analyzing the behaviour of selected risk indexes during the 2007 greek forest fires

greece has experienced particularly severe and frequent forest fires during summer 2007 together with exceptionally dry meteorological conditions culminated in distinct heat waves. the present study analyzes the time pattern of daily values of two fire risk indices (nesterov and angstrom) based on meteorological data made available for a number of gauging stations between 1 june and 31 august over the 1998-2013 time interval. weather data were supplemented with meteorological re-analysis profiles with the aim to validate the daily outputs of the two fire risk indices in extreme climatic conditions. nesterov and angstrom indices classified summer 2007 meteorological conditions as exceptional with high probability of fire occurrence during the whole dry season in the majority of greek regions. meteorological re-analysis indicates a high deviation of selected upper atmospheric variables from the climatic average since early july 2007 representing persistent and widespread meteorological conditions favourable to fire occurrence in greece. the crucial role of indicator-based monitoring of heat waves and exceptionally-dry meteorological conditions for mega-fire surveillance in the mediterranean basin was finally discussed.