Ⅰ. INTRODUCTION In the past years, the attention of many meteorologists has been attracted to the Presidents’ Day snow storm, February 18—19, 1979, not only because of its rareness but also the failure of the opera...Ⅰ. INTRODUCTION In the past years, the attention of many meteorologists has been attracted to the Presidents’ Day snow storm, February 18—19, 1979, not only because of its rareness but also the failure of the operational model (LFM-Ⅱ) of NMC. On February 18—19, 1979, an intensive cyclone developed along the middle Atlantic coast brought about heavy snowfall (45—60 cm) over the middle Atlantic states, from Virginia to southern New Jersey. Regional snowfall rates of 25 mm per hour were common,and local intensities of 100 mm per hour were observed in Washington, D. C. area,展开更多
The limited area 5-level primitive equation model,as the first operational precipitation forecast model in China,has been run at Beijing (National) Meteorological Center (BMC) for more than four years.The opera- tiona...The limited area 5-level primitive equation model,as the first operational precipitation forecast model in China,has been run at Beijing (National) Meteorological Center (BMC) for more than four years.The opera- tional results show that this model gives continuous services,and the forecast skill is satisfied for the forecast of some weather situations,such as extratropical cyclone,front and the precipitation associated with them. The forecast guides are widely used at the local weather services now.展开更多
Significant progress has been made on the development of mesoscale numerical weather prediction (NWP)system for Beijing area,as a joint project of the National Meteorological Center(NMC)and the Beijing Meteorological ...Significant progress has been made on the development of mesoscale numerical weather prediction (NWP)system for Beijing area,as a joint project of the National Meteorological Center(NMC)and the Beijing Meteorological Bureau(BMB).On the basis of the non-hydrostatic mesoscale model PSU/ NCAR MM5,a mesoscale NWP system for Beijing area(BJ-MM5V.1)has been developed on the computer IBM/SP2 MPP with 24 nodes at NMC.As a two-way nested grid model two grids are chosen with 45 and 15km grid length respectively,and 23 levels in the vertical.It takes 2 hours and 20 minutes to make a 36h forecast,which satisfies the time requirement for the operational use.In addition to the routine data received from GTS at NMC,the enhanced observations over Beijing region are used for the objective analyses.This system was put into semi-operational use during the summer of 1997 to test its performance.The forecast products,hourly rainfalls and all of the meteorological elements needed,are provided to the forecasters at BMB for use.It is identified from the test results that the system is robust and has pretty good ability to forecast the spatial and temporal distribution of the precipitation for the local heavy rainfalls.展开更多
文摘Ⅰ. INTRODUCTION In the past years, the attention of many meteorologists has been attracted to the Presidents’ Day snow storm, February 18—19, 1979, not only because of its rareness but also the failure of the operational model (LFM-Ⅱ) of NMC. On February 18—19, 1979, an intensive cyclone developed along the middle Atlantic coast brought about heavy snowfall (45—60 cm) over the middle Atlantic states, from Virginia to southern New Jersey. Regional snowfall rates of 25 mm per hour were common,and local intensities of 100 mm per hour were observed in Washington, D. C. area,
文摘The limited area 5-level primitive equation model,as the first operational precipitation forecast model in China,has been run at Beijing (National) Meteorological Center (BMC) for more than four years.The opera- tional results show that this model gives continuous services,and the forecast skill is satisfied for the forecast of some weather situations,such as extratropical cyclone,front and the precipitation associated with them. The forecast guides are widely used at the local weather services now.
文摘Significant progress has been made on the development of mesoscale numerical weather prediction (NWP)system for Beijing area,as a joint project of the National Meteorological Center(NMC)and the Beijing Meteorological Bureau(BMB).On the basis of the non-hydrostatic mesoscale model PSU/ NCAR MM5,a mesoscale NWP system for Beijing area(BJ-MM5V.1)has been developed on the computer IBM/SP2 MPP with 24 nodes at NMC.As a two-way nested grid model two grids are chosen with 45 and 15km grid length respectively,and 23 levels in the vertical.It takes 2 hours and 20 minutes to make a 36h forecast,which satisfies the time requirement for the operational use.In addition to the routine data received from GTS at NMC,the enhanced observations over Beijing region are used for the objective analyses.This system was put into semi-operational use during the summer of 1997 to test its performance.The forecast products,hourly rainfalls and all of the meteorological elements needed,are provided to the forecasters at BMB for use.It is identified from the test results that the system is robust and has pretty good ability to forecast the spatial and temporal distribution of the precipitation for the local heavy rainfalls.
