The following information is from: Snowfall-driven mass change on the East Antarctic ice sheet. Geophysical Research Letters 39: 10.1029/2012gL053316; by Boening, C., Lebsock, M., Landerer, F. and Stephens, G. 2012.
".... an improved understanding of processes dominating the sensitive balance between mass loss primarily due to glacial discharge and mass gain through precipitation is essential for determining the future behavior of the Antarctic ice sheet and its contribution to sea level rise." They also "... describe the causes and magnitude of recent extreme precipitation events along the East Antarctic coast that led to significant regional mass accumulations that partially compensate for some of the recent global ice mass losses that contribute to global sea level rise."
Furthermore, they note ".... an abrupt mass increase in East Antarctica along the coast of Dronning Maud Land in the GRACE satellite data in 2009-2011," which they were pointed to by their study of precipitation data derived from CloudSat and ERA Interim re-analysis products [Dee et al., 2011] that showed the mass increase to have been caused by "anomalously high precipitation events during the Southern Hemisphere winter." And this gain of "almost 350 Gt from 2009 to 2011," as they describe it, "is equivalent to a decrease in global mean sea level at a rate of 0.32 mm per year."
In further analyzing the precipitation data, Boening et al. found that "the mass gain primarily occurred during May of 2009 and June of 2011," and they said that "most of the accumulation in these months resulted from snowfall from only a few main events," while additionally noting that the primary drivers of the observed mass increase were "prolonged changes in pressure patterns and induced poleward wind in the two years."
Dee, D.P., Uppala, S.M., Simmons, A.J., Berrisford, P., Poli, P., Kobayashi, S., Andrae, U., Balmaseda, M.A., Balsamo, G., Bauer, P., Bechtold, P., Beljaars, A.C.M., van de Berg, L., Bidlot, J., Bormann, N., Delsol, C., Dragani, R., Fuentes, M., Geer, A.J., Haimberger, L., Healy, S.B., Hersbach, H., Holm, E.V., Isaksen, L., Kallberg, P., Kohler, M., Matricardi, M., McNally, A.P., Monge-Sanz, B.M., Morcrette, J.-J., Park, B.-K., Peubey, C., de Rosnay, P., Tavolato, C., Thepaut, J.-N. and Vitart, F. 2011. The ERA-Interim reanalysis: Configuration and performance of the data assimilation system. Quarterly Journal of the Royal Meteorological Society 137: 553-597.
As such heavy snow falls in the East Antarctic (which mask SLR) are uncommon, and may not occur for a long time; it is possible that we may now, or may soon, be seeing an acceleration in observed SLR.