Winter Rallies Back in March

As time in the 2016-2017 winter season went by, the snowless-ness continued across the Midwest courtesy of a January and February that finished with unprecedentedly meager numbers and mild temperatures. Ironically, the transitional month of March brought some winter back to the region, in some cases in record numbers. Old Man Winter’s frosty grip did not totally dominate the month as some of that warm influence of the previous two months would intervene at times. However, it proved to be a bumpy, and at times, chilly ride into the spring season.

FIRST, SEVERE WEATHER… THEN COLD

Before the cold air returned, the first week of the month was more of the same for the Midwest – mainly warm, on the order of 5 to 15 degrees above normal. This was enough fuel to spark a major outbreak of severe weather from the eastern side of the Plains into the state of Illinois on the 6th. Multiple tornadoes were reported across the state, and while none were observed in Chicago itself, there was still a large amount of wind damage.

A change followed not long after this outbreak, as a late-season Arctic front slid south of the Ohio Valley. Cold air funneled down through the Midwest gradually from the 9th into the 10th. By the time the 11th hit, high temperatures were as much as 25 to 35 degrees colder than they were just two days prior.

This cold air set the stage for the long-awaited return of snow. Never before had Chicago gone a full back-to-back January into February with such little snowfall. This changed in a big way from the 12th into the 14th as a winter storm barreled across the Lower 48, eventually becoming a major snow maker for Northern Illinois.

A two-part snowstorm, the first round of snow pushed through the area early on the 13th producing a general 2 to 5 inch snowfall across a good chunk of Illinois as an upper level disturbance streaked along the Ohio River Valley. However, Indianapolis thru Columbus, Dayton, and Cincy only managed a coating to 1.0" of snow from the system. This disturbance eventually became a major winter storm for the east coast, whose influence stretched all the way back to the Midwest, in the form of steady north-northeast winds and resulting in rare March lake effect snow. In some instances, especially along the Michigan lake shore itself and through the Chicago Metro, totals reached 8 to 16” inches in the 3 day span (for reference, a reporting station in Kenosha reported a record 3 day snowfall through the 14th of 16”).

 

Heavy lake-effect snow is rare here, so I’ll enjoy this while it lasts. #ilwx pic.twitter.com/3680Fm5T38

— Robert Guico (@lpangelrob) March 14, 2017

 

Despite this return to winter, the rest of March behaved similarly to prior months, with very warm conditions. It was a stark contrast in fact. On average, the region was about 5 to 10 degrees below normal during that cold stretch, whereas the rest of March stayed well above normal, around 5 degrees or so above. The 24th and 25th proved to be the warmest for all areas, with mid to upper 70s common from Indy through Ohio. However, these temperatures didn't reach the extremes which northern IL experienced, as the old record of 80° (1939) at O’Hare was broken by a high of 82° on the 24th.

TWO SEASONS IN A FEW HOURS

That particular day of the 24th, weather in Chicago changed drastically later in the afternoon. A back-door cold front was the culprit, which dropped temperatures at Chicago Executive Airport (KPWK) from near 80 degrees at 4 PM to the middle 40s by 6 PM.

 

A WET MONTH AS WELL

March 2017 was a highly active month, making for surplus numbers in the rain gauges. All of the major cities across the Cornbelt recorded well-above average rainfall, but the winner above all was Columbus, OH. Not only did the total of 5.39” best the average of 3.02” for the city, but it also was the 5th highest total rainfall on record. Regardless, precipitation averages finished 200 to even 300% above normal in some parts of the region even outside of the major cities.