(CNN) Even as power was fully restored late Saturday morning at New Orleans' main airport, nearly 84,000 customers in the region were still without electricity as the remnants of Tropical Storm Olga moved across the Gulf Coast.

Olga is expected to bring heavy rain Saturday to parts of Louisiana and Mississippi, according to the National Weather Service. The central Gulf Coast into the Lower Mississippi Valley and western Tennessee Valley could receive 3 to 6 inches of rain, forecasters said.

Coastal flooding from above normal tides and isolated tornadoes are possible Saturday as the storm moves in, the weather service said.

The storm, which was downgraded Friday night to a post-tropical cyclone, began causing disruptions early Saturday. Entergy New Orleans reported around 6 a.m. ET that tens of thousands of customers were without power. The number ticked up as the morning went on.

Louis Armstrong New Orleans International Airport reported hours later that its power had been restored.

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