What are the common frontal systems?

Cold front, warm front, quasi-stationary front.

What are the characteristics:

1. A cold front is a front where cold air masses actively move towards warm air masses. Before the cold front passes, the weather is sunny, the temperature is high, and the air pressure is low. When it passes, it is cloudy, rainy, and windy. After it passes, the temperature drops, the air pressure rises, and the weather turns sunny. Cold front precipitation mainly occurs behind the front.

2. A warm front is a front formed by a warm air mass actively moving towards a cold air mass. Before the warm front passes, the weather is clear, the temperature is low, and the air pressure is high. During the passage of the warm front, continuous precipitation occurs. After the passage of the warm front, the temperature rises and the air pressure decreases. The weather becomes fine and warm frontal precipitation mainly occurs in front of the front.

3. When a cold air mass and a warm air mass meet, neither side has enough power to move the other side, and the front is relatively stationary, forming a quasi-stationary front. Quasi-stationary fronts often form continuous cloudy and precipitation weather.

The concept of frontal system

1. Air mass: A large area of ??air with a relatively uniform distribution of physical properties such as temperature and humidity in the horizontal direction is called an air mass. Air masses are divided into cold air masses and warm air masses.

2. Warm air mass: high temperature, high humidity, low air pressure. Under the control of a single warm air mass, sunny and warm weather will prevail.

3. Cold air mass: The temperature is low, the humidity is low, and the air pressure is high. Under the control of a single cold air mass, the weather is mainly sunny and cold.

4. Front: the interface between warm and cold air masses? Front: the line where the front intersects with the ground.

5. Front: The front and the front line are collectively called the front.