In what season does hail often occur?

Hail often occurs in spring and summer.

Hail, as a strong convective weather, was born in a strong cumulonimbus cloud, which is also called hail cloud and can only be produced under the condition of unstable atmosphere. The weather gets warmer in spring and summer, and the sun bakes the earth very hot, which is easy to form unstable hot and humid air near the ground.

When there is weak cold air at high altitude, it is easy to cause strong convection in the air, and the hot and humid air rises rapidly, creating excellent conditions for the formation of hail. However, in winter, the temperature near the ground is very low, which can not produce strong and rapid updraft, so it is difficult to form hail in winter.

Spatial Pattern of Hail Disaster in China

1, hail disaster spread widely. Although the hail disaster is a small-scale disaster event, there are hail disasters in most areas of China, and almost all provinces have different degrees of hail disaster records. The number of counties affected by the disaster is close to half of the number of counties in China, which fully shows that hail disasters are widely distributed.

2. The distribution of hail disasters is discrete. Most hail falls in individual counties.

3. The local distribution of hail disaster is obvious. Hail disasters often occur in some specific areas, especially in the piedmont and agricultural areas east of the Qinghai-Tibet Plateau, which is closely related to the formation conditions of hail disasters.

4. The general distribution pattern of hail disasters in China is that there are many hail disasters in the central and eastern regions and few hail disasters in the western regions, and the spatial distribution presents a pattern of one area, two belts and seven centers. The first area refers to the area north of the Yangtze River, south of the Yanshan Line and east of the Qinghai-Tibet Plateau, which is a hail disaster-prone area in China. The two zones refer to the hail-prone zones on the outer edge of the first step (especially in the east) and the hail-prone zones on the eastern edge and east of the second step, which are hail-prone zones in China.

Seven centers refer to several hail-prone centers scattered in two hail-prone areas: Northeast High Value Area, North High Value Area, Hubei-Henan High Value Area, Nanling High Value Area, East Sichuan-West Hubei-West Hunan High Value Area, Gansu-East High Value Area and Kashi-Aksu High Value Area.