Development and Real Time Application of Nonhydrostatic Mesoscale NWP System for Beijing Area

A big progress has been made on the development of the mesoscale numerical weather prediction (NWP) system for Beijing area, a joint project of National Meteorological Center (NMC) and Beijing Meteorological Bureau (BMB). The basin of the PSU/NCAR’s nonhydrostatic mesoscale model version 5 (MM 5), an experimental mesoscale NWP system for Beijing area (BJ-MM 5 V.1) was created, in which the model is two-way nested with 45 and 15 km horizontal resolution for coarse and fine mesh, respectively, and 23 σ layers in vertical; and it is run on the parallel environment of IBM/SP2 with 24 nodes for 36 h prediction, while 2 h and 20 min in computing time is able to meet the time requirement for real time operational application. The BJ-MM5 V. 1 is linked with the data resources of the NMC as well as the data set of intensive surface observation over Beijing area. And encouragingly, it was run stably in real time and its products were referenced by the weather office of BMB for weather forecasts during the whole summer of 1997. The verification results indicate that the model can predict reasonably the spatial and temporal distribution of precipitation.