April has been quite a rainy month so far with 1.75 inches falling at the Chicago/Rockford Int’l Airport through 3pm Wednesday. That amount is 160% of normal! While 2/3 of an inch of rain falling as a surplus is a good thing to bring our drought to an end, the forecast is not.
The forecast from the National Weather Service’s GFS model shows 2.41″ of rainfall coming in the next 16 days. That amount is more than we should receive in a typical April, 135% of normal.
Of concern is this pattern of repeated rainfall. With our rivers now flooding in Northern Illinois and Southern Wisconsin, we need this pattern to change in order to get the river levels to level off.
Meteorologists refer to this type of situation as ”high evaporative feedback.” Because our ground is saturated, it will lead to increased evaporation in the days and weeks to come. This will cause storm systems to be wetter than normal, with our models possibly underdoing the rain forecast for the next few weeks. Signals show this pattern will persist for a few weeks, possibly well into May.
With a barrage of storm systems coming through the center part of the United States over the next 1-2 weeks, prepare for rising river levels and increased flooding. Below are a few of the river gauges from this afternoon. You can see all of the levels on the National Weather Service’s Rivers and Lakes Page here.
This post was written by Eric Sorensen on April 10, 2013