Heavy rains are likely to follow a brief warm-up
Saturday's weather in Chicago was more reminiscent of late March, with gusty northwest winds, cloudy skies, scattered showers and high temperatures barely making it into the 50s. Sunday marks the start of a rapid turnaround with sunny skies, southwest winds and temperatures some 10 to 15 degrees higher. Warming peaks in the mid-70s Tuesday. Showers and thunderstorms, featuring downpours and heavy rains, precede the arrival of a cold front later Tuesday night. This storm system signals a change in the upper air pattern featuring a strong west-to-east jet stream flow directly overhead.
STORMS TRACK THROUGH THE MIDWEST
The rain-free period forecast from Sunday into Tuesday may be the longest seen in northeast Illinois for some time. Beginning Wednesday, low pressure systems will move frequently out of the central Plains through the Midwest and Ohio Valley. Computer models indicate that for the next couple weeks in Chicago, periods of cloudiness and showers will linger longer than the infrequent intervals of clearing skies. Starting Wednesday, a cool easterly air flow off Lake Michigan will probably persist well into the weekend. Rains should hit Thursday and then again over the weekend.