雷暴与强对流临近天气预报技术进展

The advances in the nowcasting techniques on thunderstorms and severe convection

临近预报指0—6h(0—2h为重点)的高时空分辨率的天气预报,预报对象是该时段内出现明显变化的天气现象,主要包括雷暴、强对流、降水、冬季暴风雪、冻雨、沙尘暴、低能见度(雾)、天空云量等,其中,以雷暴和强对流天气的临近预报最具挑战性。综述了针对雷暴和强对流天气的以主观预报为主、结合客观算法的临近预报技术,同时讨论了高分辨率数值预报模式在临近预报中的应用。主观临近预报技术包括基于多普勒天气雷达观测数据并结合其他资料(常规高空和地面观测、气象卫星云图、快速同化循环的数值预报产品等)对雷暴生成、发展和衰减,特别是对强对流天气(包括强冰雹、龙卷、雷暴大风和对流性暴雨)的临近预报,客观算法包括几种应用最广的雷达回波或云图外推算法和强对流天气识别技术。高分辨率数值预报模式的应用包括与雷达回波外推融合延长临近预报时效,与各种观测资料融合得到快速更新的三维格点资料为雷暴和强对流近风暴环境的判断提供重要参考。

Nowcasting refers to the weather forecast of high spatial and temporal resolution in 0 - 6 hours （focusing on 0 - 2 hours） periods, and the main forecast target is the significant changing weather phenomena in the forecast period, including thunderstorms, severe convection, precipitation, winter snowstorms, visibility, sky cover, etc. The nowcasting of thunderstorms and severe convective weather is the most challenging in the above mentioned. In this paper, subjective nowcasting techniques and objective algorithm were been reviewed, and high-resolution numerical forecast models used in the nowcasting were been discussed. Subjective nowcasting techniques include the nowcasting of the formation, development and decay of a thunderstorm as well as severe convective weather （including large hail, tornadoes, thunderstorm winds, and convective rainstorm） based on Doppler weather radar observation data combined with other data such as satellite pictures, soundings, etc. The objective algorithm includes the most widely used several radar echo extrapolation and the severe convective weather detection technology. In addition, the application of high resolution numerical prediction models includes extending the nowcast time range by combining the NWP outputs with the radar echo extrapolation, and use of rapid updated cycle integrating model outputs and a variety of observational data to construct a rapid-updated three-dimensional grid data base for the basic meteorological parameters, which provides an important reference to judge thunderstorm and severe convective storm environments.