PATERSON, Wash. — It will be a harvest to remember for an East Coast winemaker after an unbelievable misfortune, and the Washington grape grower who came to the rescue. It all started last week, when winemaker David Dunkenberger went out to his Virginia vineyard to pick his grapes. As he peered across the rows of grapes, there were fewer than he had remembered. And when he found clusters of grapes on the ground, he put two and two together.