Economists busy revising down their third quarter gross domestic product forecasts had to backpedal a bit on Thursday after Commerce Department data showed a steep shrinking of the U.S. trade deficit — despite an unexpected rise in weekly jobless claims. The trade gap shrank to $44.8 billion in July, Commerce Department data showed, down sharply from June’s $53.1 billion deficit and much lower than forecasts around $51 billion. The 13.1 percent decline was the biggest month-to-month percentage drop in the deficit since February 2009.