  The efficiency of the management of top-class ground-based astronomical
facilities supported by Adaptive Optics (AO) relies on our ability to forecast
the optical turbulence (OT) and a set of relevant atmospheric parameters.
Indeed, in spite of the fact that the AO is able to achieve, at present,
excellent levels of wavefront corrections (a Strehl Ratio up to 90% in H band),
its performances strongly depend on the atmospheric conditions. Knowing in
advance the turbulence conditions allows an optimization of the AO use. It has
already been proven that it is possible to provide reliable forecasts of the
optical turbulence (CN2 profiles and integrated astroclimatic parameters such
as seeing, isoplanantic angle, wavefront coherence time, ...) for the next
night. In this paper we prove that it is possible to improve the forecast
performances on shorter time scales (order of one or two hours) with consistent
gains (order of 2 to 8) using filtering techniques. This has permitted us to
achieve forecasts accuracies never obtained before and reach a fundamental
milestone for the astronomical applications. The time scale of one or two hours
is the most critical one for an efficient management of the ground-based
telescopes supported by AO. Results shown here open, therefore, to an important
revolution in the field. We implemented this method in the operational forecast
system of the Large Binocular Telescope, named ALTA Center that is, at our
knowledge, the first operational system providing forecasts of turbulence and
atmospheric parameters at short time scales to support science operations.
