Warmer Temps Bring Flooding Concerns
February 17th – As temperatures slowly climb above freezing, many Midwestern residents are ready to rejoice. But warmer temperatures could mean trouble for area waterways as snow begins to melt and the potential for flooding increases.
According to the National Weather Service Hydrologic Outlook, current snow depths range from 8 to 18 inches, with more accumulation expected early this week. The water equivalent of the snow pack is estimated to be between 1 and 4 inches, with higher amounts mainly near the Wisconsin state line.
While the amount of snow is problematic, the frigid temperatures this winter are also reason for concern. Under all that snow, the ground remains frozen, with frost depths ranging from 12 to 16 inches. The deep frost layer can inhibit the melting snow from infiltrating the ground, causing increased runoff into rivers and streams. The National Weather Service says overnight temperatures Tuesday and Wednesday are expected to dip below freezing, which could slow the melting, and allow waterways time to absorb the runoff. The potential for flooding could increase later in the week as temperatures are likely to remain above freezing for two to three days.
Another concern is the amount of ice cover on area lakes and rivers. Many smaller bodies of water are reported to be completely covered by ice. As the snow melt causes the water level to rise, that ice cover will be pushed upward and broken apart. Smaller chunks of ice moving downstream can lodge together and create an ice dam, which could lead to significant flooding. Officials are cautioning residents who live near rivers or flood prone areas to closely monitor waterways in the coming weeks.