Galerna

thumb|260x260px|Sudden advance of a cold front, a similar situation to the one triggering a galerna. A galerna (Basque: enbata) is a sudden and violent storm with strong wind gusts from the west or northwest that affects coastal areas of the Cantabrian Sea and the Bay of Biscay, predominantly from spring to fall. It especially affects the central and eastern part of the Spanish north coast provinces (Asturias, Cantabria, Biscay and Gipuzkoa) and the southwestern region of France (French Basque Country, Quercy, Touraine, Berry, Deux-Sèvres, Vendée, and Brittany). The name comes from French galerne and that originates from Breton (gwalarn), a wind from the northwest.

==Description== They usually occur during warm and calm days when a cold front causes a sudden change in wind direction and intensity that can exceed 100 km/h. The sky darkens and there is a sudden decrease in temperature of up to 12 °C in 20 minutes, rapid increase in atmospheric pressure, and a rise in relative humidity. The resulting wave heights in the coastal ocean range from rough to very high on the Douglas Sea scale. Precipitation is not usually associated with galernas, although it can occur occasionally.