Midwest Weekly Highlights - May 18-24, 2008
Cold and Quiet Week
Most of the Midwest endured another week of much cooler than normal weather as a persistent trough of low pressure aloft directed cold air out of Canada and into the northeastern quarter of the country (Figure 1). Average daily temperatures were 8°F to 10°F below normal from Illinois and Wisconsin eastward (Figure 2). Only extreme southwestern Missouri experienced temperatures that were near to above normal.
Most of the region was dry this week, with less than 50 percent of normal weekly precipitation (Figure 3). The exception was western Iowa south through western Missouri, where thunderstorms produced above normal rainfall this week. A band of near normal rainfall also occurred across north-central Illinois, and normal to above normal rainfall occurred from southeastern Indiana through southern Ohio and northern Kentucky. This rainfall was the result of a low pressure wave moving along a front in the Ohio Valley on May 20. Most of the rain in western Missouri and Iowa occurred the last three days of the period as thunderstorms erupted ahead of a deepening low pressure system over the central Rockies (Figure 4). A few severe storms were reported in Iowa and Missouri during this period.
A small area of Moderate Drought was depicted in northwestern Minnesota on the May 20 U.S. Drought Monitor as a result of recent weeks of dry weather (Figure 5).
Planting Accelerates with Dry Weather
Corn and soybean planting progress accelerated this week with dry weather across most of the region, but as of the May 19 Crop Progress reports, it is still behind the 5-year average in all Midwestern states except for Michigan (Figure 6, Figure 7). Michigan corn planting is running about 15 percent ahead of the 5-year average. The biggest gains in corn planting since last week occurred in Iowa and Minnesota, where corn planting jumped 32 and 35 percent, respectively. Soybean planting ranges from 41 percent behind the 5-year average in Ohio to 12 percent ahead of the average in Michigan.