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Every spring the National Weather Service (NWS) prepares a series of flood outlooks for the potential of river flooding as a result of snow pack melt.
Each outlook takes into account antecedent conditions and current snowpack levels to anticipate the overall flood risk. The rate and timing of melt, in addition to future precipitation, can alter conditions as well.
These outlooks contain information about the potential for flooding throughout the spring months. The information can help decision makers and those with river interests prepare, in order to protect life and property.
Planned Spring Snowmelt Flood Outlook Release Dates:
Spring Flood Outlook Presentation
The overall risk for flooding this spring is near to slightly above normal along the mainstem of the Mississippi River and its associated tributaries across southeast Minnesota, northeast Iowa, and southwest Wisconsin. The greatest chances of flooding this spring will be along the mainstem of the Mississippi River. The next spring flood outlook release will be on Thursday, February 23rd, 2023. This information is the first 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 partners of the National Weather Service 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 near to slightly above normal. ...Past Precipitation… Autumn 2022 was mainly dry across the La Crosse Hydrologic Services Area. Precipitation amounts ranged from 3.54 inches near Osage, IA (CoCoRaHS) to 11.67 inches near Warrens, WI (CoCoRaHS). This resulted in precipitation deficits of up to 4 inches in western Wisconsin and from 2 to 6 inches in northeast Iowa and southeast Minnesota. These deficits caused moderate (D1) to severe (D2) drought to develop across parts of northeast Iowa, southeast Minnesota, and west-central Wisconsin. Precipitation from the start of the water year (Oct 1st) through February 8th was near normal. Across portions of SE Minnesota and NE Iowa, locations have received 75 to 100 percent of normal. East of the Mississippi across SW Wisconsin, locations have received 100 to 130% of normal precipitation; however, from December 1 through February 8, it has been predominantly wetter than normal across much of the area. Precipitation totals ranged from 1.92 inches at Grand Meadow, MN (COOP) to 5.96 inches near Muscoda, WI (CoCoRaHS). This resulted in precipitation surpluses ranging from near-normal to 3 inches wetter than normal. Both La Crescent Dam 7, MN (5.49 inches) and Steuben, WI (5.44 inches) were the 2nd wettest for the aforementioned time period. Only 2016 was wetter. The above-normal precipitation alleviated the drought across most of the area. At this time, only Floyd County in northeast Iowa still has moderate drought. ...River Conditions... Overall, the amount of water currently moving through our rivers is near the long-term average. Due to drought, our rivers were flowing well-below normal this past fall prior to winter so they should still have a little extra room to absorb runoff this spring. ...Soil Moisture and Frost Depths... Thanks to an early snowpack, frost depths are much more shallow than normal due to above-normal temperatures. There was enough snowpack across the area during the colder periods (around Christmas through the New Year) to limit deeper frosts from developing. Below-normal precipitation in the summer and fall of 2022 across the region allowed for soil moisture content to continue to fall below their long-term averages. This will allow the soils to take on more water than the last few seasons; however, frost depths may initially hinder infiltration, which may allow ponding of water and more runoff, especially if the region experiences a sudden thaw. ...Snow Cover and Liquid Water Content... Snow Water Equivalent (SWE) values across the upper reaches of the Mississippi River Basin are the biggest factor leading towards an above-normal chance of spring melt flooding. SWE amounts across northern and central MN range from 3 to 5 inches. Across parts of west and central Wisconsin, which flows into the Mississippi through the Saint Croix and Chippewa Rivers have between 5 and 7 inches of SWE. These values are in the top 30th percentile and are the primary driver of the slightly above-normal chance of flooding along the Mississippi River. SWE values significantly drop along a line from Austin MN to Wausau WI. SWE values to the south of this line begin to fall below-normal, in the 30th to 50th percentiles. ...River Ice Conditions... This winter has experienced periods of warmer than normal temperatures and shots of arctic air across our region. While this has allowed river ice to develop, there is no indication that the amount of ice is anomalous. The aforementioned warmer periods of temperatures have allowed a slow release of ice along the rivers, with limited ice jams suspected and observed. ...Weather Outlook... The above conditions can and often change. The biggest factor affecting spring flood risks are the weather conditions during the sensitive period of melting snow. A slow and steady melt, with little to no additional precipitation will lower the flood risk significantly. Conversely, a fast warm up, coupled with moderate to heavy amounts of rainfall would significantly increase the flood risk. As we head into early spring, we will see a transition from La Niña to ENSO neutral. While this is the case, the atmosphere will likely behave as La Niña into March. This is important because there is a favored storm track from northeast Arkansas into the eastern Great Lakes during February and March. Since this track can move a bit further northwest at times, the odds were tilted slightly for wetter than normal from February into April for the Upper Mississippi River Valley. As far as temperatures, the Climate Prediction Center is forecasting equal chances for above-, near-, and below-normal temperatures from February into April.
