Impact of the Preceding Northern Himisphere 500hPa Geopotential Height and Pacific SST Variation on the Winter Freezing Rain over Guizhou Province

Based on the 84- station freezing rain- day over Guizhou in winter from 1962 to 2008,the preceding height field of 500 h Pa,and SST field of Pacific Ocean,and the three factors optimum subset regression,the impacts are composed by500 h Pa height field and Pacific SST field,and freezing rain field in winter is studied. The results indicate clearly that:(1) The correlation between preceding 500 h Pa height- Pacific SST and winter freezing rain- day is better than that of between500 h Pa height and freezing rain- day or between Pacific SST and freezing rain- day field over Guizhou.(2) In general,as far as predictors are concerned,the optimum time stages of being possessed of practice prediction significance are from preceding April to July.(3) There is an apparent phenomenon that correlation of the cross quarter is good.(4) The early predictors of affecting winter freezing rain- day over Guizhou mainly focus on key regions,as well as near the warm pool northeastern North America and other regions,which have importance significance of the weather climate.