Tropical Depression 18 to strengthenThe first day of autumn brought cooler temperatures, but the Atlantic is still hot and a new threat is on the horizon. CNN meteorologist Derek Van Dam has the details.
Cool morning with slight storm chances SaturdaySaturday will bring slightly cooler temperatures with storm chances possible this afternoon and evening.
Metro Detroit Forecast: Cooler and more comfortableTemperatures and the humidity are down today. Mostly cloudy with a high of 76°, and a slight chance of an isolated shower.
A slight chance of thunderstorms continues through the weekend
![Tropical Depression 18 to strengthen [Video]](https://video.newsserve.net/300/v/20210923/2109230920-Tropical-Depression-18-to-strengthen.jpg)
![Cool morning with slight storm chances Saturday [Video]](https://video.newsserve.net/300/v/20210918/2109181308-Cool-morning-with-slight-storm-chances-Saturday.jpg)
![Metro Detroit Forecast: Cooler and more comfortable [Video]](https://video.newsserve.net/300/v/20210915/2109150936-Metro-Detroit-Forecast-Cooler-and-more-comfortable.jpg)
