Tropical Storm Isaac was near hurricane force as it bore down on the U.S. Gulf Coast on Tuesday and was expected to make landfall in the New Orleans area seven years after it was devastated by Hurricane Katrina. Isaac’s swirling winds, rain and storm surge could pose a major test of New Orleans’ new flood control systems and reinforced levees. Forecasts from the U.S. National Hurricane Center showed the storm barreling ashore late on Tuesday or early Wednesday near southeastern Louisiana. Energy companies evacuated offshore oil rigs and shut down U.S. Gulf Coast refineries as the storm threatened to batter the oil refining belt.