It’s been chilly in Chicago the past couple of days with highs holding in the in the 20s, but milder weather is slated to return this weekend. The warm-up will be modest on Saturday with readings climbing into the middle 30s, but the mercury is expected to reach 40 degrees by Sunday. The mild conditions will continue into Tuesday with highs expected to reach the lower 40s daily. Some rain will develop late Monday and continue into Tuesday. Colder weather will return Tuesday night as strong and gusty northwest winds sent temperatures tumbling into the 20s changing the rain to snow with the possibility of enough snow to whiten the ground by Wednesday morning. If that occurs it could be the city’s first official snow cover since they day after Christmas. Checking weather records dating to 1885 bare ground occurs in only one in four years in February’s opening days.