Bora is a northern to north-eastern
katabatic windA katabatic wind, from the Greek word katabatikos meaning "going downhill", is the technical name for a drainage wind, a wind that carries high density air from a higher elevation down a slope under the force of gravity. Such winds are sometimes also called fall winds.Not all downslope winds are...
in the
AdriaticThe Adriatic Sea is a body of water separating the Italian Peninsula from the Balkan peninsula, and the system of the Apennine Mountains from that of the Dinaric Alps and adjacent ranges. The Adriatic Sea is a part of the Mediterranean Sea...
,
CroatiaCroatia , officially the Republic of Croatia , is a country in southeast Europe, at the crossroads of the Pannonian Plain, the Balkans, and the Mediterranean Sea. Its capital is Zagreb...
,
ItalyItaly , officially the Italian Republic , is a country located on the Italian Peninsula in Southern Europe and on the two largest islands in the Mediterranean Sea, Sicily and Sardinia. Italy shares its northern, Alpine boundary with France, Switzerland, Austria and Slovenia...
,
GreeceGreece , officially the Hellenic Republic , is a country in southeastern Europe, situated on the southern end of the Balkan Peninsula....
, and
TurkeyTurkey , known officially as the Republic of Turkey
, is a Eurasian country that stretches across the Anatolian peninsula in Western Asia and Thrace in the Balkan region of southeastern Europe...
. Its name derives from the
Greek mythologicalGreek mythology is the body of myths and legends belonging to the ancient Greeks concerning their gods and heroes, the nature of the world, and the origins and significance of their own cult and ritual practices. They were a part of religion in ancient Greece...
figure of Boreas/Βορέας, the North Wind.
Features
The changeable Bora can often be felt all over
DalmatiaDalmatia , is a region on the eastern coast of the Adriatic Sea and is situated in modern Croatia. It spreads between the island of Rab in the northwest and the Bay of Kotor, in Montenegro, in the southeast...
and the rest of the Adriatic east coast. It blows in gusts. The Bora is most common during the winter. It blows hardest, as the meteorologist Baron
Ferdinand von WrangelBaron Ferdinand von Wrangel was a Baltic German, explorer, Honorable Member of the Russian Academy of Sciences in St. Petersburg , one of the founders of the Russian Geographic Society...
explained it by extending Julius Hann's explanation of Alpine katabatic winds to the north Adriatic, when a polar high-pressure area sits over the snow-covered mountains of the interior plateau behind the Dinaric coastal mountain range and a calm low-pressure area lies further south over the warmer Adriatic. As the air grows even colder and thus denser at night, the Bora increases. Its initial temperature is so low that even with the warming occasioned by its descent it reaches the lowlands as a cold wind. The wind takes two different traditional names depending on associated meteorological conditions: the "light bora" (Italian:
Bora chiara) is Bora in the presence of clear skies, whereas clouds gathering on the hilltops and moving towards the seaside with rain characterize the "dark bora" (
Bora scura).
Areas hit
The area where some of the strongest bora winds occur is the
VelebitVelebit is the largest though not the highest mountain range in Croatia. Its highest peak is the Vaganski Vrh at 1757 m.The range forms a part of the Dinaric Alps and is located along the Adriatic coast, separating it from Lika in the interior...
mountain range in
CroatiaCroatia , officially the Republic of Croatia , is a country in southeast Europe, at the crossroads of the Pannonian Plain, the Balkans, and the Mediterranean Sea. Its capital is Zagreb...
. This seaside mountain chain, spanning 145 kilometers, represents a huge weather and climatic divide between the sharp
continental climateContinental climate is a climate that is characterized by winter temperatures cold enough to support a fixed period of snow cover each year, and relatively moderate precipitation occurring mostly in summer, although east coast areas may show an even distribution of precipitation.Regions containing...
of the interior, characterized by significant day/night temperature differences throughout the year, and the Adriatic coast, with a
Mediterranean climateA hi Mediterranean climate resembles the climate of the lands in the Mediterranean Basin, which includes most of the area with this climate type worldwide...
. Bora occurs because these two divided masses tend to equalize. Sailing can be extremely dangerous for an unexperienced navigator in the Velebit channel because the wind can start suddenly on a clear and calm day and result in major problems, frequently also affecting road traffic. Near the towns of
SenjSenj is a town in the Lika-Senj county of Croatia, population 8,132 . It is located on the Adriatic coast below the Vratnik mountain pass which separates the Velebit mountain from the mountains of Gorski kotar...
