Midwest Weekly Highlights - September 1-7, 2015

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Wet Great Lakes, Dry South

Wet conditions dominated the landscape across much of the Great Lakes to start September while southern parts of the region stayed dry (Figure 1).  More than an inch of rain fell across Minnesota, northern Wisconsin, Michigan, southern Iowa and northern Missouri.  More than twice the normal amount of rain fell across these areas in many cases (Figure 2).  Meanwhile, little to no rain fell across southern Missouri, Kentucky and most of Illinois. Departures of up to an inch below normal were common in these areas (Figure 3).
 

Hot Start to Fall

While the summer trended slightly cooler than normal, the first week of autumn was quite warm.  Average temperatures soared well above normal across the entire region (Figure 4).  Minnesota, Wisconsin, Iowa, Michigan and northern Illinois all saw temperatures 8°F above normal or more, with most of Minnesota 10-14°F above normal.  Temperatures were more moderate in the southern parts of the region, but temperatures were still 3-6°F above normal.  High temperatures averaged in the 90s across Missouri, Illinois, southern Indiana, and western Kentucky while the rest of the region dealt with high temperatures in the 80s (Figure 5).  Lows only cooled into the 60s overnight (Figure 6).

Many stations across the region had their hottest days this year during the period.  In Illinois, Urbana had its hottest day of the year on September 4 at 93°F while Chicago’s O’Hare Airport tied its hottest day at 92°F on September 6 (Figure 7).  In Kentucky, the hottest day of the year was set at the Cincinnati Northern Kentucky Airport in Covington (93°F) on September 4 and at Bowling Green Warren County Airport (97°F) on September 5th, The Louisville International Airport (95°F) and the Paducah Barkley Regional Airport (96°F) also tied their hottest day of the year on September 5 (Figure 8).
 

Severe Storms

A fair amount of severe weather occurred in the region to start the month of September (Figure 9).  A majority of these severe storms happened on September 3-4.  On September 3, a cluster of storms moved through southeast Michigan, causing wind damage into the Detroit area.  September 4 had severe storms from east-central Illinois through central Ohio.  Wind and some one inch hail were reported.  The home opener for Illinois football was postponed due to one of these storms, as the thunderstorm stalled over the stadium right before the late kickoff time of 8pm, forcing the team to move the game to September 5 for player and fan safety.
 

Drought Conditions Improve in Wisconsin, Minnesota

Soaking rains in the arrowhead of Minnesota and southwest Wisconsin allowed for moderate drought conditions to be removed from these areas in the latest drought monitor (Figure 10).  Some moderate drought remained in southwest Wisconsin, however, north of the Wisconsin River.  A few other areas of abnormally dry conditions were found in Ohio, central Kentucky and northern Michigan, but over 90 percent of the region had no drought concerns.

-BJP-