Midwest Weekly Highlights - October 1-10, 2011

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Month Off to a Dry Start

Very little rain fell in the first ten days of the month (Figure 1). The entire region was below normal, with percentage of normal ranging from 0% in the central Midwest to just over 75% of normal in northeast Ohio and parts of Minnesota (Figure 2). The dry conditions, along with warm and windy conditions, led to an increase in both Moderate and Severe Drought across the Midwest as shown on the October 4th US Drought Monitor (Figure 3). Additional days of dry weather in the period followed, so improvements were not expected on the next update.
 

Big Warm Up

On the heels of the cutoff low that dominated the weather in late September, nighttime temperatures were well below normal for most of the Midwest. Minimum temperatures averaged more than 10°F below normal from Iowa to Kentucky and Missouri to southwest Michigan (Figure 4). Some areas in the central Midwest (Figure 5) picked up their first freeze (32°F) and parts of the upper Midwest (Figure 6) experienced their first hard freeze (28°F) early in the month.

High pressure moved in to dominate the weather for the remainder of the period bringing much warmer temperatures (Figure 7). Maximum temperatures were well above average especially in the upper Midwest. Departures ranged from about 6°F in the south to more than 20°F above normal in northern Wisconsin and the Upper Peninsula of Michigan (Figure 8).

Temperatures for the period averaged above normal for most of the Midwest (Figure 9). Kentucky was slightly below normal and along the Ohio River temperatures were close to normal. Moving further to the northwest, temperatures warmed to as much as 15°F to 17°F above normal in northwest Minnesota. Daily temperature records reflected the warm-up with record lows the first three days of October followed by over 200 record highs later in the period.
 

Missouri River Flood Impacts

After being closed for about four months, Interstate 29 in western Iowa and northwest Missouri finally was finally reopened. Traffic was still slowed in stretches of the highway for continued roadway repairs. Similarly, the Missouri River was also opened for traffic despite waters remaining quite high. River traffic had also been restricted or closed since June.
 

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