Near the earth's surface, areas of low pressure not only have counterclockwise winds in our hemisphere, but the air converges or comes together toward the low's center. This results in a rising air motion. A good example would be splashing your hands together in a bathtub. Since the water can't go down, it gets pushed upward. This is one of the reasons almost all low pressure systems, including the hurricane produce precipitation.
Frontal systems are zones that separate airmasses of different temperatures.
When a cold or warm front is close to Wisconsin this temperature difference results in an airflow rising above the colder, denser air that remains near the ground. This rising motion often results in steady rain or snow ahead of warm fronts, and showers and possible thunderstorms ahead of cold fronts. Weather forecasters are always evaluating the types of up or down air motions in our atmosphere. TMJ4 is not responsible for the content of external sites links through our site.