July 18-24, 2001:

The dry pattern of preceding weeks reversed during the July 18-24 period (Figure 16). Most of the Midwest received normal to above normal precipitation for the week. A persistent pattern of hot, humid conditions placed much of the Midwest under the threat of thunderstorms on each day of the period, with a few locations receiving well above normal amounts (Figure 17). At the beginning of the period, July 17 to 18, a group of training thunderstorms brought heavy rain to southeastern Indiana and southwestern Ohio. Amounts up to 6 inches fell in just a few hours, leading to the deaths of 3 people in Cincinnati suburbs (Figure 18, NWS). The convective precipitation was widespread over the next few days, but consistently returned to southeastern Missouri and west-central and southwestern Illinois from July 18-20. Some locations in a narrow north-south corridor received up to 8 inches of rain during the period (Figure 19, NWS). Finally, at the end of the week, heavy rains occurred in southern Minnesota and northern Iowa. Besides benefitting from the rain that did not runoff, these areas suffered spotty crop damage from wind and hail. A smaller but by no means less intense set of storms moved through central and eastern Illinois the evening of July 23rd, also bringing some crop damage due to 40-60 mph straight-line winds (Figure 20, Storm Prediction Center). Only parts of Michigan and eastern Ohio received far less than normal rain amounts this week, causing intensified concern for dryness affecting yields in these areas. Missouri was dry this week, too, but that was beneficial after massive rains in previous weeks. The rain, except in the three sub-areas mentioned, was not sufficient to lift the abnormally dry classification given to much of Iowa, Minnesota, Wisconsin, and Illinois last week, and dryness actually expanded in Michigan and Ohio (Figure 21, National Drought Mitigation Center). Finally, to compound matters, excessive heat in the Great Plains and much of the Midwest may have affected crop fertilization in some locations, and caused a number of heat-related deaths in the region (see below). Temperatures were 4-8°F above normal over most of the Midwest, except for the Ohio Valley and Kentucky, where clouds and fog held temperatures near normal (Figure 22).