Gregal (from Catalan/Italian, referring to Greece) is the north-easterly wind in the Mediterranean wind rose. In the Balearic Islands and along the Catalan coast, it can blow with considerable force, bringing cold, moist air that produces rainfall, especially on east-facing slopes.
Effects on navigation
It is feared by western Mediterranean sailors because it generates cross seas on northeast-facing coasts. It can persist for several days when an anticyclone sits over central Europe and a low develops in the western Mediterranean, channelling cold air between the two systems.