October 2000
Temperature and Precipitation Anomalies.
The Midwest averages of temperature and precipitation for October indicate that the month was warmer (Figure 1) and drier (Figure 2) than normal in every one of the nine states in our region. For the month as a whole, the Midwest had its 27th warmest and 37th driest October. However, this is somewhat misleading, as the first half of the month was several degrees cooler than normal everywhere except in Michigan (Figure 3), and wetter than normal in some locations, especially the central Midwest (Figure 4). During the second half of the month, though, temperatures were 6-10 Deg F above normal over most of the region (Figure 5), while precipitation totals were less than 25% of normal over large areas of the central Midwest (Figure 6).
Soil moisture ratings at the beginning of October were beginning to dry somewhat region-wide. In some isolated areas, farmers have had difficulties with moist soil conditions during harvesting, especially from east of central-southern Illinois to Ohio. Overall U.S. corn quality stayed steady as the harvest was completed, and all states in the Midwest except Iowa and Minnesota were at or above 70% good/excellent. Soybean quality ratings were closer to the 60% good/excellent range at the end of the growing season. As farmers got into the fields, they found more damage than expected from earlier in the summer. A very strong cold front that passed through the region on October 3-4 complicated harvest for some by causing some additional lodging to corn not yet harvested at that date.
A series of dry weeks dominated the last few weeks of October in the
Midwest, leading to some concern about the renewal of drought in the
northern and central portions of the region. Soil moisture levels are
considerably below normal in areas of Wisconsin, Michigan, and Illinois
that have not been in drought status since early summer 2000, along
with the already dry parts of Iowa, Minnesota, and the southern edge
of the Midwest (Figure 13, Climate Prediction
Center). These abnormally dry soil moisture conditions have raised
some concerns for winter wheat planting at the end of October. Some
of the northwestern areas of the Midwest are having difficulties with
the planting and germination of winter wheat this fall due to dryness.
During the strong storm and frontal passage on October 4th and 5th, the coop station in Casey, IL, received 6.43 inches of rain in one 24-hour period, which is an event with a return interval of greater than 50 years in that location. This area has been very wet since the regional drought broke in mid-May (Figure 14); Casey is 20.88 inches above normal for rainfall in the period May 15 to October 10, 2000. Because of high soil moisture levels, runoff was rapid and severe, with local flooding in low spots as well as along rivers and streams. The Embarras River near Casey sustained record flows for the time of year for 3 days before subsiding (Figure 15, USGS). The White River in southwestern Indiana was above flood stage for 5 days in its middle reaches. In the cold air influx that followed, record lows were set on the 7th (St. Louis, MO), the 8th (Sioux City and Mason City, IA), and the 9th (St Cloud, MN, Springfield, IL, and Indianapolis, IN). Kansas City, MO, set new record lows on three consecutive days, October 7 to 9. Along with the cold air came the first strong lake effect snows in the snow belts of the northern Great Lakes region. Marquette, MI, received 12.1 inches of snow over several days from October 6th to 8th, Ironwood received 6 inches, and other locations received as much as 10 inches, especially in the highlands of the Upper Peninsula of Michigan.
On the evening of October 13th strong storms developed in southern Iowa, northern Missouri and western Illinois, prompting the issuance of severe thunderstorm warnings. A tornado produced minor damage near West Bend and Havelock in north-central Iowa. Some damage to trees and power lines was reported in northwest Missouri and in western Illinois wind gusts of 50 to 60 mph were recorded on the evening of the 13th.
During the warm latter part of October, an interesting weather phenomenon took place. The warmth on October 23rd was widespread and reaching near record levels throughout the Midwest. High temperatures averaged in the 70s in the central and southern Midwest and in the 60s in the northern Midwest. But the most interesting aspect of the conditions were the high levels of humidity in the air. This can partially be discerned by the huge area in which low temperatures on the 23rd were above 55 Deg F (Figure 16). Dense fog advisories were issued throughout the area on the mornings from October 22 to 24, especially in Minnesota, Iowa, Missouri, Wisconsin, Illinois, Michigan, and Indiana. Minneapolis set a record high low temperature of 58 Deg F on the 23rd. The widespread fog caused considerable delays at major airports in the region, including at Minneapolis, Chicago, Milwaukee, Indianapolis, and Detroit.