NWS: Risk of 2017 Spring Flooding Is ‘Normal’
The 2017 spring flood outlook is “normal,” according to a report by the National Weather Service Chicago.
The outlook rates the probability of spring flooding for streams within the NWS-Chicago Hydrologic Service Area, which includes Illinois river tributaries in northeast Illinois and northwest Indiana and is based on hydrologic conditions including the current soil moisture, snowpack and streamflow conditions.
The NWS-C is quick to note that hydrologic conditions can change rapidly, and Kane County isn’t out of the woods regarding potential flooding.
“The amount of rainfall or additional snow and subsequent snowmelt in the coming weeks will determine the severity of any future flooding,” the report said. “Ice jams and ice jam flooding remain possible and can result in rapid rises in water levels in a very short time.”
Right now, streamflow on rivers in northwestern Illinois is slightly above normal, largely due to upstream snowmelt.
The good news? As of Feb. 16, there is no snowpack, there is no ice on area rivers and soil moisture levels are presently near normal.
The six-day outlook valid from Feb. 21 to Feb. 25 indicates above-normal temperatures and slightly-above-normal precipitation. The latest outlook for the month of March indicates equal chances of above- or below-normal temperatures and precipitation.
Given the the expected conditions for above-normal temperatures for the next few weeks, any flooding risk would likely be associated with locally heavy rainfall due to thunderstorms, the report said.
SOURCE: National Weather Service Chicago
2017 Spring Flood Outlook