  Measurements of atmospheric winds in the mesoscale range (10-500 km) reveal
remarkably universal spectra with the $k^{-5/3}$ power law. Despite initial
expectations of the inverse energy cascade, as in two-dimensional (2D)
turbulence, measurements of the third velocity moment in atmosphere, suggested
a direct energy cascade. Here we propose a possible solution to this
controversy by accounting for the presence of a large-scale coherent flow, or a
spectral condensate. We present new experimental laboratory data and show that
the presence of a large-scale shear flow modifies the third-order velocity
moment in spectrally condensed 2D turbulence, making it, in some conditions,
similar to that observed in the atmosphere.