Spring Flood Outlook Presentation
The overall risk for flooding this spring is ABOVE NORMAL along the mainstem of the Mississippi River. The Mississippi tributaries across southeast Minnesota and southwest Wisconsin have NEAR to ABOVE NORMAL chances for flooding this spring. The Mississippi tributaries across NE Iowa have NEAR to BELOW normal chances for flooding this spring. The greatest chances of flooding this spring are on the mainstem of the Mississippi River. The final spring flood outlook will be on Thursday, March 9th, 2023. This information is the second 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 partners of the National Weather Service 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 near to above normal. ...Past Precipitation… Autumn 2022 was mainly dry across the La Crosse Hydrologic Services Area. This resulted in precipitation deficits of up to 4 inches in western Wisconsin and from 2 to 6 inches in northeast Iowa and southeast Minnesota. These deficits caused moderate (D1) to severe (D2) drought to develop across parts of northeast Iowa, southeast Minnesota, and west-central Wisconsin. Precipitation from the start of the water year (Oct 1st) through February 22nd was near normal. Across portions of SE Minnesota and NE Iowa, locations have received 75 to 100 percent of normal. East of the Mississippi across SW Wisconsin, locations have received 100 to 130% of normal precipitation; however, from December 1 through February 21, it has been predominantly wetter than normal across much of the area. Precipitation totals ranged from 2.48 inches at Grand Meadow, MN (COOP) to 6.49 inches near Gays Mills, WI (CoCoRaHS). This resulted in precipitation surpluses ranging from near-normal to 3 inches wetter than normal. Several locations are in the top 10 for the wettest meteorological winter through February 21. This includes: Steuben, WI - 6.06 inches - 2nd wettest La Crescent Dam 7, MN - 5.33 inches - 3rd wettest Rochester, MN - 5.22 inches - 3rd wettest Lancaster, WI - 5.74 inches - 8th wettest Prairie du Chien, WI - 5.46 inches - 8th wettest The above-normal precipitation alleviated the drought across the area. However, there are still areas of abnormally dry (D0) conditions in southeast Minnesota and northeast Iowa. ...River Conditions... Overall, the amount of water currently moving through our rivers is near the long-term average. Due to drought, our rivers were flowing well-below normal this past fall prior to winter so they should still have a little extra room to absorb runoff this spring. ...Soil Moisture and Frost Depths... Thanks to an early snowpack as well as above-normal temperatures, frost depths are much more shallow than normal. There was enough snowpack across the area during the colder periods (around Christmas through the New Year) to limit deeper frosts from developing. With the loss of snow in February, we did see a slight increase in frost depths along and south of Interstate 90. Below-normal precipitation in the summer and fall of 2022 across the region allowed for soil moisture content to continue to fall below their long-term averages. This will allow the soils to take on more water than the last few seasons; however, frost depths may initially hinder infiltration, which may allow ponding of water and more runoff, especially if the region experiences a sudden thaw. ...Snow Cover and Liquid Water Content... *THIS SECTION DOES NOT INCORPORATE SNOWFALL FROM FEB 21ST THROUGH FEB 23RD* Snow Water Equivalent (SWE) values across the upper reaches of the Mississippi River Basin are the biggest factor leading towards an above-normal chance of spring melt flooding. As of the morning of Feb 21st, SWE amounts across northern and central MN range from 4 to 7 inches. Across parts of west and central Wisconsin, which flows into the Mississippi through the Saint Croix, Wisconsin, and Chippewa Rivers have between 5 and 7 inches of SWE. These values are in the top 30th percentile and are the primary driver of the above- normal chance of flooding along the Mississippi River. SWE values significantly drop along a line from Austin MN to Wausau WI. SWE values to the south of this line begin to fall below-normal, in the 30th to 50th percentiles. ...River Ice Conditions... This winter has experienced periods of warmer than normal temperatures and shots of arctic air across our region. While this has allowed river ice to develop, there is no indication that the amount of ice is anomalous. Area river webcams during