Midwest Overview - September 2008
A Wet Start, Dry End
Two tropical systems, Gustav and Ike, brought heavy rain to the central Midwest during the first half of September. Most locations from Missouri through Illinois into southern Michigan received two to three times normal September rainfall, and much of that rain fell the first two weeks of the month. A number of locations set monthly records for precipitation. Dry weather settled in the last half of the month, and rain was generally limited to scattered showers and thunderstorms associated with frontal passages.
While the central Midwest experienced soaking rains, the northwestern and southeastern portions of the Midwest were very dry (Figure 1). Precipitation in Kentucky and southern Ohio was only 20 percent to 40 percent of normal, and precipitation across central Wisconsin was less than 50 percent of normal.
Temperatures this month varied from below normal in the western portions of the region, where clouds and rain were more prevalent, to above normal in the east. Average daily temperatures ranged from 2°F below normal in western Missouri to 3°F above normal in central Ohio (Figure 2). Temperatures across the upper Midwest were 1°F to 2°F above normal.
Active Tropics Affects Midwest
As the month began Hurricane Gustav made landfall on the Louisiana Gulf Coast and then slowly drifted northward. Heavy rain fell from Missouri through Illinois and into southern Michigan as the system lifted out across the Midwest (Figure 3). A week later, Hurricane Ike made landfall along the Texas Gulf Coast, and brought additional rain to much of the same area that received heavy rain with Gustav as it followed a path through the Midwest similar to Gustav (Figure 4). The remnants of Ike also produced a swath of wind damage from southern Missouri through Kentucky, southern Indiana, and Ohio (Figure 5). Details on the impacts of this storm can be found in the September 10-16 Climate Watch.
For more details on weather and climate events during September 2008, click on the individual weekly report links on the upper right.