|
|
Miscellaneous Winds There are many stories on the origin of wind names, one of these refers to times when the island of Krf/Corfu' was an important commercial centre and some winds took the names from the lands they were blowing to that island. Thus we have inherited the alternative term grecale for the bora, that in Krf was called so because it was blowing from the direction of Greece, and libeccio from Lybia, and scirocco from Syria.
The bura (bora) and the jugo-siroco (scirocco) are the main winds on the Adriatic. They prevail in the winter period from September to May. The prevailing wind in the summer is the maestral. The atmospheric conditions in the region of Istria and the Kvarver demand of the nautical tourists a quick adaptation to the impetuous changes of the conditions of navigation. The main cause of such changes is the proximity of the mountain massif of Gosrski Kotar, and of the high mountain Učka/Monte Maggiore, whose sides plunge into the sea. Opposite Učka, looking from its 1500 metre high summit, at the end of the Kvarner Gulf one can see the long massive range of the Velebit. These geographical features are the main cause of the famous north easterly wind, the bora (bura). Genoa lows are low-pressure systems which develop to the south of the Alps in the region incorporating the Gulf of Genoa, Ligurian Sea, Po Valley, Gulf of Venice and northern Adriatic Sea. Although several factors are important in cyclogenesis, the development of the cyclone near the Gulf of Venice--as opposed to the west near the Gulf of Genoa--depends on the amount of cold air penetrating the Po Valley from the northeast. If there is little or no cold air entering the Po Valley, the low will probably form in the Gulf of Venice; otherwise, cyclogenesis will occur to the west. Genoa cyclones usually remain stationary (or at least leave a residual trough) south of the Alps throughout their life history. If the lows do move, they generally follow one of two tracks.
Secondary Winds The tramontana is a north/north-westerly wind and a type of bora. Differing from the maestral, it blows at the end of the Gulf of Kvarver (near Preluka). The tramontana is sometimes violent and can raise sea height at the entrance to Luka Zadar. One strong November thunderstorm caused northerly tramontana winds of 108 kt (200 kph) at Koper. Tramontana squalls are usually associated with cold frontal passage, preceded by a rise in relative humidity, and drop in pressure. The duration of such events is quite brief, but care should be exercised in dispensing small boats to the harbor when frontal passage is anticipated. This is the preferred wind for surfers, hardly a day passing without this strong and cold wind, the bearer of freshness from the mountains, reaching to the northern shores of the islands of Krk and Cres. Lebić is a southwesterly wind which blows mainly in spring, can cause troubles at sea, but luckily it is not frequent. Summer days are often refreshing thanks to "maestral" - a northwesterly wind. The lebić often follows the jugo in springtime as a violent southwesterly wind in most regions along the Croatian coast. Wave action is somewhat heightened in Luka Gazenica near Zadar when such winds occur along the north pier of the port, where U. S. vessels tie up. Luka Zadar is completely protected from lebić wind and sea state effects. The lebić occurs as a low pressure center moves on a track across the northern Adriatic, north of Zadar. The changing wind direction from SE to S to SW does produce choppy seas at the anchorage locations in Zadarski Kanal, which can pose problems for small boats arriving or departing the anchorage area. The lebić also occurs during October, usually following a jugo. The rapidly changing wind direction in a lebić, from SE to S to SW, frequently causes confused, choppy, sea state that can be dangerous for small boats attempting to load or offload personnel at either of the anchorages in Zadarski Kanal. Zmorac is a day wind coming from the sea is not particularly important for the area, but it's frequent and strong enough (between 3.00 and 4.00 p.m.) to help endure the unpleasant summer heat. It also has some other favourable physiological effects. At night there is sometimes a refreshing wind coming from the nearby terraces. Bibliography:
|
