How is the severe convective weather forecast realized? Where is the difficulty of accurate prediction?

How is the severe convective weather forecast realized? Where is the difficulty of accurate prediction? Strong convective weather refers to sudden weather, bad weather, extremely destructive, often accompanied by thunderstorms, hail, tornadoes, local heavy rain and so on. Strong disastrous weather and remarkable anti-injury ability. Strong convective weather develops faster, excellent weather develops faster, and the most difficult forecast of all weather types is almost recognized forecast. So why is strong convection so difficult to predict? What is the current level of severe convective forecasting in China? China's severe convective weather forecast business mainly started in 2009, which can forecast short-term heavy precipitation, lightning, hail, thunderstorm and strong wind. Short-term approach to precipitation, the probability of rainstorm and so on, China's forecast variables have accumulated some experience in this respect, and their forecast accuracy is also very high.

From the technical point of view, the advanced numerical forecasting model is gradually useful, and the Doppler weather radar network is gradually improved, which provides the best forecasting method and means for short-term forecasting and the closest strong convective weather forecast. At present, China has established a digital weather forecasting business system consisting of national media weather forecasting model, moderate numerical weather forecasting model, global ensemble forecasting system, tropical cyclone path numerical forecasting model and sandstorm nutrition model. And developed a good forecasting system and short-term method for disaster weather, that is, 30% short-term intensity precipitation.

Tornadoes are coming in a hurry, and the duration is very short. China has not yet made a commercial forecast. From the mechanism point of view, it is mainly because the weather system that directly causes this strong convection belongs to small and medium-sized systems. According to the spatial scale of the system, large banded weather systems are above 100 km, small storms are only above 10 km, or even several kilometers, and tornadoes range from tens of meters to hundreds of meters, which makes it difficult to become routine meteorological observations. From the time scale, powerful weather systems can last for several hours to more than ten hours, and some weather systems last for several minutes or even several minutes, with serious changes; At the same time, modern weather science has not fully understood the physical method of this weather system, and the simulation of its remaining changes can only be approximate.

When the layers in the atmosphere are unstable, it is easy to produce strong convection, potential difference between clouds, and sometimes lightning and dazzling lightning cut through the sky, so thunderstorm weather is always related to powerful rain clouds. Due to the high temperature and large evaporation in summer, water raises a lot of water and cools into clouds; The cooler air in the upper layer will be reduced, and the heat will continue to heat up after heating, and so on, forming a big bucket of rain clouds. Rain clouds will produce short-term heavy precipitation. Its formation conditions need more water vapor conditions than thunderstorms. Hail is a kind of hard spherical, conical or irregular solid precipitation, which falls from the rain clouds where thunderstorms occur. It usually occurs in spring and summer, and usually produces systematic precyclones or tropical cyclones, as well as some of them. To produce a hailstorm of10cm, there must be an updraft of 50m/s, and rain clouds of thunderstorms generally rise by10m per second. It is stronger than the airflow enhancement required by short-term heavy precipitation.