Midwest Weekly Highlights - September 1-9, 2013

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Mostly Dry in the Midwest, but Heavy Rains in Some Locations

The Midwest was mostly on the dry side for the first nine days of September (Figure 1). The driest area spanned the Iowa-Wisconsin border were no rain fell during the period (Figure 2). However, a few locations had above normal rains, and were well above normal. West central Minnesota and from the Ohio River Valley south across Kentucky received above normal rain, as did the eastern part of Upper Michigan on the 9th. The heaviest rains were in Chippewa County where radar estimates topped 5", flash flood warnings were issued, and sections of two roads were washed away.
 

Temperatures Soar in the West

Temperatures soared into triple digits by the end of the period, breaking records especially in Iowa and Missouri. Temperatures across the region ranged from slightly cooler than normal in the east along the Great Lakes coastline to more than 5°F above normal along the Iowa-Missouri border (Figure 3). On the 9th (reported on the morning of the 10th), maximum temperatures reached triple digits in southeast Iowa, northeast Missouri, and west central Illinois (Figure 4). Daily temperature records included a handful of record lows but record highs accumulated by the dozen.
 

Drought Expansion Affects Crops

The hot and dry conditions in much of the Midwest led to an expansion and intensification of drought in the region. The September 10th US Drought Monitor (Figure 5) showed areal increases in drought (moderate drought or worse, 32%) and severe drought (11%). Crop conditions continued to deteriorate and yield estimates dropped as impacts on the corn and bean crops materialized.
 

Severe Weather Scattered Around the Midwest

Although severe weather reports were not numerous, they were spread across the Midwest (Figure 6). The busiest day was the 1st but additional reports were also posted on the 2nd, 7th, 8th, and 9th. A brief tornado touched down on the 1st near Serena, Illinois (LaSalle County) but there was no damage found by the NWS storm survey. Scattered reports of hail sized 1" to 1.25" and damaging winds - that mostly were reported to affect trees and power lines - came from six of the nine states in the region. Iowa, Indiana, and Kentucky had no reports during the period.
 

-MST-
The Iowa Climatology Bureau also contributed to this report.