Abstract : 3N.17
Weather Service for the XX Olympic Winter Games: forecast evaluation

Elena Oberto, Daniele Cane, Marco Turco, Paolo Bertolotto
Regional Agency for Environmental Protection Arpa Piemonte

The XX Olympic Winter Games of Torino 2006 were a challenge not only for the athletes participating to the competitions, but also for Arpa Piemonte, provider for the weather service: the Olympic Area was characterized by two narrow valleys surrounded by mountains higher than 3000 m and Torino town just at the mountain feet, with complex interaction of the weather systems with the alpine chain. The behaviour of the meteorological models (even in the case of the high resolution limited-area models) in this area was not satisfying for the very precise forecasts required by the competition managers and the organisation, due to the bad description of the orography and to poor representation in the physical parametrization.

We faced this task organising a complex weather structure organisation and developing new methods in order to improve our forecasts. A very-dense weather station network, with standard ground stations, a dedicated radiosounding and two radar devices, was installed; a distributed weather office network, with long-trained skilled forecasters, was established; new techniques were studied and tested in the years before the event, like the Multimodel SuperEnsemble post-processing method applied on limited-area models(1).

In this work we present a rigorous evaluation of the weather forecast service (in the detailed short range and in the long range), with an outlook over the model results, the post-processing improvement and the human contribution to the forecasts.

The last Winter Olympics were characterized by quite interesting weather conditions, thus providing a very remarkable opportunity to look at the behaviour of a complex weather service "on the field" in the alpine area and to evaluate the contributions of its components. The procedures and new techniques developed for the Olympics are a significant inheritance of knowledge for the alpine weather forecast and for the post-olympic weather service.

(1)Cane D.,Milelli M.,Met. Zeit., 2006, 15/2, 207-214