Identification of extreme weather phenomena in near real-time

This paper describes an operational system for defining weather phenomena and indices, as well as, identifying and documenting extreme weather conditions based on the hydrometeorological observations from meteorological stations. The results are published directly on the website of the Hydrological Observatory of Athens. Different techniques are implied in real time in order to identify and exclude data errors from further processing. Extreme weather phenomena, such as extreme heat, frost, intense and heavy rainfall and extreme windy conditions, are currently monitored. Moreover, bioclimatic indicators measuring the felt air temperature (heat index and wind chill) by combining more than one meteorological variable are calculated. The system provides the flexibility to define weather phenomena and indices and to apply the identification algorithm to time series stored in the hydrometeorological database.