May 8-14, 2024

Temperature

Average temperatures were above the normal for much of the region (Figure 1). Most of Minnesota was 4°F above normal, with areas up to 5-6°F above normal. All of Wisconsin, Iowa, Illinois, and Indiana were at least 1°F above normal, with more than half of Missouri, Michigan, Ohio, and Kentucky following suit. Southeastern Kentucky and a small pocket in the UP of Michigan came in averaging 1°F below normal. Illinois, Indiana, and Iowa, all came in averaging 2.7°F above the normal, which was the highest departure in the area by state. Wisconsin was close behind, averaging 2.6°F above normal. Michigan averaged 0.6°F above normal, which was the lowest departure.

Minimum temperatures were also above normal for most of the region (Figure 2). Everywhere but southeastern Kentucky, east-central Michigan, northern Wisconsin into the western UP of Michigan, northeastern Minnesota, and parts of southeastern Iowa and Missouri were at least 1°F above normal. A few pockets in eastern Iowa and near the bootheel of Missouri reached an average of 4°F above normal.

Average maximum temperatures made a northwest-to-southeast gradient across the region during the week (Figure 3). The warmest averages were seen across Minnesota and into western Wisconsin. The lower Mississippi and Ohio Valleys came in close to the average for the week. The central UP of Michigan and southeastern Kentucky were the coolest average areas in the region, by as much as 3°F below normal. May 12th was a particularly warm day for the northwestern Midwest, with much of Minnesota, Wisconsin, and Iowa running 15-20°F above normal that day.

Precipitation

Precipitation was primarily located east of the Mississippi this week (Figure 4). Southern Kentucky and areas around Chicago received the highest percentages of rainfall. A COOP station in Russellville, Kentucky, which has 78 years of data, recorded 4.07 inches of rainfall this past week. That is 73% of their monthly average of 5.52 inches. Conversely, southern Minnesota and portions of Missouri were the farthest behind the normal. Rochester International Airport, a COOP station in southeastern Minnesota with data from the past 111 years, recorded no measurable precipitation this week. This was the first time since 1977 and 8th time ever that this particular station had received no measurable precipitation on this week of the year.

Drought conditions continued to improve for the areas in the region that were still experiencing one (Figure 5). D0 (abnormally dry) conditions dropped from 26 percent to 20.5 percent. Areas in a D1 (moderate drought) also decreased from 10 percent to 7.6 percent. Areas under a D2 (severe drought) did not change much from the previous week, decreasing less than a half of a percent of the total region’s area. This is the first time since April of 2023 that the region has had less than 21% of the area in a D0 drought.

Severe Weather

There were 404 storm reports across the region this past week (Figure 6). Over 200 of them were for hail, 134 were for wind, and 29 were for tornado reports.

A majority of the reports came from Missouri, Illinois, Indiana, and Kentucky on May 8th. Among the most notable were multiple reports of baseball sized hail, one of which occurred just south of Grubville, Missouri.

As the storms moved east, wind became a bigger threat as well. An EF-1 tornado impacted the community of Cora, Illinois, injuring one. A swath of straight-line winds went through Rinard, Illinois, preliminarily measuring 75-85 mph. Flash flooding and accumulating hail became a concern, particularly in the Royalton, Illinois area.