Research on wind and rain forecasts in Guangxi based on the ensemble forecast optimization technique for typhoon track revision
Based on the ECMWF global ensemble forecast data and the best track dataset of the Tropical Cyclone Data Center of the CMA from 2017-2019,this paper proposed a real-time revision technology for the forecasting of the tracks of typhoons affecting Guangxi by using statistical analysis and the ensemble forecast release technique.By selecting the optimal N ensemble forecast members with smaller errors,the revised typhoon track products,the typhoon probability-matching average precipitation products,and the the synthetic analysis products for typhoon gales are generated.The results showed that the use of the arithmetic average model of the preferred members to forecast the typhoon tracks shows improvement over the ensemble average forecast and the deterministic forecast.The longer the forecast time is,the more obvious the improvement effect is.The errors of typhoon track forecast for 24 h and 48 h are reduced by 4 km and 6 km compared with the ensemble average,and by 5 km and 19 km compared with the deterministic forecast.The optimal selection of probability-matching average precipitation products of ensemble members can improve the traditional ensemble mean precipitation products to a certain extent,especially for the prediction of heavy rainstorm,and the TS scores of 36 h and 60 h time of heavy rainstorm are improved by 10% and 12% compared with the ensemble average.The optimized gale synthesis analysis products of the ensemble members can forecast the movement,strengthening and weakening of the extreme wind area during the impact of typhoons,improving the TS scores of the strong wind exceeding level 6,7 and 8 at the 36 h timescale by 18.3%,15.7% and 13.4% compared with the ensemble average products,and having some forecasting ability for the strong wind above level 9 to 11 or higher.
typhoon trackensemble forecastingprobability-matching mean precipitation product
万方数据
维普
