Weather Fronts

Front: boundaries of air masses Differ by temperature, density, and humidity

• The weather we experience depends on which front is dominant 
• Fronts bring precipitation

A cold front forms when cold air moves under warm air. Since the warm air is less dense the cold air pushes the warm air up. Cold fronts can and usually do produce thunderstorms. They are usually followed by colder and drier air.

A Warm Front forms when warm air moves over colder denser air and gradually replaces the colder air. Warm Fronts generally bring rain and are followed by clear and warm weather.

A Stationary Front occurs when a cold air mass and a warm air mass meets but neither have the force to push the warm air mass up over the cold air mass. The two air masses remain seperate creating a Stationary Front. A Stationary Front usually creates several days of rainy weather.

^{An Occluded Front forms when a warm air mass is caught between two colder air masses. The cold air mass moves under the warm air mass and pushes it up. The coldest air mass moves forward until it meets a cold air mass that is warmer and less dense. The coldest of these two air masses moves under and pushes up the warm air mass. Sometimes the two cold air masses meet together and mix. This Front bring lots of rain and snow.}