The microburst hit Annisquam on a late afternoon last month. A surprise from a line of summer thunderstorms, its winds clocked over 100 miles per hour. Under driving rain, power lines fell, trees uprooted, windows blew in, shingles flew, fences came down. Across Lobster Cove, the village harbor off Cape Ann's Ipswich Bay, 25 sailboats flipped at their moorings. A tour boat from Gloucester taking shelter in the cove ran aground.