the last thaw showed ice breakup within the rivers, with no known issues caused by this ice. ...Weather Outlook... The above conditions can and often change. The biggest factor affecting spring flood risks are the weather conditions leading into and during the sensitive period of melting snow. A slow and steady melt, with little to no additional precipitation will lower the flood risk significantly. Conversely, a fast warm up, coupled with moderate to heavy amounts of rainfall would significantly increase the flood risk. As we head into spring, we will see a transition from La Niña to ENSO neutral. While this is the case, the atmosphere will likely behave as La Niña into March. This is important because there is a favored storm track from northeast Arkansas into the eastern Great Lakes through March. Since this track can move a bit further northwest at times, the odds were titled slightly for wetter than normal for meteorological spring for the Upper Mississippi River Valley. As far as temperatures, the Climate Prediction Center is forecasting equal chances for above-, near-, and below-normal temperatures for meteorological spring.
Spring Flood Outlook Presentation
The overall risk for flooding this spring is WELL ABOVE NORMAL along the mainstem of the Mississippi River. The Mississippi tributaries across southeast Minnesota and southwest Wisconsin have NEAR to ABOVE NORMAL chances for flooding this spring. The Mississippi tributaries across NE Iowa have NEAR to BELOW normal chances for flooding this spring. The greatest chances of flooding this spring are on the mainstem of the Mississippi River. This information is the final 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 partners of the National Weather Service 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 near to above normal. The flood risk along the mainstem of the Mississippi River is well above normal. ...Past Precipitation… We have seen at least one significant system a week across the Upper Mississippi River basin in the last month. These systems added to the anomalously large snowpack to the north and their rains brought minor flooding across parts of NE Iowa along the Turkey River. During the meteorological winter (December 1-February 28) of 2022- 23, precipitation totals ranged from 4.36 at Grand Meadow, MN (COOP) to 8.12 near Steuben, WI (COOP). These precipitation values ranged from near-normal to 4 wetter-than-normal. The following locations had their wettest winters La Crescent Dam 7, MN (7.83 inches); Prairie du Chien, WI (7.16 inches); Rochester, MN (6.57 inches); and Steuben, WI (8.12 inches). Precipitation from the start of the water year (Oct 1st) through March 8th was near to above normal. Across portions of SE Minnesota and NE Iowa, locations have received 75 to 100 percent of normal. East of the Mississippi across SW Wisconsin, locations have received 100 to 130% of normal precipitation; however, from December 1 through March 8, it has been predominantly wetter than normal across much of the area. ...River Conditions... Overall, the amount of water currently moving through our rivers is near the long-term average. Due to drought, our rivers were flowing well-below normal this past fall prior to winter; however, recent rains and runoff have brought rivers higher, closer to normal flows. ...Soil Moisture and Frost Depths... Thanks to an early snowpack as well as above-normal temperatures, frost depths are much more shallow than normal. There was enough snowpack across the area during the colder periods (around Christmas through the New Year) to limit deeper frosts from developing. With the loss of snow in February, we did see a slight increase in frost depths along and south of Interstate 90. Below-normal precipitation in the summer and fall of 2022 across the region allowed for soil moisture content to continue to fall below their long-term averages. Recent rains, however, have brought increased moisture in the regions soils. This will allow for more runoff than what was expected a month ago, but soils are not anomalously moist. Frost depths will initially hinder infiltration if there is a sudden thaw, which will allow more runoff. ...Snow Cover and Liquid Water Content... Snow Water Equivalent (SWE) values across the upper reaches of the Mississippi River Basin are one of the biggest factors leading towards an above-normal chance of spring melt flooding. As of the morning of Mar 6th, SWE amounts across northern and central MN range from 4 to 7 