A fall wind is a type of downslope wind. Like katabatic winds, it is driven by the flow of an elevated, high-density (usually cold) air mass into a lower-density (warmer) air mass, but the term fall wind is restricted to the cases where the cold air mass is not due to radiative cooling of a slope, but to the presence of a dense air mass at the top of a slope. A well-known example of a fall wind is the Bora in the

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

region, to the extent that the term ‘bora wind’ is sometimes used to designate a fall wind. The presence of the dense (cold) air mass at the top can be caused by various meteorological phenomena, such as the arrival of a cold front, or from the advection of cool marine air by a

sea breeze A sea breeze or onshore breeze is a wind that blows in the afternoon from a large body of water toward or onto a landmass. By contrast, a land breeze or offshore breeze is a wind that blows in the night from a landmass toward or onto a large ...

. The flow of the dense air mass during fall winds events is similar to the flow of water over a dam, with a

hydraulic jump A hydraulic jump is a phenomenon in the science of hydraulics which is frequently observed in open channel flow such as rivers and spillways. When liquid at high velocity discharges into a zone of lower velocity, a rather abrupt rise occurs in ...

found downstream. Examples of fall winds are the Bora in the

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

, the Athos fall wind in Greece, or the Marinada in

Catalonia Catalonia is an autonomous community of Spain, designated as a ''nationalities and regions of Spain, nationality'' by its Statute of Autonomy of Catalonia of 2006, Statute of Autonomy. Most of its territory (except the Val d'Aran) is situate ...

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Wind {{Improve categories, date=December 2024