Midwest Overview - May 1-7, 2003

Tornadoes ruled the first week of May.

The first week of the month was dominated by a weather pattern very favorable for severe weather over the Midwest.  A sign of things to come came on May 1 when severe thunderstorms developed ahead of a cold front in Indiana, Ohio, and Kentucky.  Two tornadoes touched down in Indiana, one near Union City and the other near Muncie.

A major outbreak of severe weather hit the Midwest and Ohio Valley on Sunday, May 4 as a storm system intensified over the Central Plains. Preliminary reports from the Storm Prediction Center (Figure 1) indicate there were 94 tornadoes, 115 reports of wind damage, and 309 reports of large hail.  Missouri was the hardest hit with 18 fatalities.

On May 5 the focus of the severe weather had mostly shifted east into Kentucky and Tennessee and south into the northern Gulf states. One unconfirmed tornado was reported near Science Hill, KY.  Further to the north, thunderstorms broke out ahead of the cold front moving through the Midwest, and severe storms were reported in Michigan. A tornado touched down near Addison, MI, about 20 miles SSE of Jackson, tearing a roof off of a house.  By evening severe storms had again erupted over Missouri, and tornadoes were reported in southwest Missouri near Bakersfield and Gainesville.

Widespread severe weather returned to Missouri, southern Illinois, and northern Kentucky on Tuesday, May 6.  The front that had moved south on Monday began to return northward as a warm front.  By late afternoon severe thunderstorm and tornado watches covered the southern half of Missouri, southern Illinois, and southern Indiana.  Preliminary storm reports counted 50 tornadoes, 151 reports of wind damage, and 249 reports of large hail (Figure 2).  Tornadoes were reported in western Massac County, and Pulaski, Pope, and Alexander counties in southern Illinois. The tornadoes left two people dead in Massac and Pulaski Counties. In Missouri, a supercell storm (Figure 3) spawned a tornado that flattened the roof of a junior high school in the town of De Soto in Jefferson County, southwest of St. Louis. A nursing home was also damage, but the residents escaped unharmed. Only a few minor injuries were reported in the De Soto area.

Severe thunderstorms developed again on May 7 in the Midwest, but on a much more limited basis. A weak wave of low pressure moving through Illinois and Indiana during the day triggered scattered severe thunderstorms in east-central Illinois, northern Indiana, southern Michigan, and northern Ohio. A small tornado touched down in a field for a few seconds east of Bloomington, IL, causing no damage.  One and three quarter inch hail was reported near Elkhart, IN. Trees and power lines were brought down by high winds in north central Ohio.

Rainfall early in the period brought substantial relief to the dry conditions in eastern Iowa, northern Illinois, and southern Wisconsin.  Precipitation for the first week of May was well above normal across almost the entire Midwest, with the most notable exception and area from far northeastern Minnesota, to northern Wisconsin, and the Michigan Upper Peninsula (Figure 4).  The wet weather put the brakes on spring planting in some areas, but all Midwestern states are making normal to well above normal progress in corn planting as of May 4. Soybean planting is running near to behind normal, except in Ohio, where 41 percent of the soybean acreage was planted, well ahead of the 5-year average of 15 percent.

The pattern of temperatures departures this period reflected the mean position of the frontal oscillating across the Midwest.  Average temperatures ranged from 4F below normal in central Wisconsin to 5F above normal along the Ohio River (Figure 5).