Development of the Bulgarian national weather early warning system

The National Institute of Meteorology and Hydrology is the national weather service of Bulgaria. It has been operating a national weather early warning system for more than 10 years. The national system has been developed in accordance with the principles of the European system METEOALARM built within the international cooperation facilitated by the EUMETNET – a network of European national hydro-meteorological services. The color warning scale of METEOALARM gained popularity in the country and is currently easily recognizable by the wider public. Originally the national weather early warning system was develop to provide warnings with coarser resolution at the level of administrative region – 28. The advantage is that such warnings can be directly used for decision making by the civil protection authorities that often have territorial branches with zones of responsibility matching the bigger administrative regions. The disadvantage is that the natural extreme weather events are of scale smaller than that of an administrative region or occur in a part of it. This is a source of potential misunderstanding that requires detailing by text or specific consultation with a forecaster if useful decision is to be made upon. The national weather early warning system consists of three steps: 1. Automatic extraction of weather warnings by administrative regions from the regional numerical weather prediction model of NIMH - the result is offered to the weather forecaster in duty as first guess; 2. Evaluation of the first guess and and weather warning issuance by the forecaster in duty; 3. Dissemination to authorities and the general public by website, email, radio. The most recent development of the system was to go to finer resolution and provide weather warning for municipalities – 265. The advantage is that it allows for better match in scale between natural phenomena and the area of the municipality. The disadvantage is that it is much harder to produce by the forecaster. This is where the automatic first guess from model becomes essential. Sea storm early warnings for the Black sea coast for dangerous wave height has also been added during the last years.