MICHIGAN — The Storm Prediction Center has highlighted portions of southern Michigan within a mesoscale discussion area they are monitoring for severe weather overnight, with a 40 percent chance of a watch being issued for areas within the outlined zone. The discussion is valid until 1 a.m. EDT Saturday, September 5th, and includes cities such as Kalamazoo, Holland, Battle Creek, Portage, and Adrian at risk. Potential threats include hail up to 1.25 inches in diameter and wind gusts ranging from 55 to 70 mph, with more than 17 million people currently included within the broader alert area.
Mesoscale Discussion Outlines Broad Overnight Threat Zone
The Storm Prediction Center’s mesoscale discussion, issued for the overnight hours and valid until 1 a.m. Saturday, outlines a broad area stretching from the Chicago and Waukegan region through South Bend, Fort Wayne, and into southern Michigan near Jackson and Lansing. Radar imagery already shows organized lines of thunderstorms with embedded intense cells moving through portions of this outlined zone.
This type of mesoscale discussion represents a step below a full severe thunderstorm or tornado watch, serving as an advance notice that forecasters are closely monitoring conditions and see a meaningful probability that a formal watch could be issued in the coming hours as the situation develops further.
The geographic scope of this discussion area is substantial, spanning portions of northern Illinois, northern Indiana, and southern Michigan, reflecting the wide reach of the atmospheric setup currently being evaluated by Storm Prediction Center meteorologists for overnight severe weather potential.
Forty Percent Watch Probability Reflects Meaningful Risk
Forecasters have assigned a 40 percent probability that a formal severe thunderstorm or tornado watch will be issued for areas within the highlighted blue circle before the discussion’s expiration at 1 a.m. Saturday. While this does not guarantee a watch will ultimately be issued, a 40 percent probability represents a meaningful level of confidence that conditions could support upgraded warnings later in the overnight period…