Midwest Overview - October 2010
October was a relatively dry month in the Midwest
(Figure 1). Only northern Minnesota and small parts of northwest Wisconsin and northeast Ohio were above normal. In northern Minnesota, nearly all of the rain was associated with the big storm that moved through late in the month as the previous three weeks were well below normal. The rest of the region was below normal with Missouri (driest October since 1964), most of Iowa and Indiana, southern Illinois, and parts of Kentucky, Ohio, and Michigan receiving less than half their normal rainfall. The rain and snow in northeast Minnesota helped alleviate the drought but the dry conditions to the south have led to an expansion and worsening of the drought that has spread northward from the Ohio River Valley (Figure 2).
Temperatures averaged slightly above normal for October. Departures ranged from near normal in the south and east edges of the Midwest up to 5°F above normal in northern Minnesota (Figure 3). For most of the region, the maximum temperatures (Figure 4) were more above normal than the minimum temperatures (Figure 5). Iowa recorded its eighth straight warm month.
Despite the generally warm conditions there were surges of cooler weather that brought the first freeze to much of the region in October. The first surge of cold air came on the 3rd and 4th (Figure 6), bringing a freeze to much of Wisconsin and Michigan along with parts of Minnesota and Iowa. On the 22nd
(Figure 7), the core of cold air penetrated across Indiana bringing the first freeze to much of the region except Missouri and parts of Ohio and Kentucky. Most of Missouri picked up its first freeze on the morning of the 29th (Figure 8) as cold air pushed south on the back side of a big low pressure system.
Historic Storm on October 26th and 27th
A large low pressure system
(Figure 9) moved into the region and continued to deepen as it moved across Minnesota. Low pressure records were set for both Minnesota and Wisconsin and the storm ranked among the lowest in history for an extratropical system over the continental United States. The system brought most of the month's severe weather on the 25th and 26th (Figure 10). Severe weather broke out from southwest Missouri to southeast Wisconsin and moved quickly to the east along the cold front that extended from the low all the way to the Gulf of Mexico. Hundreds of wind reports and dozens of tornadoes were observed. Two injuries were reported with the EF1 tornado in southeast Wisconsin
(Racine and Kenosha counties). In South Bend, Indiana
(St. Joseph County), a Notre Dame student died filming football practice when the lift holding him approximately 50 feet in the air was blown over onto a parking lot. Winds knocked out power to hundreds of thousands across the Midwest.
Farmers took advantage of the many days of ideal field conditions to wrap up harvest early. It was a welcome change from last year's late harvest. This year the crops reached maturity earlier than normal and then the harvest weather cooperated allowing for a rapid and early harvest. Because most of the crop were already harvested, the high winds late in the month did not affect harvest significantly.