April 19--With low pressure moving through the Chicago area from the west, Sunday looks to be a cloudy, windy, cool day and the prelude to a cool week ahead. Highs on Sunday will struggle to rise out of the 50s with a strong east to southeast wind holding lakefront readings closer to the 50-degree mark. A few thunderstorms in the widespread rain will result in downpours that could lead to over an inch of rain in a few official area rain gauges.
An upper-level "closed-off" low pressure center will slowly drift east across the Great Lakes during the week ahead. A strong blocking pattern will be established with a northwest flow aloft continually steering cool air out of northern Canada into the Great Lakes, the Midwest and the Chicago area. That will result in an extended period of mostly cloudy skies, periodic light showers early in the week and cool weather, with readings averaging some 6 to 10 degrees below late April norms, quite a reversal from the well above normal temperatures experienced the first 17 days this month.
