Košava ( sr-cyr, Кошава, ) is a cold, very

squall A squall is a sudden, sharp increase in wind speed lasting minutes, as opposed to a wind gust, which lasts for only seconds. They are usually associated with active weather, such as rain showers, thunderstorms, or heavy snow. Squalls refer to the ...

y southeastern

wind Wind is the natural movement of air or other gases relative to a planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heating of land surfaces and lasting a few hou ...

found in parts of Eastern Europe and the Balkans. It starts in the

Carpathian Mountains The Carpathian Mountains or Carpathians () are a range of mountains forming an arc across Central Europe. Roughly long, it is the third-longest European mountain range after the Urals at and the Scandinavian Mountains at . The range stretches ...

and follows the

Danube The Danube ( ; ) is a river that was once a long-standing frontier of the Roman Empire and today connects 10 European countries, running through their territories or being a border. Originating in Germany, the Danube flows southeast for , pa ...

northwest through the Iron Gate region where it gains a jet effect, then continues to

Belgrade Belgrade ( , ;, ; Names of European cities in different languages: B, names in other languages) is the Capital city, capital and List of cities in Serbia, largest city in Serbia. It is located at the confluence of the Sava and Danube rivers a ...

. It can spread as far north as

Hungary Hungary ( hu, Magyarország ) is a landlocked country in Central Europe. Spanning of the Carpathian Basin, it is bordered by Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the south, Croatia a ...

and as far south as

Niš Niš (; sr-Cyrl, Ниш, ; names in other languages) is the third largest city in Serbia and the administrative center of the Nišava District. It is located in southern part of Serbia. , the city proper has a population of 183,164, while ...

and Sofia. In the winter, it can cause temperatures to drop to around . In the summer, it is cool and dusty. It varies diurnally, and is strongest between 5:00 and 10:00 in the morning. Košava is usually caused by a low

pressure Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and e ...

zone over the

Adriatic Sea The Adriatic Sea () is a body of water separating the Italian Peninsula from the Balkan Peninsula. The Adriatic is the northernmost arm of the Mediterranean Sea, extending from the Strait of Otranto (where it connects to the Ionian Sea) to t ...

and a corresponding high pressure zone in southern

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

. The name is also used traditionally in northwestern

Bulgaria Bulgaria (; bg, България, Bǎlgariya), officially the Republic of Bulgaria,, ) is a country in Southeast Europe. It is situated on the eastern flank of the Balkans, and is bordered by Romania to the north, Serbia and North Macedon ...

to mean a northeastern or eastern wind. There is a saying that goes: "When košava blows, the

Nišava The Nišava or Nishava (Bulgarian and sr-Cyrl, Нишава, ) is a river in Bulgaria and Serbia, a right tributary, and with a length of also the longest one, of the South Morava. Course Bulgaria The Nišava originates in western Bulgar ...

freezes". The speed and occurrence of the Košava wind declined from 1949 to 2010. The same study showed that Košava usually lasts for two or three days, one-day events being very rare. Košava wind blows when there is a high air pressure (an anticyclone) over eastern Europe and/or west Asia and a low pressure (a cyclone) over the middle and/or western Mediterranean region. The strong anticyclone, however, is the main trigger for the Košava wind. Košava is also a gap flow windstorm. Košava's occurrence can be successfully forecast using the across-mountain

mean sea level pressure Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1013.25 millibars, 7 ...

and

potential temperature The potential temperature of a parcel of fluid at pressure P is the temperature that the parcel would attain if adiabatically brought to a standard reference pressure P_, usually . The potential temperature is denoted \theta and, for a gas well-a ...

differences.

References

Winds Climate of Serbia Climate of Bulgaria {{Serbia-stub

See also

References