NEW ORLEANS — Hurricane Nate came ashore at the mouth of the Mississippi River on Saturday and pelted the central Gulf Coast with wind and rain as the fast-moving storm steamed toward the Mississippi coast, where it was expected to make another landfall and threatened to inundate homes and businesses in vulnerable low-lying areas.Nate was expected to pass to the east of New Orleans, sparing the city its most ferocious winds and storm surge. And its quick speed decreased the likelihood of prolonged rain that would tax the city's weakened drainage pump system. Still, the city famous for all-night partying was placed under a curfew, effective at 7 p.m., and the streets were not nearly as crowded as they would be on a typical Saturday night.Cities along the Mississippi coast such as Gulfport and Biloxi were on high alert.