April 22-30, 2010
Midwest Weekly Highlights - April 22-30, 2010
Temperatures Near Normal
For most of the Midwest, temperatures were near normal (within 2°F of normal) over the last nine days of April. The thumb of Michigan had temperatures 2 to 4 °F below normal and Minnesota and northern Iowa averaged 2 to 6°F above normal (Figure 1). Sixty-five daily temperature records were set over the nine-day period. Included in that total were 25 record high minimums on the 30th as low temperatures warmed 20 to 25 degrees in two days due to strong southwest winds (Figure 2).
Precipitation Returns
Precipitation returned to most of the region following a dry week. In the southwest half of the Midwest, totals ranged from one inch up to four inches in northern Missouri. Totals in the northeast half of the region were generally less than an inch and ranging all the way down to just a few hundredths of an inch in northern Michigan, though a few locations in Wisconsin, Indiana, and Ohio received closer to two inches (Figure 3). Totals were twice the normal amount in east central Wisconsin, northeast Indiana, northwest Ohio, central Kentucky, west central Illinois, southern and central Iowa, and northern Missouri (Figure 4). The US Drought Monitor on Apr 27th expanded the moderate and severe drought in the upper Midwest (Figure 5).
Strong Winds
Ahead of a storm system moving into the region on the 29th, a sharp pressure gradient led to strong southwest winds, up to 45 miles per hour, impacting the region (Figure 6). Reports tied to the winds included a shattered school bus windshield in Davenport, Iowa injuring four students who were treated at a hospital. A semi was also blown off Interstate 57 in central Illinois.
Flooding in Missouri
Flooding returned to Missouri on the 25th following heavy rains. Flooded conditions were reported along the Greene, Missouri, and Mississippi rivers. River levels only reached minor flood stage and then dropped quickly.
Slow Moving System Brings Severe Weather to the Midwest April 22nd to 25th
Early in the week a system slowly moved across the southern half of the Midwest (Figure 7). The first severe weather reports were on the 22nd in Missouri along a leading warm front. Two incidents of large hail was reported (Laclede and Pulaski counties).
On the 23rd, reports of wind damage, large hail, and tornadoes were spread across Missouri. Five tornado reports were logged in Warren and Lincoln counties. Several large hail reports came in with 1.75" hail in Hickory and Benton counties. Thunderstorm winds were responsible for tree damage in Hickory County and a vehicle blown off the road in Daviess County.
The 24th brought severe weather from northwest Iowa to Kentucky. Tornadoes were reported in Missouri (Nodaway, Taney, and St. Louis counties) and Kentucky (Edmonson, Christian, and Mercer counties). Hail reports were scattered along a line from the northwest corner of Iowa through the St. Louis area and then across southern Kentucky. The largest reports (1.75") were near Lester, Iowa (Lyon County), Hull, Iowa (Sioux County), and Corbin, Kentucky (Whitley County). Wind damage was reported in southeast Missouri, southern Illinois, and Kentucky. An 84 mile per hour wind gust was reported at Ozark, Missouri (Christian County) and gusts to 70 miles per hour were reported in Illinois and Kentucky.
On the 25th the system pushed further east bringing hail and wind to Ohio. The wind damage was limited to trees and hail reports were mostly 1" with 1.25" hail reported in Zanesville, Ohio (Muskingum County).
Second System With Severe Weather on April 29th and 30th
Late in the month another system pushed into the region from the west. On the 29th severe weather was confined to a line cutting across Iowa from southwest Iowa to near Austin, Minnesota. A tornado touched down just west of Glenwood, Iowa (Mills County) blowing cars of Interstate 29. Hail and tree damage was reported along a narrow line to the Iowa-Minnesota border. The largest hail reports were 1.75" in Iowa's Greene and Cerro Gordo Counties.
Severe weather on the 30th affected a much larger portion of the Midwest. More than a dozen tornado reports came in from three states. In Trigg County, Kentucky there was a report of a possible tornado that destroyed a building in the Land Between the Lakes area. Southeast Missouri was the location of several reports all within a little over three hours (Ozark Howell, Jefferson, and Iron counties) causing damage to numerous homes. In Wisconsin, there were three tornado reports near Berlin (Green Lake County), Glen Oak (Marquette County), and Princeton (Green Lake County). The Berlin tornado took down several high tension power poles. The Glen Oak tornado was reported on the ground for 8 miles but damage was limited to trees. Wind and/or hail was reported across eight Midwest states sparing Ohio. Three inch hail was reported at the Kansas City airport (Platte County) around 8:45 in the morning. Wind gusts reached 80 miles per hour near Burksville, Illinois (Monroe County). Damage was widespread with tress and power poles down in many Midwest locations. A roof was blown off a garage near La Cresent, Minnesota (Houston County) and another building was damaged near Willow Springs, Missouri (Howell County).
-MST-