In 2019,the operational Global Regional Assimilation and Prediction System-Tropical Cyclone Model(GRAPES-TCM)was updated by adopting the characteristic parameters in the official real-time released TC data of CMA,intr...In 2019,the operational Global Regional Assimilation and Prediction System-Tropical Cyclone Model(GRAPES-TCM)was updated by adopting the characteristic parameters in the official real-time released TC data of CMA,introducing the horizontal sixth-order diffusion scheme and adjusting the operational flowchart.In the case of the Super Typhoon Lekima,the model exhibits a reliable prediction ability for the type of tropical cyclone(TC)with northwestern tracking.The track and intensity forecasts in 2019 are significantly better than those over the past five years on average.The updated model can provide a skillful forecast of landfall position and rapid weakening process.Moreover,the precipitation pattern is close to the observation.TC forecast in 2019 shows that the updated GRAPES-TCM has a smaller track error than that of the previous year,and the 24 h intensity forecasting ability is improved.展开更多
Based on the Global Regional Assimilation and Prediction System-Tropical Cyclone Model(GRAPES-TCM),an ensemble forecast experiment was performed,in which Typhoon Wipha during the period immediately prior to landfall w...Based on the Global Regional Assimilation and Prediction System-Tropical Cyclone Model(GRAPES-TCM),an ensemble forecast experiment was performed,in which Typhoon Wipha during the period immediately prior to landfall was selected for the study and the breeding of growing mode(BGM) method was used to perturb the initial conditions of the vortex field and the environment field.The results of the experiment indicate that each member had a different initial status in BGM processing and they show a reasonable spread among members along with the forecast phase.Changes in the large-scale field,thermodynamic structure,and spread among members took place when Wipha made landfall.The steering effect of the large-scale field and the interaction between the thermodynamics and the dynamics resulted in different tracks of the members.Meanwhile,the forecast uncertainty increased.In summary,the ensemble mean did not perform as well as the control forecast,but the cluster mean provided some useful information,and performed better than the control in some instances.The position error was 34 km for 24 h forecast,153 km for 48 h forecast,and 191 km for 66 h forecast.The strike probability chart qualitatively described the forecast uncertainty.展开更多
Tropical cyclones(TCs) Lionrock,Kompasu,and Namtheun were formed successively within 40 hours in 2010.Over the next several days afterwards,these TCs exhibited unusual movements which made operational prediction diffi...Tropical cyclones(TCs) Lionrock,Kompasu,and Namtheun were formed successively within 40 hours in 2010.Over the next several days afterwards,these TCs exhibited unusual movements which made operational prediction difficult.Verifications are performed on the forecasts of the tracks of these TCs with six operational models,including three global and three regional models.Results showed that the trends of TC tracks could be reproduced by these models,whereas trajectory turning points and landfall locations were not simulated effectively.The special track of Lionrock should be associated with its direct interaction with Namtheun,according to a conceptual model of binary TC interaction.By contrast,the relation between Kompasu and Namtheun satisfied the criteria for a semi-direct interaction.Numerical experiments based on the Global and Regional Assimilation and Prediction System-Tropical Cyclone forecast Model(GRAPES-TCM) further confirmed the effect of Namtheun on the unusual tracks of Lionrock and Kompasu.Finally,the physical mechanism of binary TC interaction was preliminarily proposed.展开更多
基金supported by the National Key Research and Development Program of China(Nos.2016YFE0109700 and 2017YFC150190X)the National Natural Science Foundation of China(Grant Nos.41975133 and 41975067)+1 种基金Science&Technology Committee of Shanghai(Nos.19dz1200101 and 19dz1201500)the National Defense Pre-Research Foundation(No.305090417)。
文摘In 2019,the operational Global Regional Assimilation and Prediction System-Tropical Cyclone Model(GRAPES-TCM)was updated by adopting the characteristic parameters in the official real-time released TC data of CMA,introducing the horizontal sixth-order diffusion scheme and adjusting the operational flowchart.In the case of the Super Typhoon Lekima,the model exhibits a reliable prediction ability for the type of tropical cyclone(TC)with northwestern tracking.The track and intensity forecasts in 2019 are significantly better than those over the past five years on average.The updated model can provide a skillful forecast of landfall position and rapid weakening process.Moreover,the precipitation pattern is close to the observation.TC forecast in 2019 shows that the updated GRAPES-TCM has a smaller track error than that of the previous year,and the 24 h intensity forecasting ability is improved.
基金National Basic Research Program of China (2009CB421500)Shanghai Science and Technology Program (10231203700)National Natural Science Foundation of China (40921160381)
文摘Based on the Global Regional Assimilation and Prediction System-Tropical Cyclone Model(GRAPES-TCM),an ensemble forecast experiment was performed,in which Typhoon Wipha during the period immediately prior to landfall was selected for the study and the breeding of growing mode(BGM) method was used to perturb the initial conditions of the vortex field and the environment field.The results of the experiment indicate that each member had a different initial status in BGM processing and they show a reasonable spread among members along with the forecast phase.Changes in the large-scale field,thermodynamic structure,and spread among members took place when Wipha made landfall.The steering effect of the large-scale field and the interaction between the thermodynamics and the dynamics resulted in different tracks of the members.Meanwhile,the forecast uncertainty increased.In summary,the ensemble mean did not perform as well as the control forecast,but the cluster mean provided some useful information,and performed better than the control in some instances.The position error was 34 km for 24 h forecast,153 km for 48 h forecast,and 191 km for 66 h forecast.The strike probability chart qualitatively described the forecast uncertainty.
基金"973"Project(2009CB421500,2013CB430305)National Natural Science Foundation of China(40921160381,40705024,40875039)+1 种基金Special Scientific Research Fund of Meteorological Public Welfare of China(GYHY201006007,GYHY201006008,GYHY201006016)Shanghai Typhoon Research Foundation(2010ST09)
文摘Tropical cyclones(TCs) Lionrock,Kompasu,and Namtheun were formed successively within 40 hours in 2010.Over the next several days afterwards,these TCs exhibited unusual movements which made operational prediction difficult.Verifications are performed on the forecasts of the tracks of these TCs with six operational models,including three global and three regional models.Results showed that the trends of TC tracks could be reproduced by these models,whereas trajectory turning points and landfall locations were not simulated effectively.The special track of Lionrock should be associated with its direct interaction with Namtheun,according to a conceptual model of binary TC interaction.By contrast,the relation between Kompasu and Namtheun satisfied the criteria for a semi-direct interaction.Numerical experiments based on the Global and Regional Assimilation and Prediction System-Tropical Cyclone forecast Model(GRAPES-TCM) further confirmed the effect of Namtheun on the unusual tracks of Lionrock and Kompasu.Finally,the physical mechanism of binary TC interaction was preliminarily proposed.
