Protip: an EWMA is a smoothing convolution whose deconvolution can be computed in closed form with a little algebra. To reduce the effects of noise, apply the

Protip: an EWMA is a smoothing convolution whose deconvolution can be computed in closed form with a little algebra. To reduce the effects of noise, apply the EWMA, then use a forecasting method of your choice to predict the smoothed series, and finally apply the deconvolution to recover the original series. This technique can be useful for series with strong seasonality, where some of what may appear to be noise is actually useful signal, but signal which arrived slightly ahead or behind schedule within the season.