NEW ORLEANS — With its massive size and ponderous movement, a strengthening Isaac could become a punishing rain machine depending on its power, speed and where it comes ashore along the Gulf Coast.

The focus has been on New Orleans as Isaac takes dead aim at the city seven years after Hurricane Katrina, but the impact will be felt well beyond the city limits. The storm’s winds could be felt more than 200 miles from its center.

The Gulf Coast has been saturated because of a wet summer, and some officials worry that more rain could make it easy for trees and power lines to fall over in the wet ground. Too much water also could flood crops.

“A large, slow-moving system is going to pose a lot of problems: winds, flooding, storm surge, and even potentially down the road, river flooding,” said Richard Knabb, director of the National Hurricane Center in Miami. “That could happen for days after the event.”

However, Isaac could bring some relief to places farther inland where farmers have struggled with drought. It also may help replenish a Mississippi River that has required dredging.

Forecasters predicted Isaac would intensify into a Category 2 hurricane, with winds of about 100 mph, by early Wednesday just before it makes landfall on the coast. The projected path took Isaac toward New Orleans on Tuesday and Wednesday, but hurricane warnings extended across 280 miles from Morgan City, La., to the Florida-Alabama state line.