Implications from Subseasonal Prediction Skills of the Prolonged Heavy Snow Event over Southern China in Early 2008  

作　　者：Keyue ZHANG Juan LI Zhiwei ZHU Tim LI 

机构地区：[1]Key Laboratory of Meteorological Disaster,Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD),Nanjing University of Information Science and Technology,Nanjing 210044,China [2]State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics(LASG),Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China [3]International Pacific Research Center and Department of Atmospheric Sciences,University of Hawaii at Manoa,Honolulu 96822,Hawaii

出　　处：《Advances in Atmospheric Sciences》2021年第11期1873-1888,共16页大气科学进展（英文版）

基　　金：The authors greatly appreciate the professional and earnest review made by the anonymous reviewers which for sure improved the quality of our manuscript.This work was supported by the National Key R&D Program of China(Grant Nos.2018YFC1505905&2018YFC1505803);the National Natural Science Foundation of China(Grant Nos.42088101,41805048 and 41875069);Tim LI was supported by NSF AGS-1643297 and NOAA Grant NA18OAR4310298.

摘　　要：An exceptionally prolonged heavy snow event(PHSE)occurred in southern China from 10 January to 3 February 2008,which caused considerable economic losses and many casualties.To what extent any dynamical model can predict such an extreme event is crucial for disaster prevention and mitigation.Here,we found the three S2S models(ECMWF,CMA1.0 and CMA2.0)can predict the distribution and intensity of precipitation and surface air temperature(SAT)associated with the PHSE at 10-day lead and 10−15-day lead,respectively.The success is attributed to the models’capability in forecasting the evolution of two important low-frequency systems in the tropics and mid-latitudes[the persistent Siberian High and the suppressed phase of the Madden−Julian Oscillation(MJO)],especially in the ECMWF model.However,beyond the 15-day lead,the three models show almost no skill in forecasting this PHSE.The bias in capturing the two critical circulation systems is responsible for the low skill in forecasting the 2008 PHSE beyond the 15-day lead.On one hand,the models cannot reproduce the persistence of the Siberian High,which results in the underestimation of negative SAT anomalies over southern China.On the other hand,the models cannot accurately capture the suppressed convection of the MJO,leading to weak anomalous southerly and moisture transport,and therefore the underestimation of precipitation over southern China.The Singular Value Decomposition(SVD)analyses between the critical circulation systems and SAT/precipitation over southern China shows a robust historical relation,indicating the fidelity of the predictability sources for both regular events and extreme events(e.g.,the 2008 PHSE).

关 键 词：prolonged heavy snow event S2S prediction models subseasonal prediction skill MJO Siberian High 

分 类 号：P45[天文地球—大气科学及气象学]