CLINTON — Flood warnings have plagued the Gateway area for much of May so far and it looks like the National Weather Service doesn’t have plans to lift those warnings anytime soon.
The Mississippi River rose to 15.62 feet on Thursday, beginning a climb that is expected to crest Sunday at nearly 17 feet. Minor flood threats are usually issued at 16 feet; but, despite the rising water levels, the threat may not be a cause for urgent action.
According to Maren Stoflet, Quad-City based National Weather Service hydrologist, several factors play into the issuance of flood warnings.
“It varies for a few different reasons,” Stoflet said. “On the main stem of the Mississippi, often there is a longer amount of time to consider. We use our rainfall and take into account tributaries that drain into the river, so there’s a little bit more of a leg there. For the Mississippi we tend to wait until we get that crest within forecast period before we issue the warnings.”
Many of the warnings being issued this week are due to heavy rainfall that saturated both Wisconsin and Minnesota in the past two weeks. As that collection of rain begins to move south along the Mississippi, it has now started to cause problems and potential concerns for Clinton and most of the greater Quad-City area.
But because the possibility of damage is moderate, the area remains only under a minor flood warning.
Stoflet explained the National Weather Service defines flood warnings in four specific categories. Those categories are minor flooding, moderate flooding, major flooding and record flooding.
“At each forecast site we issue warnings based on impacts on those gauge locations and then upstream and downstream a little ways. If we get too much further, then the nature of the river can change so we like to keep things close to the gauges,” she said.