Heavy Precipitation Across the South
The southern portions of the region received precipitation that was 150% to over 600% of normal throughout the second week of August (Figure 1). Elsewhere, below normal precipitation was widespread across the region, with the exception of southern Michigan, southern Minnesota, and northwest Iowa, where precipitation was 200% to 600% of normal. The rain in the southern portions of the region ranged from 3" to 8" throughout the week, with the highest totals falling in southeastern Missouri and Kentucky (Figure 2). Heavy precipitation in this region fell for almost a week straight, causing damaging flash floods in this region (see "Flash Floods" section below for more details). There were several daily precipitation records set throughout the week, a few of which were also monthly precipitation records.
Moderate drought expanded across the Midwest during the second week of August
(Figure 3). The expansion mainly occurred in Iowa and as a result, just over 6% of the region is now experiencing moderate drought conditions (D1). Other areas affected by moderate drought are northern Missouri and northern Minnesota. In terms of the status of drought in other Midwest states, Illinois and Wisconsin have portions that are listed as abnormally dry, while Michigan, Ohio, Indiana, and Kentucky have no dry conditions depicted on the US Drought Monitor.
Widespread Below Normal Temperatures
Below normal temperatures were widespread across much of the Midwest during the second week of August (Figure 4). The greatest departures of 8°F to 10°F below normal were found in northern Minnesota, northern Wisconsin, and northern Michigan. Some portions of the region did in fact experience near normal temperatures, including southeast Indiana, most of Kentucky, and southern Ohio.
The below normal temperatures brought in the first 32°F freeze reports to the region
(Figure 5). The first reports of freezing temperatures came from Tower, MN (St. Louis County) on the 10th (32°F), Embarass, MN (St. Louis County) on the 14th (31°F), and Stambaugh, MI (Iron County) on the 14th (32°F). There were some daily temperature records set throughout the week, mainly record lows, with a few scattered record highs in Ohio and Kentucky.
Flash Floods in Missouri and Kentucky
A stationary front positioned over the southern Midwest brought immense amounts of precipitation to Missouri and Kentucky during the second week of August (Figure 6). Missouri had already been dealing with flash floods from this same system during the first week of August. In southern Missouri, heavy rainfall occurred every night from August 3rd to 10th (Figure 7). Within these nightly storms, rainfall rates of two inches per hour trained across the same location for several hours. According to the National Weather Service report from the Springfield, MO office, there was a decent area of greater than 15 inches from the southern half of Pulaski County south to Wright County. In the southern Missouri area, flash flood event impacts include multiple evacuations of mobile home parks and even towns, flood-related fatalities, several county road closures as well as interstate closures, and numerous houses and other buildings flooded. To read more and see pictures, visit the National Weather Service report.
In Kentucky, the greatest weekly rainfall totals were over 6", with a highest reported total of 8.14" in Warren County, with nearly 8" also reported in Logan, Taylor, Boyle, and Anderson counties (Figure 8). The heavy rains resulted in flash floods, which caused school closures, building and house flooding, and a mudslide in Grethel, KY (Floyd County). Luckily, no flood-related fatalities have been reported in Kentucky yet. For other detailed maps of storm totals, visit the NWS Louisville, KY and NWS Jackson, KY summaries.
Growing Season Update
Crop growth in the Midwest is being slowed by the current cool temperatures, as much of the region is below normal growing degree day accumulation for this time of year (Figure 9). Compared to the 5-year average, the percent of corn in the dough and dent stages are behind average in all nine Midwest states (Figure 10). As of August 11th, a majority of the corn crop in the Midwest is in good or excellent (Figure 11). Compared to the 5-year average, the percent of soybeans blooming or setting pods is slightly behind average, especially in Iowa and Wisconsin in terms of setting pods (Figure 12). Similar to corn crop, a majority of the soybean crop is also in good to excellent condition across the Midwest (Figure 13).
With the current delay in crop development due to cooler weather and the planting delay this past spring because of wet weather, there is a growing concern in the farming community in the Midwest that the crops will not be ready to go by the first frost this fall. To track the first fall freeze across the region, visit the Freeze Maps on the Midwest Climate Watch.