The transport of material between the troposphere and the stratosphere is studied with an off-line chemical transport model which uses winds from a global assimilated meteorological data set. The focus is on the role of rapidly growing synoptic waves in the maintenance of lower stratospheric tracer distributions in the extratropics. Satellite observations are used to establish that the modeled transport represents the observed tracer variability with sufficient accuracy to justify more quantitative analysis. Diabatic trajectory calculations are then used to understand the transport mechanisms in the model. Two rapidly developing surface cyclones are specifically studied and found to have qualitatively different impact on the tracer distribution. A strong storm in the Pacific Ocean perturbs the tropopause region, and because it remains relatively stationary, ultimately has transport characteristics similar to a cutoff low. The explosively developing synoptic wave responsible for the March 1993 blizzard in the eastern United States causes large-scale transport between the troposphere and stratosphere. There are two notable characteristics of the transport associated with the U.S. blizzard: (1) The U.S. blizzard moves across many degrees of latitude. This storm develops in the subtropics, with a high tropopause, and later decays in a subpolar environment where the tropopause is naturally much lower. (2) Diabatic processes are crucial to the long-range transport and ultimate transfer of mass to the stratosphere. The transport studied in connection with the United States requires consideration of the entire life cycle of the storm from subtropical cyclogenesis to subpolar decay. The fact that storms that are similar to the U.S. blizzard are quite common and that the transport is consistent with available tracer observations suggest that the large-scale transport of air from the troposphere to the stratosphere is plausible. Further investigation with more sophisticated models and tracer observations is needed to verify the importance of the modeled transport.¿ 1997 American Geophysical Union