Temporal variations in predictability

Those characteristics which most significantly contribute to temporal variations in error growth are presently examined in light of a large ensemble of predictability runs conducted in the course of a long equilibrium run in a two-level, nonlinear, quasi-geostrophic model which incorporates orography. In the error spectrum thus developed, all scales grow with a similar doubling time until saturation is first reached at the smallest scales. Due to a lag relationship between equilibrium kinetic energy and available potential energy, it is possible to marginally predict times of small and large error growth.