Chicago, IL

Weather Forecast Office

Spring Flood Outlook for Northeast Illinois and Northwest Indiana

Outlook Valid
Spring 2022 (March-May)

Last Updated
March 10, 2022

Based on current conditions, the risk of flooding ranges from below average to near average.

The spring flood outlook is updated each February and March. Next scheduled update Spring 2023.

Risk Factors for Spring Flooding

To determine the relative risk of spring flooding, numerous factors are considered including snow cover, soil moisture, and current river conditions. A significant snow cover with high water content can increase the chances of flooding once warmer weather melts the snow. Elevated soil moisture conditions reduce the amount of rainfall that is soaked up by the ground and increase the amount of water that then runs off into area streams. Above average river levels reduce the river rise required to reach flood stage, while below average river levels would require an increased amount of river rise to reach flood stage.

Spring Flood Outlook 2022

Winter 2021-2022 Review

Fall 2021 Review

Spring Flood Risk Factors

Here is a general overview of spring flood risk factors across northeast Illinois and northwest Indiana river basins.

Risk Factor	Has effect on...	Current Condition	Effect on Flood Risk
Fall/Winter River Levels	Space in river for additional streamflow.	Below Average to Above Average	Decrease/Increase
Fall/Winter Soil Moisture	Space in soil for additional infiltration.	Below Average to Above Average	Decrease/Increase
Winter Precipitation	Snow cover, the amount of water available for spring melt.	Below Average to Near Average	Decrease/No effect
Winter Temperatures	Frost depth, the possibility that infiltration could be blocked by frozen ground.	Near Average	No effect
Spring Precipitation	Amount of water headed to area rivers.	-	-
Spring Temperatures	Rate of melt for snow cover.	-	No effect Most snow cover is melted, so temperatures will not play a major role.

Valid March 10, 2022.

Current Snow Cover and Snow Water Equivalent

Modeled snow cover across area river basins ranges from 0 to 2 inches across the area, which contains 0 inches to 0.25 inches of water equivalent. The deepest snow cover is in northwest Illinois and southern Wisconsin. Snow cover is low enough that it will not be a major factor in spring flood risk.

Valid March 9, 2022. Click here for the latest snow cover information.

Current Soil Moisture and Frost Depth

Modeled soil moisture values across the area range from below average to near average. Values are the lowest in northern Illinois, at the 5^th to 10^th percentile for this time of year.

Frost depth ranges from 0 to 25 inches across area river basins, with the deepest frost depth values reported in isolated parts of southern Wisconsin. Even areas with relatively deep frost depth have several inches of near-surface thaw, which will limit the impact of frozen ground on spring flood risk.

Valid March 9, 2022. Click here for the latest soil moisture information from the Climate Prediction Center.

Current River Conditions

River streamflow across the area ranges from near average to above average. Streamflow has generally decreased across the area since the last outlook, and will have only a limited impact on spring flood risk.

River ice spotters, river gauges, and satellite imagery indicates that area rivers are generally ice free. There is little-to-no risk of additional ice jam flooding this spring.

Valid March 9, 2022. Graphics update daily. Click here for the latest streamflow conditions from the USGS. Click here for the latest river ice spotter reports.

Spring Weather Outlook

The long term (next couple months) outlook from the Climate Prediction Center indicates generally near average temperatures favored during March. The outlook indicates above average precipitation is slightly favored for March, especially in northwest Indiana.

Although snow cover, soil moisture, and recent river levels can provide some indication of the relative risk of spring flooding, any weather system that produces heavy rainfall could cause flooding. Spring flood outlooks are not able to assess the risk of flooding due to heavy rainfall more than a week or so in advance.

Detailed Flood Outlook

Relative flood risk for river forecast locations can be viewed on the Advanced Hydrologic Prediction Service (AHPS) page for our area.

Temperature

Temperatures for winter 2021-2022 averaged about 1F below to 1F above average in northeast Illinois and northwest Indiana. There was a large range in winter temperatures across the season, with December being generally warmer than average and January generally colder than average.

Precipitation

Precipitation for winter 2021-2022 averaged 3 inches below to 2 inches above average in northern Illinois. Precipitation was highest in northern Indiana.

Snowfall

The first measurable snowfall (>0.1 inches) across northeast Illinois and northwest Indiana (right) occurred later than average, with a few locations seeing minor snowfall by late November, but other locations not seeing snowfall until near the end of December.

As of March 9, 2022, the season-to-date snowfall ranged from just over 12 inches to near 36 inches across northern Illinois and northwest Indiana, with the highest values near Lake Michigan. Observed snowfall ranged from slightly below average in northwest Illinois to slightly above average near Lake Michigan.

River ice conditions in January caused a few minor ice jams but no flooding. Very heavy ice cover continued into early February. By late February, break-up ice jams were noted on several rivers, including the Kankakee and Vermilion.

Temperature

Temperatures were above average to much above average across northeast Illinois and northwest Indiana during fall 2021. Almost all areas experienced temperatures at least 2F warmer than average.

Precipitation

Precipitation ranged from below average in northern Illinois to above average in east central Illinois and northern Indiana during fall 2021. Portions of northwest Indiana experienced precipitation about 125-150% of average, while precipitation in northern Illinois was 50-75% of average. Almost all areas were within 4 inches of the average.