Chicago’s warming trend begins Tuesday
Today’s expected high temperature near 70º should be the coolest of the week, because a multiday period of rising temperatures begins tomorrow. The culmination of the warming—Saturday’s anticipated high of 88º—should it come to pass, will be Chicago’s warmest temperature in 294 days (that’s four-fifths of a year!) since the city registered 90º last Aug. 3.
A realignment of upper-level winds (above 10,000 feet) is triggering the warming—not just here but across the two-thirds of the nation east of the Rockies. Computer models tell us that persistent northwesterly upper-flow, instrumental in recent days in directing cool Canadian air to the Midwest, is about to give way to a multiday period of upper-level southwesterlies.
Six consecutive days of warming, while noteworthy, challenges no records. From April 22 through May 2, 1901, Chicago logged an 11-day spell of rising temperatures that carried daily highs from 40º (April 22) to 87º (May 2).