Days of unseasonably low temperatures ahead
The next seven days, high temperatures are expected to stay in the 70s with readings barely making the 70-degree mark Thursday. Canadian-source high pressure will dominate our weather, as the upper-air wind pattern will show a huge ridge of high pressure over the western U.S., while north-to-northwest air flow associated with a low-pressure trough over the northeastern U.S. will bring almost continuous reinforcing surges of cooler air into the Great Lakes and Chicago area. Thursday, the coldest air will be overhead, the very unstable atmospheric conditions likely producing widespread cloudiness and even a few brief showers or sprinkles. This pattern is also supportive of low pressure developing in the Gulf of Mexico and off the Florida coastline, where tropical storms could develop.