The Canadian Maritimes, specifically Nova Scotia and Prince Edward Island, are often affected by such snow squalls when an Arctic winter airmass moves over unfrozen waters. In PEI, sea-effect snow is often generated when a cold north wind blows over the unfrozen Gulf of St. Lawrence, dumping heavy snow on the north shore. In Nova Scotia, a cold north-west wind can produce sea-effect snow over the Cape Breton Highlands from the Gulf of St. Lawrence, and the Annapolis Valley from the Bay of Fundy; in the latter case, the sea-effect snow season can continue all winter as the Bay of Fundy remains open owing to its extreme tidal currents.