How to predict the rainstorm in Aba, Sichuan, and what kind of meteorological conditions can form the rainstorm?

The forecast of rainstorm is made by the professional equipment of the National Meteorological Observatory, and the accuracy of the forecast result is hard to say. The accuracy rate in the United States can only reach 25%. Next, let's talk about heavy rain.

Rainstorms are usually caused by mesoscale weather systems. Rains with hourly rainfall exceeding 16 mm, or continuous rainfall exceeding 30 mm for 12 hours, or rainfall exceeding 50 mm for 24 hours are called "rainstorm". According to its precipitation intensity, it is divided into "rainstorm", "heavy rainstorm" and "extremely heavy rainstorm".

Generally speaking, the formation of rainstorm requires three conditions, namely, sufficient water vapor supply, strong vertical rising conditions and a certain precipitation duration. In the process of rainstorm forecast, forecasters need to fully consider these three conditions to judge the magnitude of rainstorm that may be formed during precipitation. Forecasters mainly rely on observation data and numerical models to forecast heavy rain. On this basis, forecasters judge and correct the forecast results through their own knowledge and experience.

Rainstorm forecast can't rely entirely on numerical forecast, so we must give full play to the subjective initiative of forecasters. Through the forecasting methods such as theoretical knowledge, experience, data and information mastered by forecasters, the numerical forecast results can be effectively corrected, or even changed when necessary, and the final forecast results may have less deviation and be closer to reality.

Let's talk about the formation of heavy rain. The formation process of rainstorm is quite complicated. Generally speaking, the main physical conditions of rainstorm are sufficient and continuous water vapor, strong and lasting upward movement of airflow and instability of atmospheric structure.

The water vapor of the rainstorm in China comes from the southerly South China Sea, the Bay of Bengal and the western Pacific Ocean. In addition, rivers and lakes are also one of the sources of water vapor.