First spring flood outlook released, many areas show lower flood risk than normal
Near normal to below average flooding expected across eastern Iowa this spring
CEDAR RAPIDS, Iowa (KCRG) - The first of three flood outlooks for this spring was released Thursday by the National Weather Service, and it generally has good news for eastern Iowa’s rivers.
The NWS is forecasting a near normal to below normal flood risk across the Upper Mississippi River and its tributaries this spring.
Snowpack is generally below average for the basin which is a major factor in the lower flood risk. Snow moisture content is below normal locally, though values are above normal in the upper portions of the Mississippi basin in far northern Minnesota and Wisconsin. Dier than normal soils and near-normal river levels are also contributing to the lower risk as spring rains will be able to be absorbed and contained. Frost depths are at about 10″ -25″ in most of the Upper Mississippi Valley which are around normal for this time of year, though they are below normal in the Quad Cities.
In the Cedar Rapids and Iowa City areas, the Cedar and Iowa Rivers are likely to see below-normal flooding. Flooding along with the Mississippi ad Dubuque is generally near to below normal.
There is a low to moderate risk for ice jams. This could cause localized, but usually fleeting, flooding issues, especially in river bends or areas that are especially prone to ice jam development.
Any additional heavy precipitation or rapid snowmelt could still change this outlook as it is based on current observations and forecasts. The long-range outlooks for March, April and May suggest slightly above normal rainfall in eastern Iowa.
For additional information, the NWS has some more details here. The next flood outlook will be released in 2 weeks on February 24.
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