Spring Flood Outlook #3

Key Points

• Near normal spring flood risk for the Mississippi River (decreased from Outlook #2). 
   
• Near to slightly below normal spring flood risk for local tributary rivers (little change from Outlook #2). 

• Future precipitation events and rate of snowmelt in the upper Mississippi basin will be the main factors in determining the occurrence and severity of any flooding this spring.   

Details 

The spring flood risk is near normal for the Mississippi River, and near to slightly below normal for local tributary rivers across the NWS Quad Cities Hydrologic Service Area. The flood risk has decreased slightly on the Mississippi River, compared to the second outlook, with little or no change noted in flood probabilities for area tributary rivers.

While the overall risk of spring flooding is not high, this does not mean that flooding will not occur. This will be determined by key factors including future precipitation events, and snowmelt in the Upper Mississippi basin.

Some factors contributing to the near normal to decreased risk include: 1) Near to below normal soil moisture and winter precipitation.  2) Lack of widespread or deep snowpack, with the exception of the upper reaches of the Mississippi River basin.  3) Near normal river

levels. 

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Use the links below to find the Graphical Probabilities and the Numerical Probabilities, respectively.
 

Graphical Hydrologic Outlooks	Spring Flood Risk One-Pager (PDF)   (Mar 10th, 2022)	Statistical Hydrologic Outlook   (Mar 10th, 2022)
Images below are examples which link to the Wapsipinicon River near DeWitt. Find all other locations in the Quad Cities Hydrologic Service Area in the drop down menu below.       Select Location: Mississippi River at Dubuque L&D 11Mississippi River at DubuqueMississippi River at Bellvue L&D 12Mississippi River at Fulton L&D 13Mississippi River at CamancheMississippi River at Le Claire L&D 14Mississippi River at Rock Island L&D 15Mississippi River at Illinois City L&D 16Mississippi River at MuscatineMississippi River at New Boston L&D 17Mississippi River at KeithsburgMississippi River at Gladstone L&D 18Mississippi River at BurlingtonMississippi River at Keokuk L&D 19Mississippi River at Gregory LandingMaquoketa River at ManchesterMaquoketa River at MaquoketaWapsipinicon River at IndependenceWapsipinicon River at AnamosaWapsipinicon River at De WittCedar River at VintonCedar River at Cedar RapidsCedar River at ConesvilleIowa River at MarengoIowa River at Iowa CityIowa River at Lone TreeIowa River at Columbus JunctionIowa River at WapelloIowa River at OakvilleEnglish River at KalonaSkunk River at SigourneySkunk River at AugustaDes Moines River at KeosauquaDes Moines River at St FrancisvilleFox River at WaylandPecatonica River at FreeportRock River at ComoRock River at JoslinRock River at MolineGreen River at GeneseoLa Moine River at Colmar   Go

Current/Forecast River Conditions

Current Conditions	Forecast Conditions	Long-Range Outlooks

Link To Advanced Hydrologic Prediction Service (AHPS) and Additional River Forecast Resources

Flood Category Definitions

• Minor Flooding - minimal or no property damage, but possibly some public threat or inconvenience.
• Moderate Flooding - some inundation of structures and roads near streams. Some evacuations of people and/or transfer of property to higher elevations may be necessary.
• Major Flooding - extensive inundation of structures and both primary and secondary roads. Usually significant evacuations of people and/or transfer of property to higher elevations.  

What Are The Risk Factors For Flooding? 

Many factors are have been considered when determining the overall flood risk for the Spring, with the combination of these influences factoring into the final determination. These factors are discussed in detail below.

Seasonal Precipitation

Little to no change has been observed for the local rivers since the second spring flood outlook has been released.  There remains an increased threat in this category for the Mississippi River. 

Precipitation this winter has averaged below normal for all of the NWS Quad Cities Hydrologic Service Area (HSA). Heading north, below normal precipitation has been observed up through southern Minnesota and southwest Wisconsin, but trends above normal around the Twin Cities into northern Minnesota and Wisconsin especially with recent heavy snows.

Over the past month, heavy snow was observed in the upper Mississippi River basin with snowfall amounts of a foot to as much as thirty inches observed from north central Minnesota to the south shores of Lake Superior.  This adds to the already above normal precipitation to the area, which is leading to an increased threat from this category for Mississippi River flooding.  Climatological outlooks for the next month continue to suggest probabilities favoring above normal precipitation in the upper Mississippi River Valley, which will keep this category at an increased threat for the Mississippi River. 

