Abstract
This review consists of 5 sections. Section 1 summarizes the meaning of the pioneering work by L. F. Richardson. Section 2 discusses the basic role of the quasi-geostrophic theory. The nonlinear instability peculiar to the nonlinear system is also emphasized there. In Section 3, Arakawa's glorious work which broke through the difficult situation mentioned in Section 2 is emphasized and it is pointed out that most of the general circulation models were built by Japanese scientists. In Section 4 the present status of the numerical weather prediction is surveyed and problems in the future are discussed in Section 5.