inches. Across parts of west and central Wisconsin, which flows into the Mississippi through the Saint Croix, Wisconsin, and Chippewa Rivers have between 5 and 8 inches of SWE. These values are in the top 10 to 20% of the historical record and are the primary driver of the above-normal chance of flooding along the Mississippi River. SWE values significantly drop along a line from Austin MN to Wausau WI. ...River Ice Conditions... This winter has experienced periods of warmer than normal temperatures and shots of arctic air across our region. While this has allowed river ice to develop, there is no indication that the amount of ice is anomalous. Area river webcams during the last thaw showed ice breakup within the rivers, with no known issues caused by this ice. ...Weather Outlook... The above conditions can and often change. The biggest factor affecting spring flood risks are the weather conditions leading into and during the sensitive period of melting snow. A slow and steady melt, with little to no additional precipitation will lower the flood risk significantly. Conversely, a fast warm up, coupled with moderate to heavy amounts of rainfall would significantly increase the flood risk. As we head into spring, we will see a transition from La Niña to ENSO neutral. While this is the case, the atmosphere will likely behave as La Niña through March. This is important because there is a favored storm track from northeast Arkansas into the eastern Great Lakes. Since this track can move a bit further northwest at times, the odds were titled slightly for wetter than normal for meteorological spring for the Upper Mississippi River Valley. During the next 2 weeks, temperatures are forecast to be colder than normal. This will slow down the snow melt in the Chippewa, Minnesota, St. Croix, and upper portions of the Mississippi watersheds. The longer we go into the spring with deep snowpack in these basins, increases the potential for significant flooding on the Mississippi River. If the melt is delayed and significant rainfall is added, we could see more significant flooding. The flood risk numbers are indicating that flooding could rival what was seen in the spring of 2019. Any mentionable precipitation between now and the end of spring thaw within the Upper Mississippi River basin will only increase probabilities for flooding - especially the chances for moderate to major flooding.
Spring Flood Outlook Presentation
The overall risk for flooding this spring is WELL ABOVE normal along the mainstem of the Mississippi River. The Mississippi tributaries across southeast Minnesota and southwest Wisconsin have NEAR normal chances for flooding this spring. The Mississippi tributaries across NE Iowa have NEAR to BELOW normal chances for flooding this spring. The greatest chances of flooding this spring are on the mainstem of the Mississippi River. This information is an update to the 2023 spring snowmelt flood potential outlooks that have been previously provided on a fixed schedule. The information that goes into this outlook was collected from a number of partners of the National Weather Service 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 near to above normal. The flood risk along the mainstem of the Mississippi River is well above normal. ...Past Precipitation… We have seen on average at least one significant system a week across the Upper Mississippi River basin since February. These systems added to the anomalously large snowpack to the north and their rains brought minor flooding across parts of NE Iowa along the Turkey River. During the meteorological winter (December 1-February 28) of 2022- 23, precipitation totals ranged from 4.36 at Grand Meadow, MN (COOP) to 8.12 near Steuben, WI (COOP). These precipitation values ranged from near-normal to 4 wetter-than-normal. The following locations had their wettest winters La Crescent Dam 7, MN (7.83 inches); Prairie du Chien, WI (7.16 inches); Rochester, MN (6.57 inches); and Steuben, WI (8.12 inches). Precipitation from the start of the water year (Oct 1st) through March 22nd was near to above normal. Across portions of SE Minnesota and NE Iowa, locations have received 75 to 100 percent of normal. East of the Mississippi across SW Wisconsin, locations have received 100 to 130% of normal precipitation; however, it has been predominantly wetter than normal across much of the area in the last 30 days - with locations across much of eastern Minnesota and Wisconsin receiving 2 to upwards of 3 inches