October 1-12, 2000

October began with some warm weather, as a high pressure center gradually moved to the east. The Midwest came under the influence of warm southwesterly winds, and warmed up to a level considerably above normal, especially in the western part of the region. A strong low pressure center and cold front moved through the Midwest on October 4-5, bringing two days of intense rain to the central and eastern portions of the region and colder than normal temperatures everywhere. On the 4th a band of heavy rain developed with an axis extended from central Iowa to Ohio; the rain was even more intense late on the 4th and on the 5th as it sagged southward into Missouri and southern Illinois, Indiana, and Ohio. The total rainfall for these states was a minimum of 1.5 inches, with a swath extended from southern Illinois through southern Indiana receiving more than 3 inches (Figure 7). Very cold air started entering the northwest part of the Midwest by October 4th. The morning low temperatures in Minnesota, Wisconsin, Iowa, and most of Missouri and Illinois averaged below 32 Deg F for the five day period October 6 to 10, and reached below freezing on each of the 5 days at some locations in these states (Figure 8). For the period October 6 to 10, daily average temperatures graded from 6 Deg F below normal in northeastern Michigan to more than 18 Deg F below normal in western Missouri.