MIAMI (AFP) - A strengthening Tropical Storm Lee lurched toward the US Gulf Coast on Saturday, dumping heavy rain on Louisiana and threatening extensive flooding that will put the New Orleans levee system to the test. Oil companies evacuated workers from offshore rigs ahead of the arrival of Lee, a disorganized but major rainmaker, while Louisiana Governor Bobby Jindal declared a state of emergency. "Flooding is our primary concern," Jindal said on Friday, urging residents to "prepare for the worst and hope for the best." Officials warned that the slow-moving storm could bring the same kind of flooding that residents in the northeast are still grappling with after Hurricane Irene tore up the US East Coast last weekend, leaving nearly 50 people dead and millions of households without power. With experts forecasting the storm will turn to the northeast and push inland, one of the biggest dangers from Lee could be in the Appalachians.