Based on the observed winter snowfall data of Weihai,Shandong Province and NCEP/NCAR reanalysis data during 1966—2005,this paper studies the spatial and temporal distributions of winter snowfall,and the climate background of persistence snowstorm event in Weihai City in December 2005.The results reveal that the winter snowfall is excessive in North and few in South Weihai City,and the snowfall and the day numbers of snowstorm in December are significantly more than those in other months.The climate background in December 2005 is closely similar to that in the more snowfall years of Weihai in December.In the more snowfall years,the meridional circulation lies in northeast Asia with obvious negative centers of 500 hPa height and 850 hPa temperature anomalies locating in Northeast China,Yellow Sea,and sea areas from Bohai Sea to Japan Sea,where there are cyclonic wind anomalies at 1 000 hPa.In the above mentioned areas,the element anomalies in December 2005 are much more robust than those in heavy snowfall years.Moreover,Yellow Sea and Bohai Sea in the last ten-day period of November 2005 is much warmer than the normal,which provides sufficient energy for the atmosphere and results in the instability of atmospheric boundary layer.The terrain uplifting in Shandong Peninsula and the convergence of land-sea breeze and environmental wind in the northern coast directly result in the unstable energy release and the continuous heavy snowfall in Weihai city.