Cold, warm, stationary, occluded
Warm and Cold fronts
- Fronts can be cold, warm, stationary, or occluded. A warm front is defined as a collision where a warm air mass is replaces a cold air mass. Warm fronts usually move from southwest to northeast and the air behind a warm front is warmer and has more moister than the air ahead of it. When a warm front passes through, the air becomes warmer and more humid than it was before.
- A cold front is defined as a collision in which a cold air mass is replacing a warm air mass. Cold fronts generally move from northwest to southeast. The air behind a cold front is noticeably colder and is drier than the air ahead of it. When a cold front passes through, temperatures can drop 15 degrees or more in the first hour.
Occluded and Stationary fronts
- An occluded front occurs when two cold air mass move under a warm air mass and push it up. The two denser air masses may mix and cause colder temperatures below.
- A stationary front occurs when a warm front and a cold front collide, but neither has the force to push the other. Thunderstorms form and may last for days.
What are weather fronts?