October 1-9, 2001

The period of October 1-9 was generally good for harvesting crops, with only one major weather system slowing down the field work. Precipitation for the period was light in the northwestern Midwest, less than 0.25 inches, but reached 1.5 inches or more in a swath from southwestern Missouri to southern Michigan (Figure 7). The precipitation anomaly for the period ranged from 0.5 to 1.0 inch below normal in the dry areas to several inches above normal in the wet areas (Figure 8). This pattern amounted to a percentage of normal variation from 25% or less in Minnesota to greater than 150% in the wet swath (Figure 9). Temperatures for the October 1 to 9 period overall were 1 to 4°F below normal, with the coldest conditions relative to normal in Wisconsin (Figure 10). However, this is somewhat misleading, as the first 4-5 days of the month were quite mild prior to the strong frontal passage on the 5th and 6th. The next three days were well below normal, with the lowest regional temperatures recorded on the morning of October 7 (Figure 11). A hard freeze occurred throughout the northern Midwest, extending southward into southern Iowa and north-central Illinois / Indiana / Ohio. Record low minimum temperatures were set on October 7 at Chicago-O'Hare and Rockford, IL; Dubuque, IA; Cleveland, OH; Jackson, KY; Duluth and International Falls, MN; and Madison, Oshkosh, Green Bay, and Eau Claire, WI. On the morning of the 8th, record lows occurred at Alpena and Flint, MI, and Eau Claire, WI.

Prior to the precipitation on the 5th and 6th, conditions were warm and dry enough in southern Indiana to allow the ignition and spread of five different cornfield blazes in Tippecanoe County. No one was injured, but wind and tall corn stalks made this kind of fire quite difficult to fight, and a middle school had to be hosed-down to prevent the field fire from spreading. The front brought not only much needed rain the Midwest, but also generated the first measurable snows in northern Minnesota, Wisconsin, Michigan, and Ohio. Snowfall totals of 1-3 inches were reported in northern Wisconsin, and up to 7 inches fell in the Upper Peninsula of Michigan. The Marquette, MI NWS Office in Negaunee set a new record for October 6 snowfall of 4.2 inches. The period ended with the approach of another strong Southwestern low pressure center to the region late on the 9th, but most of the precipitation for this event will be reported in the next period, and so it will be discussed next week.