The current development of weather forecast technigue in the United States was presented. It is suggested that it is the technological development of the atmospheric probing,the numerical weather forecast and the visualization that impels the conventional weather forecast in the United States toward quantization and timing. The realization of quantitative precipitation forecast is an important mark of qualitative toward the quantitative weather forecast. On the basis of making the best use of the numerical model products,composing satellite and radar data,the method of the objective forecast is established. It makes a good effect on the forecasts of heavy rain and severe convective weather. The advancing of mesoanalysis of operational forecast system improves obviously the forecasting skill of precipitation. The interpretation of numerical weather forecast product and the operational forecast system in the United States are presented. Finally,the inspirations drawn for China's weather forecasts have been put forward.