Last-minute shopping in the days leading up to Christmas may make up for lost weekend sales on the U.S. East Coast after record snowfalls shut stores early and kept shoppers at home, the National Retail Federation said. The weather wasn't enough to prompt the trade group to revise its forecast for a 1 percent drop in holiday sales, said Ellen Davis, a spokeswoman for the NRF. Some retailers may extend promotions into Monday and Tuesday to attract shoppers they had hoped to get during the last weekend before Christmas, she said yesterday. "There are more than enough shopping days to make up any challenges due to weather in the east," Matt Rubel, chief executive officer of Collective Brands Inc., said in an e-mail yesterday. Collective Brands, based in Topeka, Kansas, is the owner of the Stride Rite and Payless ShoeSource chains. Retailers in the Washington area closed early on Dec. 19 and opened to fewer shoppers yesterday than is typical for the last weekend before Christmas. As much as 24 inches of snow fell on Bethesda, Maryland, while 16 inches were measured at the National Mall in Washington and 23.2 inches were recorded at Philadelphia International Airport, the National Weather Service said. Shopping during the past weekend probably trailed the one following Thanksgiving, said Aaron Martin, a spokesman for researcher ShopperTrak RCT Corp., in an e-mail yesterday. The firm had anticipated the weekend would be the best of the season and in October forecast a 1.6 percent increase in total holiday sales.