Below Normal Temperatures Dominate the Midwest

Below normal temperatures dominated the Midwest this week (Figure 1). Temperature deviations from northern Missouri to northern Minnesota were in excess of 10°F below normal, with the most extreme occurring in Minnesota (17-18°F below normal). Temperatures were 3-10°F below normal for the rest of the Midwest. Maximum temperatures were well below normal with widespread temperature departures in excess of 5°F (Figure 2). More extreme temperature departures were seen in Minnesota, where maximum temperatures were 15 to more than 20°F below normal. Minimum temperatures resembled the average temperature departure map for the week (Figure 3). There were 167 low minimum and 159 low maximum daily temperature records broken or tied across the Midwest this week (Figure 4).

Variable Precipitation throughout the Midwest

Precipitation was highly variable throughout the Midwest this week (Figure 5). The entire Midwest received at least 0.1 inches, with the heaviest rainfall in eastern Missouri, southeastern Iowa, western and southern Illinois, Kentucky, and eastern Ohio (0.75-2 inches). For many of these locations, amounts were 100-150 percent of normal precipitation (Figure 6). Isolated locations in eastern and southern Missouri and western Illinois were 150-200 percent of normal precipitation. Ralls County, Missouri, recorded 2.97 inches of precipitation, which was 2.01 inches above normal for the week. Their single day maximum precipitation total was 1.56 inches, which occurred on April 21st. To the north and to the east of this region, precipitation totals were less than 75 percent of normal. Western Missouri and western Iowa saw less than 10-50% of normal precipitation. Central to northern Minnesota saw in excess of 100 percent of normal precipitation, with isolated locations in the northwest receiving 175-300 percent of normal.

Say it ain’t Snow...

The southern-most extent of snow totals in excess of 0.1 inches extended from northern Missouri to the east through Illinois, southern Indiana, and southern Ohio (Figure 7). On the morning of April 18, western Iowa had 0.1 - 3 inches of snowfall on the ground (Figure 8). Cherokee County, Iowa, measured 3 inches exactly. Northern Illinois, southern Wisconsin, and central Indiana all had isolated locations with snowfall depths of 1 – 2 inches. Heaviest snowfall totals were measured in northern Minnesota, northern Wisconsin and Michigan’s Upper Peninsula (excess of 3 inches). Isolated locations in northern Minnesota received up to a foot of snow. There were 126 daily snowfall records broken or tied this week (Figure 9).

Drought Improvement in Northwestern Midwest

Overall, the percent land area in drought decreased slightly this week from 6.8 to 5.5 percent (Figure 10). Northern Minnesota saw improvement of the Moderate Drought (D1) to Abnormally Dry (D0). A small region in western Wisconsin was placed into the D1 category. The D1 in southern Minnesota/northern Iowa also decreased in size this week.

The Wind Continues

To say it has been windy, is an understatement. The National Weather Service in Des Moines Iowa, tweeted that there have been 39 wind advisories issued this year for their service area alone, which ties 2012 and trails 2014 with 41 wind advisories issued. On April 20, the St. Louis National Weather Service reported having 36 consecutive days where the winds had gusted to at least 20 miles per hour.