April 1-7, 2010
Midwest Weekly Highlights - April 1-7, 2010
Very Warm Temperatures
A very warm April Fool's Day kicked off a week that remained well above normal. Western Iowa and southwest Minnesota were 6° to 10°F above normal while the rest of the Midwest saw double digit temperature departures with northeast Ohio nearly 20°F above normal (Figure 1). More than 1000 record high temperatures were set across the region with at least 60 record highs in each state (Figure 2) and at least 40 record highs each day. There were no record low temperatures recorded during the week.
Widespread Severe Weather but Heavy Rainfall More Limited
The warm temperatures brought convective storms to the region. Severe weather was reported in each state during the week (Figure 3). Despite the widespread severe weather, rainfall ranged from less than 10% of normal to over 300% of normal (Figure 4). From central Missouri to lower Michigan rainfall totals were more than double normal amounts. To the southeast and northwest, totals dropped off to less than 50% of normal. Parts of Minnesota, Kentucky, and Ohio received less than 10% of normal. The US Drought Monitor for April 6 expanded drought in the upper Midwest across upper Michigan and into the northern end of lower Michigan.
Minnesota Lakes
The warm March and early April temperatures brought an early end to the ice on most Minnesota lakes. Ice remains only on some of the larger, deeper lakes in northern Minnesota. Some lakes in northern Minnesota experienced a record early ice-out due to the warmth this spring. In southern Minnesota, the winter's heavy snow caused one of the biggest winter fish kills on record, the worst in many decades according to the locals. Minnesota Department of Natural Resources estimate fish kill at around 10,000 fish.
First Midwest Twisters of the Season
On the evening of the 4th, northern Missouri was under a tornado watch (Figure 5) and twisters touched down in three counties (Howard, Randolph, and Audrain counties). One tornado hit Illinois on the afternoon of the 5th (Montgomery County) while central Illinois was also under a tornado watch (Figure 6). Reported damage from all the tornadoes was limited to trees.
Hail Over 2" in Three States
There were more than 150 hail reports during the week. Hail reports of 2.00" or greater came from Missouri (2.50" in Carroll County and 2.00" in Pike County) on the 4th, Illinois (2.75" in Cook County) and Indiana (3.00" in Owen County, 2.50" in Morgan County, and 2.00" in Hendricks County) on the 5th, and Iowa (2.50" in Black Hawk County and 2.00" in Fayette County) on the 6th. Also on the 6th, Grinnell College track team members were struck with hail during a training run and several were treated at a local hospital (Poweshiek County, Iowa).
Widespread Wind Damage
Widespread wind damage was reported during the week with more than 140 reports documented at the Storm Prediction Center. Reports included trees and power lines down, highway signs down, vehicles blown off the road, semi-trailers overturned, roofs blown off buildings, and barns and sheds damaged or destroyed. Homes also were damaged, ranging from lost shingles or siding to damaged roofs and destroyed garages and carports. Most of the reports were south of a line from northern Iowa, across far northern Illinois, to southern Michigan.
Cherry trees and grape vines in southern Michigan lost buds, and in a few cases some bark, as strong winds and hail moved through early morning on the 6th.
Power outages affected tens of thousands in the Midwest due to the convective weather. The number of customers affected by outages were in the hundreds in Indiana, in the thousands in Iowa, Michigan, and Ohio, and in the tens of thousands in Illinois and Missouri.
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