July 18-24, 2003
Midwest Weekly Highlights - July 18-24, 2003
Stormy weather adds to July rain totals.
Rainfall across the southeastern two-thirds of the Midwest was much above average this week, while much of Minnesota, Wisconsin, and northwestern Missouri remained high and dry (Figure 1). The clouds, rain, and cold frontal passages kept temperatures well below normal, as much as 6 degrees below normal in southeastern Iowa. The area of greatest departures correlated well with the area of rainfall this week (Figure 2). Only western Missouri and northwestern Minnesota experienced near to above normal temperatures.
It was another active week in the Midwest. Scattered thunderstorms that developed late on July 17 in northeastern Illinois developed into a mesoscale convective system (MCS) which drove south-southeastward during the early morning hours of July 18 (Figure 3). The thunderstorm complex brought more heavy rain to eastern Illinois and western Indiana, as well as producing damaging thunderstorm winds. Several tornado warnings were issued in the Chicago metropolitan area, and there were a number of reports of wind gusts of 50 to 60 mph. As the MCS moved south during the night additional storms began developing on its western flank. The line of storms moved to the south and west, reaching the Mississippi River by dawn. The thunderstorms continued to generate damaging winds as they marched to the south and west. Rainfall amounts were heavy, causing urban and flash flooding, especially in those areas that have already received heavy rainfall this month. The radar estimated rainfall from this event (Figure 4) depicts the areas that received the heaviest rain. There was significant and extensive hail damage to crops in Christian, Shelby, and Montgomery Counties in central Illinois (Figure 5).
Severe weather continued in Minnesota on July 19, while much of the central Midwest enjoyed slightly cooler and drier weather. Severe storms produced damaging winds and large hail, with numerous reports (Figure 6) of hail 1.00 to 1.75 inches, and one report from Cedar Mills, MN of 2.75 inch hail.
Warm and more humid air rapidly returned to much of the Midwest on July 20. The day began with thunderstorms ongoing over the upper Midwest in advance of a strong cold front. Thunderstorms began to develop during the late afternoon and evening from Iowa across southern Wisconsin, northern Illinois, and lower Michigan, and a number of severe thunderstorm and tornado watches were in effect for these areas. A line of storms progressed south during the overnight hours into central Illinois and Indiana, dropping more heavy rain and producing widespread wind damage (Figure 7). An F0 tornado touched down about 10 miles northeast of Logansport, IN during the predawn hours causing minor damage along a two mile path. Another weak tornado touched down on the south side of Lafayette, IN. Flash flood warnings were again issued for a number of eastern Illinois and northern and central Indiana counties. Roads and intersections in Fort Wayne, IN were closed as 6 to 12 inches of water covered many portions of the city after an estimated 2-3 inches of rain fell in a short period.
The storms continued on east during the day pounding much of Ohio. An F1 tornado touched down on the northeast side of Youngstown, OH during the afternoon. The tornado produced damage along an 8 mile path, downing numerous trees, knocking over a 2-story cinder clock building, and blowing a couple of railroad cars off of the tracks. Flash flooding was widespread, and a 10 year old boy drowned after venturing into a rain-swollen ditch. Two men drowned in Hudson, OH when floodwaters rushed through the basement of a condominium located between two small lakes. An estimated 5.50 inches of rain fell in a four hour period.
As a strong upper level trough rotated through the Midwest on July 21-22, showers and thunderstorms persisted behind the cold front moving through the region (Figure 8). A Canadian high pressure system built into the western and central Midwest, bringing unseasonably cool and dry weather to much of the region. Minimum temperatures on July 23 dropped into the upper 30s and low 40s over northeastern Minnesota and northwestern Wisconsin (Figure 9). Rain fell across southeastern Indiana, southern Ohio, and northern Kentucky through the morning hours of July 23. Scattered showers and thundershowers popped up over eastern Illinois and Indiana during the afternoon and, while showers and thunderstorms continued throughout the day into the evening in eastern Ohio, dropping another one to two inches of rain on already saturated ground. A flood watch continued into the morning of July 24 for much of eastern Ohio and adjacent portions of Pennsylvania and West Virginia.
On July 23rd the Henry County, IL Farm Service agency reported that 25,000 acres of crops in Henry County were damaged by severe weather, resulting in more than $10 million in losses. Illinois Governor Rod Blagojevich has declared 7 Illinois counties disaster areas as a result of the July storms.