The public warning alerts in Croatia using the CB/SMS communication channel – special focus on severe thunderstorm warning

Croatian Meteorological and Hydrological Service (DHMZ) is responsible for weather warnings in Croatia and issued it on official webpage meteo.hr, as well as on meteoalarm.org. Information about weather warnings are communicated with Civil Protection Directorate (CPD) using standard operation procedure on everyday basis. Additionally, DHMZ uses social networks and media for distribution of the weather warnings to the public. But, in 2023 a huge step was done in alerting the public. Ministry of Internal Affairs of the Republic of Croatia formed the procedure for CB/SMS warning system – Early Warning and Crises Management System (SRUUK). Although system was in the final phase in 2023, severe derecho storm in July that hit continental part of Croatia and cause huge damage, unfortunately, also four fatalities, was the big additional motivation for the earliest possible operational application, and it started in August 2023.

DHMZ has a crucial role in decision to alert the public via CB/SMS message when the severe weather phenomena tend to develop into a major accident or disaster, while CPD coordinates the actions of all collaborators included in SRUUK. Since 2023 for few possible severe thunderstorm episodes the SRUUK was activated. In two cases forecasted extremely severe weather phenomena did not occur, although the environment was very conductive for severe organized convective thunderstorm. This reflects key issues in alerting the public via CB/SMS messages for severe thunderstorm. These are: definition of criteria in what kind of convective favorable environment the message should be sent, what information the message contain, when the message will be sent – for very likely forecast event (even more than 12 hours in advance) or for the severe thunderstorm that is already developed. It is necessary to have in mind that under certain conditions, such a warning can cause additional panic, further endangering human lives. Because of all of the above, extensive preparation is necessary, especially in cases of thunderstorms which are one of the most challenging to forecast, in order to maintain or build a high level of trust within the public.