The invention relates to the technical field of meteorological monitoring, and discloses a rainfall early warning method and
system based on a
weather radar, and the method comprises the steps: obtaining
weather radar body sweeping arrival base data and rainfall
station observation data, carrying out the alignment, carrying out the meshing of the
radar base data, and obtaining the grid echo data; constructing a quasi-vertical profile to determine the height range and uncertainty of the
melting layer, and carrying out weighted bright band correction on echoes in the
melting layer to obtain corrected echo data; determining rainfall type partitions and performing inversion to obtain a
radar rainfall intensity field; according to the rainfall
station data and the
radar rainfall intensity field,
station residual data is obtained, a space deviation field is obtained, and finally a calibration rainfall intensity field is obtained; determining an accumulated
precipitation field of each member according to the calibrated rainfall field; and obtaining an over-
threshold probability published by early warning according to the accumulated
precipitation field of each member, and outputting
precipitation early warning information when a probability threshold is continuously met. According to the invention, the rainfall intensity overestimation and
false alarm jitter are reduced, and the accuracy and stability of short temporary rainfall early warning are improved.