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Sailing
Cyclones and anti-cyclones
The weather changes in the Adriatic are determined by the positioning of cyclones and anti-cyclones above Central and South Europe. The usual movement direction of cyclones above the Adriatic is from the west and then eastwards. On their front sides they bring south direction winds (with mostly Jugo wind blowing at the time), and warm and humid air with them, so that the weather is cloudy and rainy. Following the cyclone, with the anti-cyclone raising in its strength and its spreading over European mainland eastwards, the wind turns north-eastwards and brings cold and dry air, Bura wind chases away the clouds, and after it and temporary low temperatures the weather gets stabilized. Until a new cyclone, nice and calm weather will be prevailing, with moderate Maestral wind in summer.
This rhythm of weather changes is common for the Adriatic. It differs only according to how often and on which routes the cyclones arrive. They are rare in summer and travel mostly north from the Adriatic.
The weather differences in summer and winter
The weather differences between north and south are significantly milder in summer - two halves of the Adriatic are then joined in one climate area with a lot of warm and sunny days, high temperatures during day moderated by pleasant Maestral wind, low humidity percentage and moderate nights. The sea temperature at its surface is mostly between 24 and 26 C along the whole coast.
Towards the end of the summer, the differences between North and South Adriatic become more significant, first at night while during day they are still more or less equal. Chilly nights soon cause the differences in the sea temperatures. The sea starts cooling more rapidly in the North at the beginning of September. A month later the sea will already have the temperature of 18C and less in front of Istria while in the South it can still keep the temperature of 22C.
The sea changes, currents and waves
The high and low tides are of quite small amplitudes in the Adriatic and they do not significantly affect the safety of sailing. The atmosphere pressure has a significant influence on them.
The sea changes are slightly indicated and in principal do not present problems at navigation. But nevertheless, they must be taken into account because in some strait canals and dug passages they can reach the speed of 4 knots.
Waves in the Adriatic are not so high as those in the oceans. Jugo creates higher waves than Bura but it would be completely wrong to draw a conclusion that they are more dangerous. On the contrary, Bura waves are shorter by half and their amplitudes are significantly less regular, meaning that the hull will have to endure much bigger strain under Bura waves.
Winds of the Adriatic
The whole easter side of the Adriatc is rich with completely particular local manifestations of weather changes. Reading of small signs have been the basis of fishing and naval life from long time ago. Therefore, you will not make a mistake if you ask a fisherman to tell you what the weather will be like until the evening or tommorow, and what is the best place mooring site.
Bura
As a cold wind, Bura blows horizontally from the nearby peaks towards the sea. It raises sea dust decreasing visibility. Bura is announced by "cap" of clouds seemingly attached to the peaks of the nearby high mountains - Velebit in the North Adriatic and Mosor and Biokovo in the South Adriatic.
Bura rarely blows for more than three days. When it is of local origin it can blow itself out for for as soon as less than 24 hours. Since it brings cold and heavy air, it finds its way to the sea through mountain faults and between higher ranges.
Jugo
Jugo is a south-east wind. It blows along the Adriatic while a cyclone is coming above the Adriatic area. It brings clouds and rain. The air pressure drops. It develops slowly and can usually be noticed two to three days in advance. It usually lasts much longer than Bura, five to seven days, and even longer in winter.
So called dry Jugo is also possible, when it keeps blowing without bringing rain.
Maestral
Maestral is a "good" wind, a friend to sailors and all those who enjoy the sea in summer. It is because it moderates the summer heat. It is a thermal north-west wind created by the differences in rates of mainland and sea warming. It is common from spring to autumn and strongest in July and August.
It usually raises about 9 or 10 in the morning, reaches its highest strength in the afternoon and suddenly fades at sunset. Maestral is generally weaker in the North Adriatic than in its South.
Nevera
Apart from Bura, nevera is certainly the most unpleasent experience in the Adriatic. It comes at high speed from the West from the open sea and lasts very shortly. It emerges almost exclusively in spring, much more frequently with autumn approaching. At the first sight of Nevera, necessary steps should be taken without delays. If there is possibility of moving aside from its route, that is the best thing to do
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