Bora

A strong, cold, and dry northeasterly katabatic wind that blows from the land to the sea, particularly along the eastern Adriatic coast.

The bora is a regional wind phenomenon most commonly associated with the Adriatic Sea, particularly affecting areas such as the Croatian and Montenegrin coastlines, as well as parts of Italy and Slovenia. It originates from the interior highlands and descends rapidly towards the coast, gaining speed as it funnels through mountain passes and valleys. The bora is typically cold and dry, often occurring in winter but possible at other times of the year. It can be sudden and violent, with gusts sometimes exceeding 100 knots, creating hazardous conditions for navigation and mooring.

There are two main types of bora: the clear bora, which occurs under high-pressure conditions and brings clear skies, and the dark bora, which is associated with low-pressure systems and often brings clouds and precipitation. The bora’s strength and unpredictability can cause significant sea disturbances, including steep waves and dangerous cross-seas, making it a critical factor in voyage planning and safety for vessels operating in affected regions. Mariners in the Adriatic are particularly vigilant for bora warnings, as its onset can be rapid and its effects severe, especially in narrow channels and near exposed coastlines.