to 27. Temperature outlooks for the next two weeks indicate below normal temperatures. The Climate Prediction Center will publish the April outlook on March 25th. ...Below Normal Chances of Spring Flooding Across the Area... 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 more 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: 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 -------- ----- ----- ----- : --- --- --- --- --- --- :Prairie River Taconite 10.0 12.0 13.0 : <5 <5 <5 <5 <5 <5 :Mississippi River Aitkin 13.0 15.0 18.0 : 11 54 <5 33 <5 7 Fort Ripley 10.5 12.5 26.0 : 11 43 <5 20 <5 <5 :St. Croix River Danbury 7.0 8.5 10.0 : <5 8 <5 <5 <5 <5 :Snake River Pine City 9.0 10.0 11.0 : <5 10 <5 5 <5 <5 :St. Louis River Scanlon 10.5 11.0 13.0 : <5 5 <5 <5 <5 <5 :Nemadji River Nemadji R nr Supe 24.0 26.0 28.0 : <5 <5 <5 <5 <5 <5 :Tyler Forks Mellen 9.0 10.0 12.0 : 12 35 5 25 <5 5 :Bad River Odanah 16.0 18.0 20.0 : <5 <5 <5 <5 <5 <5 Odanah 8.5 9.5 10.5 : <5 6 <5 <5 <5 <5 :South Kawishiwi River Ely 6.5 7.5 8.5 : <5 25 <5 12 <5 <5 :Little Fork River Little Fork 22.0 24.0 26.0 : <5 <5 <5 <5 <5 <5 :Vermilion River Crane Lake 14.0 16.0 18.0 : <5 14 <5 <5 <5 <5 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% -------- ------ ------ ------ ------ ------ ------ ------ :Prairie River Taconite 3.3 3.5 4.2 5.1 6.0 7.5 8.2 :Mississippi River Aitkin 5.2 5.7 7.7 9.3 11.7 13.5 14.5 Fort Ripley 4.6 5.1 6.5 7.5 9.2 10.7 12.3 :St. Croix River Danbury 1.3 1.6 2.2 3.0 4.0 5.0 5.5 :Snake River Pine City 3.7 4.2 4.8 5.5 6.5 7.8 8.1 :St. Louis River Scanlon 4.4 4.7 5.2 5.8 6.7 7.7 8.9 :Nemadji River Nemadji R nr Supe 8.0 9.8 11.6 14.4 18.5 21.9 22.7 :Tyler Forks Mellen 4.8 5.1 5.7 6.7 7.5 9.3 10.2 :Bad River Odanah 4.1 4.7 5.4 6.6 7.9 10.9 12.3 Odanah 2.9 3.1 3.5 3.9 4.7 6.4 7.0 :South Kawishiwi River Ely 3.1 3.5 3.9 4.4 4.9 5.5 5.8 :Little Fork River Little Fork 3.9 4.1 5.3 6.2 7.3 9.5 12.0 :Vermilion River Crane Lake 7.3 7.3 8.3 9.7 10.7 11.9 12.5 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% -------- ------ ------ ------ ------ ------ ------ ------ :Prairie River Taconite 3.2 3.1 3.0 2.9 2.7 2.4 2.3 :Mississippi River Aitkin 5.1 5.0 4.5 3.6 2.6 2.0 1.7 Fort Ripley 4.6 4.6 4.5 4.2 3.8 3.5 3.4 :St. Croix River Danbury 0.9 0.9 0.9 0.9 0.8 0.8 0.8 :Snake River Pine City 3.0 3.0 3.0 2.9 2.8 2.8 2.8 :St. Louis River Scanlon 3.9 3.8 3.6 3.5 3.4 3.3 3.2 :Nemadji River Nemadji R nr Supe 4.1 4.0 3.9 3.9 3.8 3.7 3.6 :Tyler Forks Mellen 3.5 3.5 3.4 3.3 3.2 3.1 3.1 :Bad River Odanah 2.7 2.6 2.6 2.4 2.4 2.3 2.2 Odanah 2.3 2.2 2.2 2.1 2.1 2.0 2.0 :South Kawishiwi River Ely 2.3 2.3 2.3 2.2 2.2 2.2 2.1 :Little Fork River Little Fork 3.7 3.6 3.5 3.2 2.9 2.1 1.7 :Vermilion River Crane Lake 7.0 6.9 6.7 6.4 6.0 5.4 5.2 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/dlh for more weather and water information. For additional information on stream flow conditions for USGS locations please reference https://dashboard.waterdata.usgs.gov For additional information on stream flow conditions at MNDNR sites www.dnr.state.mn.us/waters/csg/index.html or www.climate.umn.edu/dow/weekly_stream_flow/stream_flow_weekly.asp For more information on climate outlooks reference www.cpc.ncep.noaa.gov The is the final Spring Flood Outlook of 2024. $$