Cool Weather Bookends a Warm September 2016

Posted: October 5, 2016, 1:10 pm by ccastellano

September began on a fairly cool note in the Midwest as the first three days of the month averaged anywhere from 2 - 6 degrees below normal (highs in the mid to upper 70s and lows in the 60s to even the upper 50s). The cooler spell would not last, however, as around a week of 80 degree plus days followed after the 4th. In fact, some of the hottest days of the month occurred in this span, with Rockford, IL reaching 92°F and Chicago, IL hitting 91°F both on the 6th. In addition, Indianapolis, IN, Dayton, OH, and Columbus, OH all hit 90 degrees on the 7th with even a heat wave of three consecutive 90 degree days in Cincinnati from the 6th - 8th.

A vigorous cold front then ended the warm weather on the 9th and 10th and produced severe weather across the Midwest during the two day span.  At first, the boundary triggered a pair of tornadoes in Illinois' eastern border counties of Champaign, Vermillion and Clark. The more significant of the two was the twister which touched down in Homer, IL, which produced significant damage according to reports. This cold front became more organized as an area of low pressure streaked through the Great Lakes and strengthened on its march east. Ohio bore the brunt of this storm system, with widespread reports of wind damage across the state.

 

 

After the severe weather, warmer than normal weather returned mid-month from Illinois through Ohio with even a few 90 degree days once again. In fact, Dayton reached 90 on the 22nd and Cincinnati fell just short of another heat wave from the 21 - 23rd, with temperatures of 89, 90, & 90 respectively. Indy and Chicago fell a few degrees shy of the Ohio heat, reaching the mid to upper 80s a few days prior. Although the last several days of the month did cool back down, the warmth prevailed across the Midwest with September finishing 5.0 - 6.5 degrees above average as a whole.

 

September 2016: Cool to Start, Cool to Finish, But Warm Overall

 

First 3 and Last 3 Days

Rest of September (4th thru 27th)

O'Hare

68.7 (-5.8o)

79.9 (+5.0o)

Rockford

72.5 (-1.7o)

80.7 (+4.8o)

Indianapolis

72.5 (-3.9o)

83.1 (+5.0o)

Cincinnati

73.0 (-4.0o)

84.8 (+6.2o)

Dayton

70.0 (-4.8o)

83.0 (+6.6o)

Columbus

71.0 (-5.2o)

83.0 (+5.5o)

 

While most of the Midwest finished with a surplus of rainfall, northern Illinois fell well short of the average with Chicago's O'hare Airport receiving 1.76" of rainfall, which was 37% below the mean and 19th driest on record. It's facinating the dry weather occurred while places just north and west in northern Iowa and Wisconsin saw a significant amount of rain for the month, on the order of 200 to 300% above. Meanwhile, Indy through central Ohio finished out 1 - 2" above normal with a little over 4.50 inches for the month, but further south in Cincinnati, a small deficit in rainfall was recorded. 

 

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