Midwest Overview - May 2009
Precipitation varied from below 50% of normal in northwest Iowa, central Minnesota, and northwest Wisconsin to nearly 200% of normal in eastern Kentucky and south of the confluence of the Mississippi and Ohio Rivers (Figure 1). Northwest Minnesota was also well above normal for the month. Dry conditions persisted across southern Minnesota, northwest Wisconsin, and upper Michigan in May extending the drought in those areas.
Temperatures were cool, as much as 5°F to 8°F below normal, in northwest Minnesota (Figure 2). Across the rest of the region, temperatures were within 2°F of normal. A significant cold snap on May 17 and 18 brought record cold temperatures to the southern two-thirds of the region. Strong southerly winds combined with dry conditions led to a rapid warming in Minnesota, Wisconsin, and Michigan just days later. Record warmth spread across the three states on May 19-21 with monthly records at Gaylord, Minnesota (97°F May 20) and Big Bay, Michigan (94°F May 21).
Across the nation, May had less severe weather than normal especially in the latter half of the month. However, there were fatalities in the Midwest due to tornadoes, severe thunderstorms, and flooding during the month. On May 8, tornadoes killed in two in Kentucky (Madison County) and one in Missouri (Dallas County). Two additional fatalities were associated with severe thunderstorms in Missouri (Butler County) on May 8. May 13 brought deadly tornadoes to Missouri's Sullivan County (1 death) and Adair County (2 deaths). Flooding the night of May 16 along the Spoon River in Illinois (Knox County and Fulton County) washed two cars into the river, killing the driver in each case.
Temperatures for March, April, and May were near normal across most of the Midwest. Only northwest Minnesota, 2°F to 5°F cooler than normal, varied more than 2°F from normal (Figure 3). Rainfall in the spring was below normal in northwest Iowa, southern Minnesota, and northwest Wisconsin. Above normal precipitation fell over much of the region with a wide swath exceeding 125% of normal from Kansas City, Missouri northeast to Detroit, Michigan (Figure 4). Northwest Minnesota and southern Kentucky were also above normal for the season. Northwest Illinois was wettest at about 175% of normal.
A wet April followed by a wet May across the central Midwest led to significant planting delays across much of the Midwest. At the beginning of May only Minnesota and Iowa were ahead of schedule, with the remaining states significantly behind. As of May 3 only five percent of the corn was planted both in Illinois and Indiana, compared to a five-year average of 66 percent and 47 percent, respectively. Conditions improved and planting increased about the middle of the month, with the biggest surge during the week ending May 24. This was a sunny, dry, and warm week, and corn planting jumped to 62 percent complete in Illinois and 55 percent complete in Indiana. By the end of the month planting was complete in Iowa, and 90 percent to complete in Minnesota, Wisconsin, Ohio, and Missouri. Corn planting was 89 percent complete in Kentucky, 82 percent complete in Illinois, and 78 percent complete in Indiana. Some of the remaining corn acreage may be planted in soybeans due to the lateness of the season. Soybean planting, which typically starts later than corn, was also well behind schedule except in Iowa, Minnesota, Wisconsin, and Ohio.
Flooding along the Red River in western Minnesota and the Illinois River in west central Illinois were big stories this spring. The Red River at Fargo, ND set records for both peak flood stage (40.82 feet on Mar 28) and consecutive days above flood (62), moderate flood (37), and major flood stage (31). Grand Forks, ND also set a record with 32 consecutive days above moderate flood stage. Along the Illinois River, Peoria broke its record for days above flood stage with 86 days and counting as of May 31.