A Warm Front On The Weather Map
If you look at our weather map above you see a warm front extending from Iowa into the Great Lakes region.
What a warm front does is separate warm air from cool air.
On the north side of the front the temps will be about 15-20 degrees cooler than on the south side of the front.
The warm front is depicted on a weather map as having red half circles. The reason for using half circles it to show that advancing of the warm air from the south.
Winds ahead of the warm front are from the East slowly shifting to the Southeast.
After the front passes the area expect to see the winds shift to the South and further shift to the Southwest.
Ahead of the warm front most of the time you will find stratus clouds with showers and an isolated t-storm is possible. During the winter the thunderstorm may be responsible for Thunder snow.
Behind the front the weather turns warm and humid and more progressive t-storms begin to move into the area.
Warm fronts must extend from an area of Low pressure as you see in the map above.