In addition to synoptic scale situation modified by mesoscale contributions, sailors in the Adriatic should consider the micro-scale drivers that may affect their exposure to local weather conditions while in anchorage.
These factors may result from the local geography resulting in very local anabatic and katabatic winds as already mentioned in mesoscale drivers. However, these mesoscale drivers may be expressed at very different scales at the local level, not always captured on the local weather forecast.
Several effect are influencing these factors:
All of the above can be affected by the local geography. Katabatic winds falling down the slopes may not have enough energy to go over islands elevation they encounter on their way and therefore tend to go around obstacles, funnelling through islands on their way.
This may result in an island looking like offering protection from Bora on a map, but not actually offering it because of a low altitude pathway allowing wind gust to get over the so-called “protected area”.
This is exactly what we encountered in Borovinje cove, as Bora was forecasted and Navily was indicating potential good protection. To be honest, some other posts were mentioning a funnelling effect. We did not sleep the whole night and left fin the following morning. See picture below.
In the lee side of an island:
- the air may tumble and swirl,
- with rapid changes in direction and speed over short distances.
