Abstract:The East Asain summer monsoon was stronger in 2012, though the Tibetan Plateau (TP) snow cover extent was anomalously larger than the climate mean in the preceding spring and winter, which is inconsistent with the results of previous studies. This paper made an effort to investigate the possible relationship between the TP snow cover from winter 2011 to spring 2012 and the following Asian summer monsoon, using the monthly mean snow cover extent data from Rutgers University Global Snow Lab, NCEP/NCAR reanalysis monthly average data, and the monthly data set of NOAA’s Precipitation Reconstruction over Land (PREC/L). The findings suggest that the TP was covered mainly by an anomalous cyclone with lower temperature in the mid troposphere in spring 2012 and the previous winter, which agreed with the features of larger snow cover years. Particularly to the west of 90°E, the mid tropospheric temperature anomalies from the TP to the tropical Indian Ocean were negative in the north and positive in the south from winter to spring, conducive to the weaker meridional temperature gradient there in summer and thus to the weaker South Aisan summer monsoon. However, to the east of 90°E, the mid tropospheric temperature anomalies from East Asia to the tropics were positive in the north and negative in the south in winter and spring, favorable for the earlier seasonal transition from winter to summer in the southeastern Asia, the earlier onset of the South China Sea summer monsoon, and also the stronger East Asian summer monsoon. They were more influenced by other forcings than the TP. Therefore, the fact of more TP snow cover from winter 2011 to spring 2012 probably made a significant contribution to the following weaker South Asian summer monsoon, and had less impact on the East Asian summer monsoon in 2012.