Midwest Weekly Highlights - August 1-7, 2012
The first week of August brought an inch or two of precipitation to many parts of the Midwest, while other regions received less
(Figure 1). The greatest precipitation amounts were in Kentucky, where over 1.5" of rain fell across much of the state. Parts of southern Kentucky even received 2.5" to 3" of precipitation. Unfortunately, much of the significant rainfall missed western Kentucky, which is where the drought is most severe. In contrast to much of Kentucky, precipitation during the first week of August was minimal in northern Missouri, where only 0.01" to 0.2" was received throughout the week. Overall, precipitation was near- to below-normal for much of the region (Figure 2). Parts of Kentucky, Illinois, and Ohio received at least an inch above normal precipitation throughout the week. Northern Missouri was 0.75" to 1" below normal. There were several daily precipitation records set throughout the week, with the majority occurring on August 5th.
Above Average Temperatures Continue
While average temperatures were above normal across a majority of the Midwest, much of the region was only above average by a degree or two and some locations experienced near-normal temperatures (Figure 3). Missouri continued to experience the greatest departures from normal, with the southwest part of the state seeing departures of 6°F to 8°F above normal. Much of Minnesota, northern Wisconsin, and part of Iowa experienced temperatures that were near-normal for the first week of August.
Maximum temperatures ranged from 100°F to 105°F in southwest Missouri to 75°F to 80°F in the northern Midwest (Figure 4). Overall, maximum temperatures were above average across much of the region, except for northern Minnesota and eastern Kentucky, where maximum temperatures were either near- or below-normal
(Figure 5). The highest departures of 10°F to 12°F above normal were in southwest Missouri. In contrast, minimum temperatures were near- to below-normal for much of the central Midwest (Figure 6). In eastern Iowa, minimum temperatures were anywhere from 1°F to 4°F below normal. Minimum temperatures were above average in parts of the northern Midwest and across the southern Midwest. There were a number of daily temperature records set throughout the week, including both record high and record low temperatures.
There were no major changes from last week on the latest release of the US Drought Monitor
(Figure 7). The biggest differences are found in Iowa and Missouri. Much of central Iowa was upgraded to an extreme drought (D3) and parts of western and southern Missouri were upgraded to the highest level of drought, exceptional drought (D4). As a result of the expansion into western Missouri, exceptional drought is now impacting 5.78% of the Midwest. To read more about the conditions in a region experiencing exceptional drought, please see the August 8th edition of The Climate Observer to read an interview with Rankin Powell, a County Extension Agent in Union County, Kentucky.
Severe weather was reported in all nine Midwest states and on all but one day during the first week of August (Figure 8). One of the worst events during the week occurred on August 4th, when a strong derecho made its way across northern Illinois, Indiana, and Ohio (Figure 9). Throughout the Midwest that day, there were 181 preliminary high wind reports, the highest of which being a few reports of 80 mph in Tinley Park and Hometown, Illinois (Cook County) and Fulton, Illinois (Whiteside County). As this strong derecho made its way through the Chicago region, it endangered tens of thousands at Chicago's annual music festival, Lollapalooza. Luckily, the festival was suspended for a few hours and attendees safely took shelter in parking garages. There was also one tornado reported in Rolling Prairie, Indiana (La Porte County) and a few large hail reports as well.