What is a trough of low pressure and what is the weather like under its influence?

A weather system with high air pressure on three sides and low air pressure on one side is called a trough for short. The trough with low pressure is often accompanied by convergence and upward movement, which is easy to produce clouds and precipitation.

The part of the weather map where the center of low pressure extends outward, and the low pressure area that is slightly U-shaped or V-shaped (like a water tank, with low air pressure in the middle and high air pressure on both sides) is called low pressure trough.

The long and narrow area extending from the low-pressure area is called low-pressure trough, and the air pressure in the trough is lower than that on both sides. On the weather map. The trough of low pressure generally extends from north to south. The trough extending from south to north is called inverted trough, and the trough extending from east to west is called transverse trough. The low pressure trough extending from north to south is generally in the westerly airflow, the horizontal trough is at the intersection of the northeast airflow and the northwest airflow, and the inverted trough is in the easterly airflow. The connection line at the maximum bend of each isobar in the groove is called the groove line. In the middle and lower troposphere, the airflow near the trough of low pressure is in the form of convergence and rising, so it is easy to produce cyclone and other weather systems near the trough of low pressure, often accompanied by rain, snow, strong wind and cooling.