April 8-14, 2012
Midwest Weekly Highlights - April 8-14, 2012
Mix of Above and Below Average Temperatures in the Midwest
Temperatures across the Midwest during the second week of April ranged from 30°F to 35°F in northern Minnesota to 55°F to 60°F in southern Missouri (Figure 1). Unlike the last few weeks, average temperatures were near to below normal across a significant portion of the Midwest (Figure 2). Below normal temperatures were found in Kentucky, Ohio, southern Indiana, and southern Illinois, with the largest departures of -5°F to -6°F in northern Minnesota and east central Kentucky. Despite the more seasonal temperatures, some parts of the Midwest continued to experience above average temperatures. Average temperatures were at least 1°F above average in Wisconsin, Michigan, northern Illinois, western Missouri and Iowa, and parts of Minnesota. The largest departures of +6°F to +7°F were found in Upper Michigan.
Minimum temperatures (Figure 3) were unseasonably cool for much of the region, which is in contrast to the above average maximum temperatures found across a significant portion of the Midwest (Figure 4). Overall, there were just a handful of daily temperature records set during the week, including record highs and record lows.
Abundant Precipitation in Missouri and Southern Iowa
Precipitation was abundant in Missouri during the second week of April, with over an inch of rain falling across a large portion of the state and over 2.5 inches in central Missouri (Figure 5). The rainfall in Missouri produced precipitation totals that were 125% to 300% above average (Figure 6). Precipitation totals were lower in other parts of the Midwest, resulting in below average precipitation across a majority of the region. The lowest precipitation totals were in eastern Kentucky, where no precipitation was received during the week. In addition to the ongoing moderate to severe drought conditions in northwest Iowa and Minnesota, moderate drought (D1) has developed in central Illinois, as indicated by the most recent release of the U.S. Drought Monitor (Figure 7).
A majority of this week's rain in Missouri fell on the 13th as a frontal system moved through the region (Figure 8). The heavy rain continued on April 14th, producing high rainfall totals across Iowa and northern Illinois (Figure 9). The high precipitation totals from Iowa and Illinois on the 14th are not reflected on the weekly map since this rain is reported by cooperative stations on the following day (April 15th). Several daily precipitation records were set throughout the week, with the majority occurring on April 13th and 14th in Missouri, Iowa, and Illinois.
Severe Weather Late in the Week
A severe weather outbreak occurred across the Great Plains on April 14th. The severe weather stretched into the western Midwest, bringing tornadoes, high winds, and large hail into southern Iowa (Figure 10). Preliminary reports indicate there were 7 tornadoes in Iowa. A tornado in Thurman, Iowa (Fremont County) destroyed 75% of the town, but luckily, no major injuries were reported. Damage survey results from the National Weather Service assessed that it was an EF2 tornado, with a path length of 10.8 miles and maximum winds of 125 miles per hour, that went through Thurman. A National Weather Service Storm Survey confirmed that a strong EF2 tornado touched down in Creston, Iowa (Union County).
In addition to the tornadoes, there were 46 high wind reports in southern Iowa and northwest Illinois and 32 large hail reports in southern Iowa. The airport in Oskaloosa, Iowa (Mahaska County) recorded a wind gust of 97 miles per hour. Hail reports of 2.5 to 2.75 inches were reported in Murray, Iowa (Clarke County) and Eddyville, Iowa (Monroe County), respectively.
Cooler April Temperatures Bring Freeze Impacts
During the record warmth in March, many crops and plants in the Midwest were planted or started blooming several weeks early. During the second week of April, freezing temperatures spread across the region (Figure 11), putting early emerging crops and plants at risk. Several freeze warnings were issued by the National Weather Service on April 10th and 11th.
According to the USDA, fruit crops in the northern Great Lakes (which include cherries, peaches, strawberries, apples, and grapes) will be some of the most sensitive crops to freezing April temperatures this year. In fact, it is estimated that the frost during the second week of April took out 10,000 acres of grapes in Michigan. Apple orchards in Minnesota and cherry orchards in Michigan were also affected by the freezing temperatures and continue to be concerned about the possibility for more freezes.
-MW-
The Michigan State Climatologist Office also contributed to this report.
The Minnesota State Climatology Office also contributed to this report.