August 1-7, 2024

Temperature

Average temperatures were above normal for most of the region. Temperatures were 3-5°F above normal across the Ohio Valley, and 1-3°F above normal elsewhere (Figure 1). Only in northern Minnesota were average temperatures below normal, mainly by 1-2°F.

Minimum temperatures were similarly anomalous, with most of Ohio and Indiana 4-6°F above normal (Figure 2). Minimum temperatures averaged closer to normal heading west and north toward Minnesota, northern Wisconsin and the Great Plains. Sault Ste. Marie observed four consecutive days of minimum temperatures above 60°F August 1-4 for the first time in August since 2021. In Paducah, Kentucky, the 10-day period ending on August 3 was the longest stretch of minimum temperatures above 70°F in summer since 2020.

Average maximum temperatures were as much as 5°F below normal for the week across parts of Minnesota (Figure 3). Elsewhere, they were near normal through most of Wisconsin, central and eastern Michigan, and near the Quad Cities. Maximum temperatures were 3-5°F above normal through Indiana, Ohio and eastern Kentucky, as well as western Iowa and western Missouri. On August 5, the maximum temperature in Long Prairie, Minnesota was 63°F, which was both a record low high temperature for the day and the coldest August day since 2018.

Precipitation

Several lows and boundaries meandered through the Upper Midwest this week. Over 200 percent of normal precipitation was observed over much of Ohio, southern and central Michigan, Wisconsin, and southern and central Minnesota (Figure 4). Parts of Minnesota received 3-4 inches of precipitation for the week (Figure 5). Alexandria chandler Field in Alexandria, Minnesota observed 3.5 inches of precipitation on August 5 alone, which was the second wettest August day since records began in 1940. Findlay Airport in Findlay, Ohio observed its third wettest August day on record since 1942 with 2.90 inches of precipitation.

Drought erasure continued across the region into the beginning of August. D1 conditions (moderate drought) was removed from much of eastern Kentucky by August 6, as well as some of northeastern Ohio (Figure 6). Abnormally dry conditions were removed from a wide swath of western Missouri and western Indiana.

Severe Weather

With much of the precipitation came severe weather. There were 414 storm reports for the week, and 330 of them were wind reports (Figure 7). Most of these were associated with outbreaks in Kentucky and Ohio. There were also 26 tornado reports and 40 hail reports which were mostly located in Minnesota. On August 3, severe weather caused golf ball size hail near Long Prairie, Minnesota. An EF-1 tornado with 95 mph winds touched down for 5.4 miles on the northwest corner of Melrose, Minnesota. There was significant damage to homes and businesses before it crossed I-94, hit a golf course, and subsequently brought down over 200 trees . This was separate from another outbreak which spawned several EF-1 tornadoes in southern Minnesota on August 5. This system moved east, causing more tornadoes to touchdown in Ohio and Michigan and bringing straight-line winds of 80-90 mph to areas in and around Cleveland.