As the winter and spring seasons battled it out through April 2016, the Midwest experienced everything from extreme temperature swings to snow events and even its first taste of severe weather. After a rather abnormally warm winter for the Corn Belt States, this was the first month to finish near to even below normal for many spots. Let’s review all that Mother Nature threw our way in this transitional month.
The cool air made slow progress south and east, so on April Fool’s Day temperatures across Ohio in Columbus and Cincinnati were still about 5 degrees above normal with readings in the 60s! Some impressive single day temperature ranges followed on Sunday April 3rd with Chicago measuring a morning low of 26°F before soaring to a high of 71°F. This 45°F temperature swing in one day was the largest single day range since Jan 2008, ties for the 13th largest calendar day temperature swing on record, and ranks as the largest daily range in April since 1936! Interestingly, the 30+ degree temperature swing that occurred each day from April 2nd to April 4th (Saturday high 40°F, Sunday 45°F and Monday 38°F) has happened only three times since 1871 and only once in the past century!
Despite the spike into the 70s on the 3rd in Chicago, most areas experienced several days of cooler than normal temperatures that lasted until April 14th. It was even cold enough for snow. In fact, before warmth in northern Illinois, a clipper system brought cold and blustery conditions on the 2nd. This quick mover also caused snow showers and snow squalls with up to an inch of snow in spots across northern Illinois. Needless to say, it did not feel like spring at all, with highs in the 40’s and lows around freezing.
Another disturbance crossed the area on the 8th. Northwest winds, which prevailed over the first two weeks of the month, ushered in colder air and another period of occasional snow. Chicago even dealt with some squalls on the night of the 8th with brief whiteout conditions and additional coatings. While not a significant amount of snow for the big cities, the storm system did dump four to as much as nine inches of the white stuff over northern Ohio!
Being a transition a month, we typically expect drastic changes in April and that’s exactly what the Midwest experienced in 2016. How much so? After 14 chilly and sometimes snowy days during the first half of the month with average temperatures departures from 6 to 8°F below normal in Chicago, Indy and the major Ohio cities, the region saw a virtual 180 degree turnaround by the 15th. In fact, temperatures on the 15th reached 68°F at O’Hare, and up to 73°F in Columbus, OH, and 75°F for Indianapolis, IN. The result was a 20°F+ swing in overall averages between the 1st and 2nd half of the month! Generally dry conditions accompanied the warm up as high pressure dominated.
The surge of warmer air experienced in the latter portion of the month eventually led to severe weather. This is a typical characteristic of spring in the Central United States, as the retreating cold of winter interacts with increasingly warmer air of the transitional spring season. On April 26th, an approaching cold front set off the most significant severe weather outbreak for the month. The outbreak produced a tornado that damaged a barn near Worthington, Indiana while numerous reports of structure damage, downed trees and power lines from strong winds occurred across southern Illinois eastward through southern Indiana and Ohio. Hail up to 1 inch in diameter was also reported in the same areas. The largest hail was 3 inches in diameter and fell near Pankeyville, Illinois. While April 27th saw a significant decrease in the number of damaging wind and hail reports, there were Two brief touchdowns of EF0 tornadoes confirmed.
Given the ups-and-downs through the entire month, April turned out to be the first month to break the string of above-normal monthly temperature departures since November 2015 with many near or just below normal. Although precipitation departures mainly finished around average, some saw a surplus of near 125%. Indianapolis even finished with a surplus of 2.1 inches. We'll have to wait and see if Mother Nature gives us a break from the wide variety of weather in May 2016. See next month's newsletter to find out.