,
Stara Novalja
Stara Novalja is a village in the cove of the same name in the north-eastern part of the island of Pag, 5 kilometers north of Novalja in Croatia. The Economy is based on farming, wine culture, fishing and tourism....
,
KarlobagKarlobag is a municipality on the Adriatic coast in Croatia, located underneath Velebit overlooking the island of Pag, west of Gospić and south of Senj. The Gacka river also runs through the area...
and the southern portal of the Sv. Rok Tunnel in Croatia, it can reach speeds of up to 220 kilometers per hour. On 15 March 2006 the speed of a gust on the
PagPag may refer to:* Periaqueductal gray* Pag * Pag * ISO 639-2 and ISO 639-3 code for the Pangasinan languageSee also* PAG...
Bridge was measured at 235 kilometres per hour.
The wind is also an integral feature of Slovenia's
Vipava ValleyVipava Valley is a valley located in the Slovenian Littoral, between the towns of Nova Gorica and Vipava. It is a narrow valley, serving as the main passage between Friulian lowland and central Slovenia, and thus also an important corridor connecting Northern Italy to Central Europe...
and
KrasKras , also known as the or the Kras Plateau, is a limestone borderline plateau region in southwestern Slovenia extending into northeastern Italy. It lies between the Vipava Valley, the low hills surrounding the valley, the westernmost part of the Brkini Hills, northern Istria, and the Gulf of...
region (known as Carso in Italy), an area of limestone heights over the
Gulf of TriesteThe Gulf of Trieste is a shallow bay of the Adriatic Sea, in the extreme northern part of the Mediterranean Sea. It is part of the Gulf of Venice and is shared by Italy, Slovenia and Croatia...
stretching towards the
IstriaCroatian Istria , formerly Histria , is the largest peninsula in the Adriatic Sea. The peninsula is located at the head of the Adriatic between the Gulf of Trieste and the Bay of Kvarner...
n peninsula. Because the region separates the lower Adriatic coast from the
Julian AlpsThe Julian Alps are a mountain range of the Southern Limestone Alps that stretches from north-eastern Italy to Slovenia, where they rise to 2,864 metres at the Triglav mountain. They are named after Julius Caesar, who founded the municipium of Cividale del Friuli at the foot of the mountains...
range, extreme bora winds often occur there. They have influenced the region's traditional lifestyle and architecture. Towns on the coast, where the Bora also frequently occurs, are built densely with narrow streets in part because of the wind. Buildings in several towns and villages in
SloveniaSlovenia , officially the Republic of Slovenia , is a country in Central Europe bordering Italy to the west, the Adriatic Sea to the southwest, Croatia to the south and east, Hungary to the northeast, and Austria to the north...
and the
Province of TriesteThe Province of Trieste is a province in the autonomous Friuli-Venezia Giulia region of Italy. Its capital is the city of Trieste.It has an area of 212 km², and a total population of 236,520...
(
ItalyItaly , officially the Italian Republic , is a country located on the Italian Peninsula in Southern Europe and on the two largest islands in the Mediterranean Sea, Sicily and Sardinia. Italy shares its northern, Alpine boundary with France, Switzerland, Austria and Slovenia...
) have stones on their roofs to prevent the roof tiles from being blown off. Chains and ropes are occasionally stretched along the sidewalks in downtown
TriesteTrieste is a city and seaport in north eastern Italy. It is situated towards the end of a narrow strip of land lying between the Adriatic Sea and Italy's border with Slovenia, which lies almost immediately south, east and north of the city...
, Italy, to facilitate pedestrian traffic. A strong bora will often be reported on Italian television news.
Strong bora winds also occur in the
Tsemes BayThe Tsemes Bay is an ice-free bay located on the northern coast of the Black Sea, in Krasnodar Krai of Russia. It takes its name from the Tsemes River which flows into the bay. The depth of the sea varies from 21 to 27 meters...
of the
Black Seaur a loser!The Black Sea is an inland sea bounded by Europe, Anatolia and the Caucasus and is ultimately connected to the Atlantic Ocean via the Mediterranean and Aegean Seas and various straits. The Bosporus strait connects it to the Sea of Marmara, and the strait of the Dardanelles connects it to...
near the Russian port of
NovorossiyskNovorossiysk is a city in southern Russia, the main Russian port on the Black Sea, in Krasnodar Krai. It is one of the few cities honoured with the Soviet title of the Hero City. Population: 281,400 ; -History:...
, where they are known as nordost. They can reach speeds of up to 220 kilometres per hour.