The notable moisture increase and subsequent clearing skies overnight associated by the passage of the remnant hurricane Irma low pressure center through southern Illinois and Indiana Wednesday is expected to lead to extensive dense fog over the Chicago area and adjoining Lake Michigan Thursday morning. With abundant sunshine and light southerly winds, temperatures should approach the 80-degree mark Thursday afternoon.
A significant reversal appears in store – warming is then expected with temperatures in the 80s for at least the next 6 days and readings averaging nearly 10-degrees above normal for the period September 15-23.
We are also running behind on rainfall this month at Chicago’s official O’Hare observing site with only a quarter-inch measured through Wednesday. An increase in moisture along with the close proximity of frontal boundaries could lead to some shower/thunderstorm activity here next week, beginning Sunday.
