The effect of stochastic fluctuations in the zonal-mean velocity field on t
he energy dispersion of planetary stationary waves is considered, using the
nondivergent, barotropic vorticity equation. It is found that for small no
ise levels, the oscillatory structure of the solutions is not altered. Howe
ver, for noise levels comparable to or larger than those observed in the ci
rculation at 500 mb, the marginal density functions of the solution process
in the subpolar region cluster near zero. This indicates that fluctuations
in the velocity field inhibit the poleward dispersion of stationary wave e
nergy. This localization phenomenon appears whether the ensemble average of
the mean zonal flow is superrotation or has a simple two-jet structure.