The National Severe Storm Laboratory's dual Doppler weather radars map clear air planetary boundary layer winds using only the intrinsic scatterers of the medium. Perturbation winds have correlation lengths of a few kilometers on this day of moderate shear and advect with the mean wind. The structure function of wind shows good agreement with the two thirds law of turbulence theory. Reflectivity has a cellular structure with weak echo interiors. Independently measured reflectivity fields have correlations as large as 0.86.