TRANSITION ZONE MOVEMENT OF TWO AIR MASSES When two air masses with different characteristics meet, they create a boundary known as a transition zone or front. This zone is marked by noticeable changes in weather conditions such as temperature, wind direction, pressure, and humidity. ° WARM AIR VS. COLD AIR: A lighter, warmer air mass tends to rise above the denser, colder air mass. This uplift often leads to the formation of clouds and precipitation. ° COLD FRONT: When a cold air mass moves int