AccuWeather.com reports although fall doesn't officially begin until Saturday, Sept. 22 at 10:49 a.m EDT, the weather will take a decidingly cool and showery turn across the Great Lakes beginning today.
A cold front that swept eastward through Wisconsin and Illinois Wednesday night ushered in cool air and thundershowers. The end of the workweek will feature unsettled weather across the region as a series of disturbances dives into the area.
Residents of the region will no doubt need a jacket to combat the windy, cool and showery conditions over the next several days.
A persistent, gusty, northwesterly wind through the weekend will keep temperatures well below normal with some locations toward the Canadian border struggling to reach 60 degrees.
Nighttime temperatures will be especially crisp with numerous readings in the 30s and 40s. Even the suburbs of Chicago could see temperatures in the 30s by Saturday night!
In addition the fall-like temperatures, showers will become more numerous. The most widespread wet weather is expected Friday across the entire region with the shower focus shifting to the typical lake-effect prone areas by the weekend. Some locations can even hear a few rumbles of thunder.
While this is a chilly air mass for September, it is not expected to be cold enough to bring lake-effect snow. However, the coldest punch of air forecast to dive into the arrowhead of Minnesota and northern Wisconsin Friday night could cause a few snowflakes to mix in with the rain showers. Although no accumulation is expected, it would certainly be a harsh reminder that winter is on the way!
Aside from the showers and cool weather, waterspouts are a possibility on the Great Lakes this weekend. The relatively warm water temperatures can interact with the cool air and spin in the atmosphere to produce funnel clouds.
By the start of next week, the brisk northwesterly flow should relax, putting an end to the showery weather regime.
While much of the eastern U.S. sees cooler-than-average temperatures, residents of the West will continue to have unusually warm weather and poor air quality.