Answer:
The map displays a "cold front."
Step-by-step explanation:
A cold front is the boundary zone where a cold air mass is pushing and replacing a warmer air mass. On a weather map, a cold front is usually represented by a solid line with triangular pips pointing in the direction of its movement.
From the image you've provided, the red line with triangular pips is pointing southeastward, indicating the direction in which the cold air is advancing. When a cold front moves through an area, it can bring a rapid temperature drop, along with potential precipitation and a shift in wind direction.
In your map, the cold front appears to be stretching from around Milwaukee and moving southeast towards Detroit and Toledo. The associated cloud cover and potential precipitation can be seen ahead of and along the front, which is typical for cold fronts as they tend to lift the warmer, moist air ahead of them, leading to cloud formation and often rain or storms.