August 1-7, 2023
Western Great Lakes Warmth; Slightly Below Normal for Ohio Valley
Temperatures were very warm in a few parts of the region this week, with much of Minnesota and Wisconsin averaging anywhere from two to 2°F to 5°F above normal (Figure 1). Temperatures were, on average, 3.4°F above normal for the week in Minnesota. In Wisconsin, temperatures averaged 2.9°F above normal. Heading east, into Michigan, Indiana, Ohio and Kentucky, temperatures averaged anywhere between 1°F and 3°F below normal. The western side of the region also experienced very warm minimum temperatures, ending up 3°F to 5°F above normal stretching along a belt from Minnesota down to Missouri (Figure 2). Maximum temperatures were actually below normal from northern Missouri up along the Ohio River (Figure 3).
Heavy Rain for the mid-Missouri region; normal to below normal elsewhere
The heaviest rain fell across the Mississippi and Missouri River Valleys, with a band of 4 to 6 inches of rain stretching from southern Iowa down through much of Missouri (Figure 4). This was several inches above normal for that area (Figure 5). Much of Southern Iowa and Missouri saw over 500% of normal precipitation for the week (Figure 6). Meanwhile, most of Wisconsin averaged 5 to 10 percent of normal precipitation, while much of Ohio also stayed well below normal.
Minor Drought Changes
Overall, drought improvements were noticed across the Midwest for this first week of August (Figure 7). Little improvement was made in the Extreme Drought (D3) category, with south-central Wisconsin, including Madison, still in extreme drought. Moderate to severe drought (D1-D2) improved across the eastern Midwest, stretching from Michigan down through Indiana. Little to no improvements were made elsewhere.
A pattern change ushered in a quieter pattern for much of the first week of August. Storm reports were few and far between compared to prior weeks, with the majority of reports associated with a system that swept through the southern parts of the region (Figure 8). On August 2, hail stones up to 2.5 inches in diameter were reported in Jefferson City, Missouri. It was straight-line wind and tornado reports, however, that dominated the storm reports this week. In Knox County, Missouri, high winds displaced people from their homes and caused two injuries. The National Weather Service in Central Illinois confirmed an EF2 tornado with a path of over 25 miles went through Sangamon and Christian counties. There were no injuries, but at least one home was destroyed. On the same day, an EF1 tornado with a path of over 25 miles through southern Indiana was also confirmed by National Weather Service meteorologists in Louisville.