Midwest Weekly Highlights - April 1-9, 2011

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Warmth Returns

Temperatures were generally above normal across the Midwest during the first nine days of April. Departures ranged from near normal in the eastern parts of the region to as much as 7°F above normal (Figure 1). Cool weather gave way to much warmer temperatures as warm south winds on Apr 3rd and 4th pushed temperatures as much as 20°F above normal. Numerous record high temperatures were recorded.
 

Variable Precipitation

Precipitation for the first nine days of April was heaviest in the eastern reaches of the Midwest with up to 2" (Figure 2). The driest areas were northern Iowa and west-central Minnesota where less than a quarter inch fell. Viewed as a percentage of normal precipitation, the dry locations noted above received less than 25% of normal while some areas from the Iowa-Missouri border spreading eastward to as far north as lower Michigan and as far south as eastern Kentucky received more than 150% of normal (Figure 3). In Minnesota, along the Canadian border, precipitation totals topped 300% of normal.
 

Drought

Drought remained sparse across the Midwest in early April (Figure 4). Moderate Drought conditions continued in northeast Minnesota and northern Michigan, areas accounting for less than 3% of the Midwest. Abnormally Dry areas were also noted in parts of Iowa, Missouri, Indiana, and Ohio.
 

Another Spring with Major Flooding on the Red River

The expected flooding along the Red River in western Minnesota quickly ramped up to Major Flood levels early in April (Figure 5). Wet soils in the fall and heavy winter snows created a high likelihood of flooding this spring. Despite drier conditions early this spring, melt water from the extensive snow pack pushed river levels to near record levels in Fargo (Figure 6) and peaks will move north as the water continues to move downstream. There was also Minor and Moderate Flooding in southern Minnesota and along the Mississippi River south to St. Louis, Missouri.
 

Severe Weather Outbreak April 3rd and 4th

A cold front pushed into the Midwest on April 3rd (Figure 7) triggering severe weather from northern Missouri to southern Wisconsin and northern Indiana. Three inch hail was reported in Dubuque County, Iowa and Cass County, Missouri and 2.75" hail fell in Dane County, Wisconsin. Among the 147 reports of hail 1" or bigger were 18 reports of hail 2" and bigger came from Jackson County, Missouri and the above counties.

As the front pushed southeast on April 4th, a severe weather outbreak affected most of the southeast US with over 1300 severe weather reports (Figure 8), the most in over ten years. In the Midwest, Kentucky was hard hit with multiple tornadoes (10 Kentucky counties) and 100 reports of severe thunderstorm winds. Near Hebron, Ohio (Licking County) was hit with a tornado and Illinois, Missouri, and Ohio also reported damage from thunderstorm winds.
 

April 9th Kicks Off Another Round of Severe Weather

A cold front triggered tornadic storms in northwestern Iowa on the 9th (Figure 9) with ongoing severe weather into the next week. An EF3 tornado destroyed more than 100 homes in Mapleton, Iowa (Monona County). Fortunately, only two people were reported injured. Tornado reports came from eight Iowa counties.
 

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