May 1-10, 2002: Flooding Rains in the Midwest.

The first 10 days of May brought flooding rains and severe weather to the southern half of the Midwest. Most of Missouri, southern Illinois, and southern Indiana received more than 4 inches of rain on average (Figure 5), with some smaller regions receiving twice that amount. Precipitation totals exceeded 300% of normal over the area described above (Figure 6), as the dividing line between warm and cool air masses constantly oscillated across the region. Temperature departures reflect this, with a wide area near normal in the middle latitudes of the Midwest, and temperatures ranging from more than 4°F above normal in Kentucky to more than 10°F below normal in northern Minnesota for the period (Figure 7). Drought is not a concern presently in the Midwest, as even western Iowa and Minnesota are receiving rain that should further ameliorate drought in that area (Figure 8, National Drought Mitigation Center, NDMC). Flooding, saturated fields, and planting rates far behind normal have come to the fore as the main concerns in the Midwest, along with outbreaks of violent weather.

River flooding has now reached serious proportions in Missouri, Illinois, and Indiana. More than two dozen gauge sites along rivers are now more than 5 feet above flood stage, and three locations are more than 10 feet above flood stage (Figure 9, National Weather Service, NWS). Typical of conditions along the smaller rivers is the South Fork of the Sangamon River in central Illinois. Flow peaked well above 28 feet on the 10th, which is 10 feet above the flood level near Rochester, IL (Figure 10, U.S. Geological Survey, USGS). Along the Mississippi, the river is rising more slowly, gathering the great volume of excess water falling in its watershed. River levels at Chester, IL, were more than 7 feet above flood stage and still rising on the 10th (Figure 11, USGS). Thousands of acres of farmland are flooded near rivers, and many more tens of thousands of acres are inaccessible to farm equipment due to the wetness. Illinois has planted only 30% of its corn acres by May 5th, which is less than half of the average of the previous five years, 61%.

During the first 10 days of May, federal disaster declarations where made which covered April snow melt / rain flooding in northern Michigan, April 24-28 severe storms and flash flooding damage in Missouri, and April 27-28 severe weather and flooding in Kentucky. Some of these declarations were later expanded to cover the events on May 2-3 and May 8.