NRSM短期气候模式对温州台汛期预测能力检验(Ⅰ):月和季降水检验

利用NRSM短期气候模式对台风重灾区浙江省温州市的台汛期(7-9月)的短期气候的要素──月和季降水量进行预测。结果发现,模式形势场的预报与实况场有很好的对应,形势场有很高的利用价值;模式对极端天气预报效果好,模式对预报的第1个月特涝准确率较高,对涝的预测能力较强;对第2、3月的特旱预报准确率较高,对旱的预测能力强;模式对各地7～9月份台汛期旱涝趋势准确率可达50%～70%;但模式还存在一些不足有待改进。

The NMC Nested Regional Spectral Model for Wenzhou Rainstorm Prediction During the Seasons of Typhoon

A regional spectral model based on nested primitive equations is developed. The model consists of two components-a low-resolution global spectral model and a high-resolution regional spectral model with identical vertical structure and physical processes. The global model is a low-resolution version of the operational global spectral model of the National Meteorological Center (NMC) of the United States, using spherical harmonics as horizontal basis functions. The primitive equations in the regional spectral model are based on a stereographic projection, with sine-cosine series as horizontal basis functions. The regional component can predict deviations from the forecast of the global model component, as first proposed by Hoyer. A semi-implicit time scheme, time filtering, initialization, and horizontal diffusion are applied to these deviations in the regional domain. With the NRSM, the Wenzhou rainstorm during seasons of typhoon is studied and some valuable sections are obtained and used for typhoon forecasting.