How does the Meteorological Observatory forecast rainfall in advance?

Rainfall forecast is mainly calculated by numerical model, and then comprehensive forecast is made by objective methods such as ensemble forecast and statistical forecast.

Numerical weather forecast: it refers to the method of describing the weather evolution process by using equations of fluid mechanics and thermodynamics, and predicting the atmospheric motion state and weather phenomena in a certain period in the future by numerical calculation through a large computer under certain initial and boundary conditions.

Therefore, we usually use the meteorological data of the global observation network at 8: 00 a.m. and 8: 00 p.m. and input them into the computer as the initial conditions. The computer will automatically calculate the dynamic equation by numerical solution.