of precipitation. ...River Conditions... Overall, the amount of water currently moving through our rivers is near the long-term average. Due to drought, our rivers were flowing well-below normal this past fall prior to winter; however, recent rains and runoff have brought rivers higher, closer to normal flows. ...Soil Moisture and Frost Depths... Thanks to an early snowpack as well as above-normal temperatures, frost depths are much more shallow than normal. There was enough snowpack across the area during the colder periods (around Christmas through the New Year) to limit deeper frosts from developing. With the loss of snow in February, we did see a slight increase in frost depths along and south of Interstate 90. Below-normal precipitation in the summer and fall of 2022 across the region allowed for soil moisture content to continue to fall below their long-term averages. Recent rains, however, have brought increased moisture in the regions soils. This will allow for more runoff than what was expected a month ago, but soils are not anomalously moist. Frost depths will initially hinder infiltration if there is a sudden thaw, which would allow more runoff. ...Snow Cover and Liquid Water Content... Snow Water Equivalent (SWE) values across the upper reaches of the Mississippi River Basin is the biggest factor leading towards an above-normal chance of spring melt flooding. As of the morning of Mar 20th, SWE amounts across northern and central MN range from 5 to 7 inches. Across parts of west and central Wisconsin, which flows into the Mississippi through the Saint Croix, Wisconsin, and Chippewa Rivers have between 6 and 8 inches of SWE. These values are in the top 10 to 20% of the historical record and are the primary driver of the above-normal chance of flooding along the Mississippi River. SWE values significantly drop along a line from roughly Austin MN to Wausau WI. ...River Ice Conditions... Ice in the rivers is not expected to play any role in this year's spring flood potential. ...Weather Outlook and Summary... The above conditions can and often change - in fact there has been changes in each of the previous outlooks. The biggest factor affecting spring flood risks are the weather conditions leading into and during the sensitive period of melting snow. Eventually this snow will melt and run into area rivers. The concern for significant flooding stems from how will this melt occur and if there are any significant precipitation events at the same time. A slow and steady melt, with little to no additional precipitation will lower the severity of the flood risk. Conversely, a fast warm up, coupled with moderate to heavy amounts of rainfall would significantly increase the severity of the flood risk. For the remainder of March, NOAAs Climate Prediction Center (CPC) has tilted the odds to favor below-normal temperatures (normal high temperatures are near 50°F and low temperatures are near 30°F) and near-normal precipitation (normal precipitation is around 0.6 inches). For the first week in April, CPC continues to favor below-normal temperatures (normal high temperatures are in the lower to mid-50s and low temperatures are in the lower to mid-30s). Meanwhile, precipitation is expected to be near to wetter-than-normal (normal precipitation is around 0.8 inches). Looking further ahead into mid-April, climate models continue to show that below-normal temperatures (normal high temperatures are in the mid-to-upper 50s and low temperatures are in the mid-to-upper 30s) are likely to continue and precipitation looks to be near- to below normal (normal precipitation is around 0.9 inches). The last time many locations along the upper portions of the Mississippi River saw moderate flooding was April 2019, the last major flooding was April 2001, and set their all-time record flooding was April 1965. Since 1938, La Crosse, WI has seen moderate to major Mississippi River flooding in 13 springs. Looking at the temperatures in the basins that fed the Upper Mississippi River during these springs, the Marches were primarily colder-than-normal (9 springs). March 2023 has been near to colder (up to 4°F colder- than-normal) in the basins that feed the Upper Mississippi River. Precipitation was near-normal in 11 of these Marches and 6 Aprils were near-normal, with 5 Aprils wetter-than-normal. March 2023 has been wetter than normal (up to 1 inch wetter) in the basins that feed the upper Mississippi River.
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