This paper describes the estimation of propagation loss and its statistical properties on the basis of observations of radar sea clutter data. This problem is solved by first finding an ensemble of relevant refractivity model parameters, and each refractivity model is weighted according to its data likelihood function. A parabolic equation propagation model is used both in mapping from environmental model to radar clutter data and also when mapping to propagation loss. Two different methods are then used for mapping from a statistical description of refractivity parameters to a statistical description of propagation loss. In the first approach, all of the sampled models explored in the inversion are used to give a statistical description of propagation loss. Alternatively, the environmental model is sampled from the probability for the refractivity model parameters and then mapped into propagation loss. This can be done efficiently if we are using the one-dimensional marginal distributions instead of the full distribution for the environmental parameters.