  Atmospheric turbulence is the one of the major limiting factors for
ground-based astronomical observations. In this paper, the problem of
short-term forecasting seeing is discussed. The real data that were obtained by
atmospheric optical turbulence (OT) measurements above Mount Shatdzhatmaz in
2007--2013 have been analysed. Linear auto-regressive integrated moving average
(ARIMA) models are used for the forecasting. A new procedure for forecasting
the image characteristics of direct astronomical observations (central image
intensity, full width at half maximum, radius encircling 80% of the energy) has
been proposed. Probability density functions of the forecast of these
quantities are 1.5--2 times thinner than the respective unconditional
probability density functions. Overall, this study found that the described
technique could adequately describe temporal stochastic variations of the OT
power.
