Meltemi is the Greek and Turkish name for the well known Etesian wind blowing from north to northwest across the Aegean Sea. The Meltemi flows from a high pressure ridge over the Balkans towards a heat trough over the Anatolian Plateau. During a strong meltemi event, the trough may extend relatively far to the west and beyond Rhodes and even Crete, forming calm wind pockets leeward of the Aegean islands.
However, the numerous Aegean Islands and mountain gaps are channeling the wind causing gusty, vigorous jet-effects and lee eddies as well as local Katabatic winds. Although the Etesian winds are part of the large scale Asian monsoon system, the Meltemi might also be caused or enhanced by regional-scale weather patterns, i.e. a local heat trough over Turkey and relatively cold Aegean waters and resulting high pressure. This is especially true at the beginning and end of the Meltemi season (May to October).
Typical weather associated with a Meltemi event is dry with clear skies. Especially during the high season (July to August) a Meltemi is heralded by scattered altocumulus and sometimes orographic clouds on the lee side of islands during the previous day. Typically a Meltemi is accompanied by a sudden drop in humidity, improved visibility and a raise in atmospheric pressure.