A large scale (zonal wave number 1), westward-propagating disturbance present in the troposphere and the stratosphere in January 1979 is shown to be similar to a free Rossby wave. Its vertical and horizontal structures are reasonably consistent with those of a theoretically preidcted wave mode of the second class. It is similar to the so-called 16-day wave described earlier, and, therefore, not an unusual occurrence. It is argued that this traveling wave may be preferentially excited by random forcing and that it can interact with quasistationary waves forced by mountains and by heat sources. It is shown, for example, that this interaction can cause fluctuations in eddy heat transport throughout the atmosphere.