The first in a series of cold fronts passed through the area overnight, bringing drier air and ending the threat of showers. Despite the emergent sunshine, temps are expected to run about 7 degrees below normal Monday as a high-amplitude wave in our upper-level wind flow moves across the Great Lakes. This scenario is forecast to repeat itself two more times over the next week, leaving little chance for summertime air masses to become established across the Midwest. Starting June 15, the average high temp in Chicago reaches 80, peaking at 85 in mid-July. To date, the city has officially logged only eight 80-degree days. Summer heat will remain scarce through midmonth due to the cold fronts. Longer-range forecasts support a more typical June weather pattern developing toward the end of next week.