Above-Normal Temperatures

Temperatures were near-to-above normal in most of the Midwest this week. However, Indiana, Kentucky, and Ohio experienced slightly below-normal temperatures (Figure 1). Preliminary statewide data indicated that Wisconsin, Missouri, and Minnesota were the most abnormal with temperatures that were 3.5°F, 3.1°F, and 2.8°F above normal, respectively. The temperature in Theilman, Minnesota (Wabasha County) was 76.8°F, which was 6.2°F above normal for the week. The highest maximum temperature at this station was 97°F, which occurred on June 30. Corners, Kentucky (Breckinridge County) had a temperature of 67.5°F, which was exactly 6.5°F below normal for the week. The lowest minimum temperature recorded at this station was 47°F on June 23. The heat index became a problem mid-week. NWS Paducah Kentucky reported that heat index values ranged from 103 to 114°F across the Ohio River Valley on June 25. Above-normal maximum temperatures (Figure 2) consumed Wisconsin, Minnesota, parts of Michigan, Iowa, and Illinois; but were the highest in central Missouri (6-8°F above normal). Minimum temperatures (Figure 3) were above normal in the northern and eastern Midwest and near normal everywhere else. There were 34 daily high maximum and 26 high minimum temperature records that were broken or tied this week (Figure 4). There were also 5 daily low minimum and 33 low maximum records that were broken or tied (Figure 5).

Normal Precipitation Across Midwest

Most of the Midwest received more than an inch of rain this week. However, central and southern Missouri recorded less than 0.3 inches of rain, worsening drought conditions. The heaviest rain totals were observed in Kentucky where many of the stations measured 1.5 to over 4 inches (Figure 6), which was 1 to 2.5 inches above normal (Figure 7) or over 200 percent of normal for the week (Figure 8). Lexington, Kentucky (Fayette County) measured 4.27 inches of rain, which was 2.84 inches above normal. On June 30, 2.57 inches of precipitation was measured at this location. However, Kentucky was not the only place that experienced above-normal precipitation. Lake County, Minnesota also measured 4.27 inches of rain, which was 2.96 inches above normal for the week. Overall, there were 64 total daily precipitation records broken or tied this week (Figure 9).

Severe Storms and Derecho Impact Central Midwest

There were 37-tornado, 305-hail, 847-wind, and 58-high wind preliminary storm reports this week (Figure 10). There were over 30 tornado reports between June 24 and 25, spanning across Minnesota, Iowa, Indiana, and Kentucky. The NWS Indianapolis survey reported that an EF-2 tornado with a maximum wind speed of 115 mph, a path length of 5.4 miles, and a maximum width up to 400 yards began near Bargersville, Indiana (Johnson County) on June 25. Another EF-2 tornado hit Martin and Dubois Counties in Indiana tragically resulting in one casualty and an injury. A derecho brought significant hail, damaging winds, and tornadoes to the central Midwest on June 29. There were 467 reports of wind damage stretching from Iowa, Missouri, Illinois, Indiana, and Kentucky. Preliminary storm reports indicated 13 instances of 100 mph winds in Iowa, Illinois, and Missouri. There were several reports of damage to vehicles, houses, other structures, and fallen trees. Many locations went without power for more than 24 hours.

U.S. Drought Monitor Update

The June 27 U.S. Drought Monitor had a nearly 9 percent increase in Midwest land in at least a Severe Drought (D2) category (Figure 11). Extreme Drought (D3) expanded in Missouri and western Illinois as a result of the continued lack of rain. Further expansion of D2 occurred in Iowa, Illinois, Indiana and Michigan. Some improvement was introduced to eastern Indiana, Ohio, and Kentucky as a result of recent rains.

Poor Air Quality

Canadian wildfires continued to impact the air quality of the U.S. this week, especially in the Midwest, resulting in widespread air quality alerts. The U.S. Air Quality Index exceeded 101 in Midwest locations nearly every day this week, which impacted sensitive groups. Towards the end of the week, the Air Quality Index even exceeded 201, increasing the risk of health effects for everyone, in various Midwest locations. Smoke was visible and could smell it at times (Figure 12). Meteorologist, Blake Harms, tweeted that the air quality in Grand Rapids, Michigan was 217, which was firmly in the “very unhealthy” quality on June 27.