Midwest Weekly Highlights - July 18-24, 2012
Precipitation Amounts Varied
A few storm systems made their way across parts of the Midwest during the week, bringing a couple inches of precipitation with it. Southern Minnesota, the southern Lake Michigan region, parts of Ohio, and eastern Kentucky received at least 1.5" of rainfall throughout the week (Figure 1). The highest amounts were central Minnesota, where 2.5" to 3" of precipitation was received. Part of the southern Lake Michigan region and south central Kentucky received over 2" of rainfall.
Away from this fairly heavy band of precipitation, rainfall was minimal throughout the week. Parts of northern Minnesota, Iowa, and Missouri received no precipitation, while the rest of the region only received 0.01" to 0.5". As a result, precipitation was below normal across much of the region (Figure 2). However, the region that received at least 1.5" of rainfall throughout the week received 125% to 300% of their normal precipitation for this time of year. Several daily precipitation records were set throughout the week.
Above Average Temperatures and Record Highs Persist
Average daily temperatures remained unseasonably warm across much of the Midwest during the past week. The highest departures of 7°F to 10°F above average were in the western Midwest, in Minnesota, Iowa, Missouri, and western Illinois (Figure 3). Parts of Michigan, Ohio, and Kentucky experienced temperatures that were closer to normal.
Maximum temperatures were significantly above normal in the western Midwest (Figure 4). Southern Iowa and northern Missouri experienced maximum temperatures that were 12°F to 13°F above normal. Eastern Kentucky and southern Ohio actually saw maximum temperatures that were a few degrees below normal.
Over 100 daily temperature records were set on each of four days, the 18th and 19th and also the 23rd and 24th
(Figure 5). There was a slight cool down in the middle of the week, where temperatures were closer to normal for much of the region and not as many record highs were set (Figure 6). During this time, there were some record minimum temperatures set as well.
Widespread Midwest Drought
The severe drought in the Midwest continued to expand this week, with the latest US Drought Monitor showing an increase in all categories of drought (Figure 7). Exceptional drought (D4), the highest level of drought, expanded to 4.33% of the region compared to the 0.84% last week. Last week, D4 drought was mainly constrained to Kentucky but this week it expanded to the Missouri Bootheel, southern Illinois, and western Indiana. Just over 28% of the region is now experiencing severe drought (D3), which is a 17% increase from last week. Unfortunately, precipitation this week was minimal in the areas experiencing the most intense drought conditions. While some areas did receive a little precipitation, it wasn't enough to reduce the severity of the drought on the latest release of the US Drought Monitor.
The impacts of the drought continue to be felt, especially in agriculture. The condition of corn continued to deteriorate across the region, especially in the most drought-stricken states of Illinois, Missouri, Kentucky, and Indiana (Figure 8).
There were two storm systems, both associated with high wind and hail, that moved through parts of the region this week, one at the beginning of the week (the 18th and 19th) and one at the end (the 23rd and 24th) (Figure 9). Both systems brought winds measuring up to 80 mph to the Chicago and northern Indiana regions. The highest wind report of 85 mph was associated with the derecho on the 24th in Brems, Indiana (Starke County). The Chicago region had several reports of winds 70 to 80 mph on the 23rd and 24th. As a result of the high winds associated with these storms, there were several power outages reported and large trees and power lines blown down.