The whole eastern part of the Adriatic abounds with local weather variations, where winds take the top position with regard to sailing. Since ancient times, reading the signs of nature has been at the core of the life at sea. Therefore, you won’t go wrong, if you ask a local fisherman, what will be the weather condition today in the evening or tomorrow, what is the best mooring or anchor sites? The wind rose of the Adriatic is made by Jugo (south-easterly wind), Bura/Bora (north-easterly wind), Maestral / Mistral (north-easterly wind), Sirocco (southerly wind), Tramuntana (northerly wind), Levanter and easterly wind. Regardless of all these Adriatic winds, special attention shall be given to Bura and Jugo, and there are good reasons why. First of all, our goal is to present the Adriatic winds and make them easy for you to recognize, to take advantage of their energy, as well as to timely react at their formation and reach swiftly a safe harbour.
Bura – a cold Adriatic wind
As a cold wind, Bura vertically descends the slopes of the coastal mountains and moving towards the sea. It thus creates dust clouds that reduce visibility. Bura is announced by a “cap” of clouds that seem as though they have grabbed the high mountain peaks – Velebit in the north Adriatic, Mosor and Biokovo in the south Adriatic. It rarely blows for more than three days. When Bura is of local origin, it will blow itself out in less than a day. Since it brings cold and heavy air, it finds its way towards the sea through mountain faults and between higher mountain ranges. Bura blows in gusts and therefore might be very severe and unexpected, so, if you have not encountered Bura so far, we advise you to reach the nearest harbour.
The areas where some of the strongest Bura winds occur are: Trieste Bay, Velebit channel famous for the Bura of Senj), Vinodolski channel, Bay of Novigrad, areas around Sibenik, Split (in particular Vrulja near Omis), Makarska – lowlands of Biokovo, Zuljan Bay on the Peljesac peninsula, River Neretva estuary, Risan Bay in Boka. On the contrary, areas where some of the mildest Bura winds occur are: western coast of Istria, southern area of Biokovo stretching towards Trogir, from the coast of Poljice to Dugi Rat, as well as the coast of Montenegro. In short, it might be said that where coastal hilltops are lower than 600 meters or more than 4 kilometres from the coast, the mildest Bura winds occur.
Jugo – warm Adriatic wind
Jugo is a south-easterly wind. It blows across the Adriatic when a cyclone develops over the Adriatic area. It brings clouds and rain. The air pressure drops. It develops slowly and it can usually be noticed two or three days in advance. It usually lasts longer than Bura, five to seven days, and even longer in winter.
There is a possibility of the so called dry Jugo, when it blows for a couple of days without bringing rain. Unlike Bura, Jugo is a constant wind that gradually gains strength.
Mistral is a “benevolent”, a friendly wind looked forward by especially sailors and all those who enjoy the summer season under its breeze. Mistral is a daily wind blowing from the northwest and created by the differences in temperature between the mainland and sea. It is fairly frequent from spring to autumn and strongest in July and August.
It usually starts blowing around 9 or 10 in the morning, reaches its highest strength in the afternoon and fades at sunset. Mistral is generally weaker in the north Adriatic than in its south.
Tramuntana is a classical name for a northern wind. The word derived from Latin vertus transmontanus – a wind that blows (comes) across the mountains. This name for a northern wind is widely used throughout the Mediterranean. It is a cold wind of moderate strength (sometimes strong gusts), that usually forms in clear weather. Its appearance announces nice weather.
The Levanter refers to an easterly wind. The name comes from Italian levante meaning east, whereas the word developed from Latin levare: uplift, elevate. It is often a moderate (rarely strong) wind, carrying clouds, moisture and precipitation. When it reaches high intensity, it is described as Levanter.
Ostro is a common name for a southerly wind. Its name is derived from Latin auster : south. It is described as a warm and humid wind that usually does not last long, but it might become reach considerable strength.
Libeccio is a south-westerly Adriatic wind described both as lebic and garbin. It is usually a dry and warm wind, which rises across the Adriatic after Jugo, when the Mediterranean cyclone arriving from the sea reaches the western and central coast of Croatia. It usually does not last long, but it might give violent squalls (lebicada). It is especially dangerous because of wave “crossing” and rising of the sea surface in shallow harbours that are open to the south-west. Garbin, grbin, garbinada (from Arab gharbi) is a very strong, sudden and short-lived south-westerly (or westerly south-westerly) wind. It can cause muddy waters, in case of sand or gravel beaches.
Cyclones and anticyclones
The formation of cyclones and anticyclones over central and southern Europe dictates changes in Adriatic weather conditions. The usual direction of cyclone movement over the Adriatic is from west to east. Their fronts bring southerly winds (when the jugo blows along the Adriatic), with a flow of warm, wet air to the Adriatic, making the weather cloudy and rainy. Behind the cyclone, as the anticyclone gains in strength and expands over the European mainland towards the east, the wind veers NE and brings with it cold, dry air; the bura clears away the clouds, and following it there is a temporary drop in temperature, but the weather stabilises. This stabilisation is characteristic of Adriatic weather, with clear, sunny skies, and a daily maestral during the summer, until the arrival of a new cyclone repeats the entire cycle.
This rhythm of changes is common in the Adriatic, and varies only according to the frequency and trajectories of cyclones. They are rare during the summer when they mostly move above the Northern Adriatic.
Summer and winter differences
Differences between the north and south Adriatic weather situations are significantly milder during the summer – this is when the two halves of the Adriatic merge into a single climate region, with many warm, sunny days, high daily temperatures soothed by the pleasant maestral, low humidity and nights which are not too hot. The surface temperature of the sea is mostly between 24° and 26°C throughout the Adriatic.
At the end of the summer, the differences between the northern and southern Adriatic become more marked at night, while daily temperatures remain more or less the same. Colder nights soon begin to contribute to the cooling of the sea, which quickly becomes colder around the beginning of September. A month later, the Istrian sea will have cooled to 18°C or less, while in the south it will still be around 22°C.
Tides, currents and waves
The amplitudes of the Adriatic tides are relatively small and do not affect safety at sea significantly. Atmospheric pressure has a significant effect on them.
Sea currents are weak and do not usually present navigational problems. But they should still be taken into consideration, especially in narrow channels and passages, where they can gain up to 4 knots in speed.
The waves of the Adriatic are not as high as ocean waves. The jugo creates more waves than the bura, but it would be foolish to conclude that jugo waves are less dangerous. On the contrary, bura waves are half the length, and irregular in amplitude, which means your hull will be under much greater stress than during the jugo.
In terms of weather conditions in the Adriatic, squalls are the most unsettling experiences, next to the bura. They arrive at great speed from the west, from the open sea, but are short-lived. They almost always occur during summer and lessen in frequency as autumn approaches. At the first sign of a squall, take precautions without delay. If you can shelter from its path, you would be well advised to do so.