Chicagoans just experienced two straight days with high temperatures below 65-degrees – pretty rare for this early in the fall - it has happened only 8 times previously in the 54-year record at O’Hare International Airport.
As high pressure drifts off to the east, warming will take place the next few days under the growing influence of strengthening southerly winds. Temperatures will jump about 10-degrees into the low to middle 70s Tuesday, reach the 80-degree mark Wednesday and then the middle – possibly upper 80s Thursday before a cold front is followed by cooler high pressure Friday into the coming weekend.
While some rainfall will occur with a warm front Wednesday, Thursday converging southwest winds will feed warm moisture-laden air with dewpoints well into the 60s ahead of an approaching cold front – setting the stage for a period of active, downpour-generating thunderstorms Thursday night. Before it’s over Friday, some locations could receive as much as an inch or more of welcome rains.