The search for clues to whether the Federal Reserve will raise U.S. interest rates in September for the first time in nearly a decade is set to intensify next week. “Because this report was not extraordinarily strong, it was simply in line with expectations, that leaves the markets having to look toward other data,” said Paul Christopher, head global market strategist at Wells Fargo Investment Institute in St. Louis. July retail sales, expected on Thursday, will be the key number to look for, while comments by policymakers Dennis Lockhart and William Dudley will also be carefully scrutinized.