Measurements have been made of acoustic back-scattering intensity for the vertical and tilted sodar antennae in the convective atmosphere as a function of both zenith and azimuth. Variations in back-scattered intensity have been seen as observed earlier for nocturnal stable conditions. Small-scale anisotropic inhomogeneities in the turbulent thermal structure of the atmospheric boundary layer are considered to be reponsible for the observed anomalous behaviour in acoustic back-scattering.