Midwest Weekly Highlights - April 1-7, 2012

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Cooler Temperatures as Week Progressed

Above average temperatures continued across the Midwest during the first week of April (Figure 1). Western Iowa and southern Minnesota experienced the highest departures of 13°F to 16°F above average temperatures, while northeast Ohio experienced near normal to just below normal temperatures.

The week started out very warm, but temperatures progressively got cooler throughout the week. On the first two days of the month, western parts of the region experienced average temperatures that were at least 17°F above normal. In western Iowa, maximum temperatures reached 90°F to 93°F on April 1st, which are 26°F to 27°F above average for this region (Figure 2). Even though temperatures cooled down over the last five days of week, temperatures remained above average for most of the region (Figure 3). Freezing overnight temperatures spread south on April 5th and 6th, bringing 25°F to 30°F temperatures to parts of the region that have not experienced such temperatures for a few weeks (Figure 4). There were over 600 daily temperature records set during the first 5 days of the month, including 2 monthly records in Pana, Illinois (Christian County) and Sikeston, Missouri (Scott County) on April 3.

Precipitation Below Normal for a Majority of the Region

Rainfall totals during the first week of April ranged from no precipitation in parts of the northern Midwest to just over 1.5 inches in Kentucky (Figure 5). Heavy rainfall events on April 1st, 3rd, and 4th, which caused some flash flooding issues in Kentucky, produced the high rainfall totals of an inch or more in Kentucky and southern Illinois. Most of the Midwest experienced below average preciptiation during the week, except for parts of southern Illinois and eastern Kentucky, where 100% to 175% of precipition was received (Figure 6). There was no snow reported during the week, which for the northern Midwest is below normal by at least 0.5 inches and 3 to 3.5 inches below normal in northern Wisconsin and Upper Michigan (Figure 7). During the first week of April, there were just over 50 daily precipitation records set.

The U.S. Drought Monitor for April 3rd depicts continuing Moderate to Severe Drought conditions in Minnesota and Iowa and developing abnormally dry conditions across central Illinois and western Kentucky (Figure 8).  

Severe Weather

Severe weather was reported in six of the nine Midwest states during the week (Figure 9). Severe thunderstorms that moved through the Midwest on the early morning of April 1st produced several hail reports in Indiana, Ohio, and Kentucky. Reports indicated that hail ranged from 1 inch to 2 inches. The largest hail of 2 inches was reported in Lawrence, Indiana (Marion County). On April 3rd, severe weather ripped through the southern United States, but only the northern end of the storms impacted the Midwest. Severe storms moved through Kentucky on April 3rd and high winds were reported, which knocked down power lines and trees. These storms also produced flash flooding issues in parts of Kentucky. There were two tornadoes reported on April 5th in Hayti, Missouri (Pemiscot County) and Marston, Missouri (New Madrid County). The tornado report in Hayti was spotted by several sources and the Marston tornado was reported by the public but remains unconfirmed.

-MW-