Location: southwestern France, Languedoc
The marin is a mild and very humid southeasterly wind blowing onshore from the Mediterranean towards the mountain slopes of the Cevennes and the Montagnes Noire. Most frequent between early autumn and spring the marin is associated to low pressure across the Iberian Peninsula tracking eastward and frequently reaching gale-force during the passage of the warm front.
Together with its counterpart the dry northerly tramontane wind, the marin is the meteorologiocal heartbeat of the Languedoc and Lauragais regions. Close, humid, cloudy and misty along the coasts and often associated with thunder, the marin frequently has the potential to trigger heavy rains and violent flooding across the Cevennes and adjacent mountain regions. The mild, unstable and extremely wet Mediterranean air blows against the already relative cool uplands and slopes of the Cevennes, causing strong convection and intense orographic rainfall, eventually leading to the formation of one or more thunderstorm supercells.
As a result intensifying local low pressure starts to suck in more and more humid and mild air from the Mediterranean in order to fuel itself and the marin might eventually reach strong gale force, blowing at 9 to 10 bft. While rainfall rarely exceeds 10 or 20 mm along the coasts, official readings from mountain rain gauges are frequently recording several hundreds (!!) of litres of rainfall within 24 hours during such events. This phenomenon is locally known as the 'cevenol'. The devastating flash floods of fall 1999 and late summer 2002 are good examples for this.
When the marin wind blows through the Lauragais gap it becomes the Autun (Antane noir) of Aquitaine. The name marin points to its marine origin. However, in fact 'marin' is simply the local word for 'autan', which derives from the Latin altanus = from off shore. In addition l'autan is an old french word meaning 'the East'.