Steps of sandstorm occurrence

Sandstorm is a weather phenomenon that strong winds blow up a lot of dust on the ground, making the air very turbid and the horizontal visibility less than 1 km. Strong sandstorm is a weather phenomenon that strong winds blow up dust on the ground, making the air fuzzy and turbid, and the horizontal visibility is less than 500 meters.

Sandstorm weather process: in the same weather process, sandstorms occurred in three or more countries in China's weather forecast area at the same observation time;

Strong sandstorm weather process: In the same weather process, more than three countries in China's weather forecast area basically (quasi) stand at the same observation time and have strong sandstorms.

Extended data:

Weather causes of sandstorm:

The weather situation favorable to strong winds or strong winds, favorable distribution of dust sources and favorable air instability conditions are the main reasons for the formation of sandstorms or strong sandstorms. Strong wind is the driving force of sandstorm, and the source of sandstorm is the material basis of sandstorm. Unstable thermal conditions are conducive to the increase of wind power and the development of strong convection, thus carrying more dust and winding it higher.

In addition, drought and lack of rain in the early stage, warming weather and rising temperature are the special weather and climate background for the formation of sandstorms; The convective cells before the ground cold front develop into clouds or squall lines, which is a small and medium-sized system conducive to the development and strengthening of sandstorms. The topographic condition conducive to the increase of wind speed, that is, the narrow tube effect, is one of the favorable conditions for the formation of sandstorms.