Application of the frequency-matching method in the probability forecast of landfalling typhoon rainfall
频率匹配法在登陆台风降雨概率预报中的应用
上陸台風降雨の確率予報における周波数整合法の適用
태풍 상륙 확률예보에 빈도정합기법 적용
Aplicación del método de coincidencia de frecuencias en el pronóstico de probabilidad de precipitaciones de tifones que tocan tierra
Application de la méthode d'appariement des fréquences dans la prévision de la probabilité des pluies de typhons touchant les terres
Применение метода согласования частот в вероятностном прогнозе выпадающих на сушу тайфунов
Rong GUO 郭蓉, Hui YU 余晖, Zifeng YU 喻自凤, Jie TANG 汤杰, Lina BAI 白莉娜
Shanghai Typhoon Institute, and Key Laboratory of Numerical Modeling for Tropical Cyclone of China Meteorological Administration, Shanghai 200030, China
中国 上海 中国气象局上海台风研究所 台风数值预报重点实验室
In this paper, a revised method for typhoon precipitation probability forecast, based on the frequency-matching method, is developed by combining the screening and the neighborhood methods. The frequency of the high-resolution precipitation forecasts is used as the reference frequency, and the frequency of the low-resolution ensemble forecasts is used as the forecast frequency.
Based on frequency–matching method, the frequency of rainfall above the rainstorm magnitude increases. The forecast members are then selected by using the typhoon tracks of the short-term predictions, and the precipitation probability is calculated for each member using a combination of the neighbor and the traditional probability statistical methods. Moreover, four landfalling typhoons (i.e., STY Lekima and STS Bailu in 2019, and TY Hagupit and Higos in 2020) were chose to test the rainfall probability forecast.
The results show that the method performs well with respect to the forecast rainfall area and magnitude for the four typhoons. The Brier and Brier skill scores are almost entirely positive for the probability forecast of 0.1–250 mm rainfall during Bailu, Hagupit and Higos (except for 0.1mm of Hagupit), and for<100 mm rainfall (except for 25 mm) during Lekima.
