Heavy rain back in the forecast this week means two possible scenarios are emerging in regards to how this new moisture will interact with the ongoing major flooding on the Mississippi River.
Taking a look at the status of the soil moisture, it's easy to see why our flood threat remains high. The Mississippi River is surrounded by soils that are completely saturated running all the way from Minnesota to Southern Illinois. All of this due to the active winter with higher than normal snowfall that kept the ground wet through the season and of course the fact that we've experienced a number of rainfall events all across the region, too.
When the soils are completely saturated, it means that any new rainfall is going to immediately run off into creeks, streams, and rivers. Think of the ground as a soaked sponge that you just took out of a sink full of water. You can't add any more water to it. You can leave it on the counter and it will eventually dry out some, but once you add more water, it immediately becomes full again. That is exactly what is going on with the soil here in the Quad Cities. We just can't seem to hang onto a nice, long stretch of dry days to allow the ground to soak in the moisture.
The key to how high the rivers will rise again is all tied to rainfall; how much falls and where the bulk of it does so.
If the heavy rains fall to our immediate north, rises in river levels can be expected in just a couple of days after the heavy rains come to an end. If the heavy rains land right here in the Quad Cities, flash flooding will be likely along with rapid rises in river levels.
Because of the saturated conditions, the risk for flash flooding will also be on the rise as more water drops on top of already full soil.
We'll continue tracking this situation as the rain unfolds this week.
Meteorologist Andrew Stutzke
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