Mix of Above and Below Normal Precipitation
Significant precipitation measuring 3" to 5" in some places fell across portions of Iowa, southern Wisconsin, and northern Michigan during the second week of April (Figure 1). Much of this precipitation fell late in the week as a storm system moved its way across the Midwest (Figure 2), with a majority falling on April 12th and 13th (Figure 3). There was some snowfall associated with this event as well, with 2" to 8" falling in portions of Iowa, Wisconsin, and Upper Michigan (Figure 4). The rainfall totals in Iowa, Wisconsin, and Michigan were 300% to 750% of normal (Figure 5) and snowfall totals in Wisconsin and Upper Michigan were 3" to 5" above normal for the second week in April (Figure 6).
Precipitation was below normal in many areas of the region, including only 5% to 25% of normal in portions of Minnesota and eastern Kentucky
(Figure 5). Drought remains present in the Midwest, but to a minimal extent
(Figure 7). Overall, only 10% of the region is experiencing drought, with an additional 18% classified as abnormally dry. The highest level of drought in the Midwest as of April 15th is severe drought (D2), which is found in Iowa. Moderate drought (D1) remains in southern Minnesota, western Iowa, and portions of western Missouri.
Unseasonably Warm Temperatures
The Midwest region, with the exception of portions of the Upper Midwest, experienced above normal temperatures during the second week of April (Figure 8). The largest departures of 9°F to 11°F above normal were in the western Lake Erie basin. Northern Minnesota and Wisconsin experienced temperatures that were -1°F to -5°F below normal. The departures from normal temperatures were greater for maximum temperature
(Figure 9) than minimum temperature (Figure 10). April 12th was the warmest day of the week, with temperatures of 75°F to 80°F as far north as northern Illinois and Iowa
Severe Weather and Flash Flooding
In addition to heavy rainfall, the slow-moving storm system on April 12th and 13th also brought severe weather to portions of the upper Midwest and Missouri (Figure 12). A majority of the reports were for large hail in Iowa, Wisconsin, northern Illinois, and Michigan, but there were also a number of high wind reports and a few tornado reports in Iowa (Washington, Johnson, and Cedar counties). In Michigan, significant damage resulted from straight line winds, which gusted to 75mph to 85 mph. A report from Grand Rapids NWS summarizes the damage in their county warning area during this event. The heavy rainfall in Wisconsin caused urban flooding in Oshkosh, WI (Winnebago County) and several roads were closed due to high water. Other locations in Wisconsin and Michigan saw lowland flooding as well as a rise in area creeks and rivers. The Grand Rapids NWS office provided some aerial photography of the ongoing flooding in this area.