Below you will find graphics of the precipitation accumulated this winter season (left) and how this amount of moisture compares to normal in percentage (right). These graphics are courtesy of the Midwest Regional Climate Center.

River Conditions

Streamflow analysis from the United States Geological Survey (USGS) indicates the majority of the Upper Mississippi River watershed has rivers running near to slightly above normal.  Plenty of storage still exists, which will help in the event of a heavy precipitation event in the future, as the rivers will be able to hold more water than if river levels were high. 

Iowa	Illinois	Missouri

Soil Conditions

A few snow and rain systems over the past couple of weeks has resulted in some recharge of surface moisture from central into northeast Iowa and much of central and southern Wisconsin, where the heavier precipitation amounts have been favored.  Despite this recent change, soils overall continue to remain drier than normal across much of the Mid and Upper Mississippi River watershed, with the driest soils being indicated over portions of east central Iowa into northwest Illinois.  Soil moisture remains near to above normal throughout the northern portion of the Mississippi basin, with snowmelt and periodic bouts of precipitation.      

Below normal soil moisture over most areas will create additional storage for spring rains and any additional snow and melt, as frost depths decrease. 

Snow Cover and Liquid Water Content

Snow water equivalent analysis from the National Operational Hydrologic Remote Sensing Center (NOHRSC) indicates variable conditions across the Mississippi basin. Snow moisture content is below normal in the local area, and northward into southwest Wisconsin and southeast Minnesota. However, values remain above normal in the upper reaches of the Mississippi basin.  In this area, snow depth ranges from 12-20 inches.  Much of the snow water equivalent ranges between 2 to 4 inches of liquid, with the areas with the deeper snow pack holding 4 to 6 inches of liquid. The flood threat in the mainstem Mississippi from snow water equivalent will be driven by the rate of snowmelt in the upper reaches. For area tributary rivers, snow water equivalent is very low.  Area tributary rivers have a below normal threat for flooding due to snow cover and liquid content, but chances for flooding along the Mississippi have increased a little due to the additional snowpack received this week in the north.

Current Snow Depth               Current Snow Water Equivalent

Images courtesy of the National Operational Hydrologic Remote Sensing Center (NOHRSC)

Frost Depth

Little to no change has been observed since the first spring flood outlook was issued. 

Current frost depth analysis from the North Central River Forecast Center (NCRFC) map (data taken from the U.S. Army Corps of Engineers (USACE), National Weather Service (NWS), and Minnesota) shows frost depths around 10 to 30 inches across much of the Upper Mississippi River Valley.  Per analysis from the Minnesota State Climatologist, these values are around normal for this time of year.  Some areas, including the Quad Cities, have 
lower frost depths as early snow cover helped mitigate colder temperatures penetrating into the surface.  

Frost Depths - North Central River Forecast Center

Regional Frost Depths as of March 10, 2022

Ice Jam Flooding

The threat of ice jam flooding remains decreased for breakup ice jams. 

Drought

According to the U.S. Drought Monitor, much of the Upper Midwest is experiencing Abnormally Dry (D0) to Moderate (D1) drought 
conditions with pockets of Severe (D2) drought conditions.  This will contribute to a reduced threat for flooding, as there will be 
more storage available in the soils to handle additional snowmelt and spring rains. 

Additional Information

2022 Spring Flood Outlook #3                 Document

River and Streamflow Information:

• National Weather Service: water.weather.gov
• US Geological Survey: water.usgs.gov/waterwatch
• Corps of Engineers: rivergages.com 

Flood safety and flood insurance information:

• NWS Flood Safety: www.floodsafety.noaa.gov
• National Flood Insurance Program: www.floodsmart.gov

Precipitation, temperature, and soil moisture information:

• National Operational Hydrologic Remote Sensing Center: www.nohrsc.noaa.gov
• NWS Graphical 7-Day Forecast: https://graphical.weather.gov/sectors/uppermissvly.php
• NWS Climate Prediction Center: www.cpc.ncep.noaa.gov
• US Drought Portal: www.drought.gov 

Questions or Comments

If you have questions or comments about this spring flood and water resource outlook please contact:

National Weather Service Quad Cities Hydrology Team
9040 Harrison St
Davenport, IA 52806
Email: cr.dvn-hydro@noaa.gov