The Northport Farmers' Market -- which went off as planned on the two past Saturdays but ran into bad weather each time -- has been extended for two more weekends. The market will open tomorrow and next Saturday from 9 a.m. until noon in the Cow Harbor parking lot, between Main Street and Woodbine Avenue. It has been offering produce from farms on the East End and a baymen's booth featuring lobster and clam chowder.