The environments of T Tauri stars are probably determined by the interaction of a stellar wind with matter which is falling toward a newly formed star. As shown by Ulrich, the steady infall of cool gas with angular momentum toward the star leads to a density distribution with rhoproportionalr/sup -1/2/ inside a radius r/sub d/ and rhoproportionalr/sup -3/2/ outside r/sub d/. The radius r/sub d/ is determined by the angular momentum of the infalling gas. The expansion of the wind into this medium depends on the parameter ..cap alpha.. = M/sub w/v/sub w//M/sub in/v/sub in/(r/sub d/), where v/sub in/(r/sub d/) is the free-fall velocity at r/sub d/, M/sub in/ is the mass accretion rate, v/sub w/ is the wind velocity, and M/sub w/ is the mass loss rate. For ..cap alpha..<1, the wind is trapped within r/sub d/, and for ..cap alpha..<1, the wind can expand into the cloud. It is likely that the cloud gas is clumpy and that clumps are present in the wind region. If the clumps have sufficiently high surface densities, they fall toward the star. The interaction of the wind with the clumps can ionize the wind gas. This model is applied to T Tauri,more » and the resulting parameters are r/sub d/ = 10/sup 14/ cm, v/sub w/ = 150 km s/sup -1/, M/sub in/ = 10/sup -7/ M/sub sun/ yr/sup -1/, and M/sub w/ = 3 x 10/sup -8/ M/sub sun/ yr/sup -1/. The inflow is clumpy. The shocked wind gives the radio emission and nebular emission from T Tauri, and dust within the clumps gives the infrared emission. T Tauri is in a transitory phase in which most of the wind has only recently propagated beyond r/sub d/. The model naturally predicts variable obscuration of T Tauri stars because the infalling clumps move on nonradial trajectories. The infrared emission can vary either because of structural changes in the circumstellar gas or because of variations in the stellar luminosity. Infrared variability should be small at short time scales because of light-travel time effects.« less