Bora is a cold and gusty wind from northeasterly directions, common along the northern and central adriatic coasts. It’s a Wind which descents in the lee side of the Dinaric Alps and which has the same characteristics of the alpine Foehn. Bora differentiates from Foehn in the origin of it’s air mass, which is mostly much colder. The strongest windspeeds occur along the eastside of the northern Adriatic Sea, primarily during the cold seasons, and is particularly strong in the Gulf of Trieste, in the Vipava Valley in Slovenia and in the Kvarner Gulf in Croatia. Bora blows weaker also in other parts of Friuli, as well as along the adriatic coast.
The strength of Bora wind can be determined by the analysis of the air pressure difference (in hectopascal [hPa]) between Maribor (Slovenia) and Trieste. Bora arises when the air pressure in Maribor is about 4 hPa higher than in Trieste. Even though other parameters are also important, it’s possible to say that the greater this air pressure difference is, the stronger the Bora blows through the Gulf of Trieste. If the air pressure difference is higher than 8 hPa Bora can become tempestuous.
The Bora chart shows the forecast of the previously explained air pressure difference (Maribor – Trieste) for the following five days. The forecast is based on the statistic method MOS of MeteoGroup and is updated hourly.