Ida's wind speeds appear to have reached a maximum at 150mph and so remains at category 4.
It has made landfall near Port Fourchon in Louisiana and secondly again at Lafourche Parish.
According to the NHC:
Hurricane-force winds extend outward up to 50 miles (85 km) from the center and tropical-storm-force winds extend outward up to 150 miles
A Storm Surge Warning is in effect for... * Intracoastal City Louisiana to the Alabama/Florida border * Vermilion Bay, Lake Borgne, Lake Pontchartrain, Lake Maurepas, and Mobile Bay A Hurricane Warning is in effect for... * Intracoastal City Louisiana to the Mouth of the Pearl River * Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans A Tropical Storm Warning is in effect for... * Cameron Louisiana to west of Intracoastal City Louisiana * Mouth of the Pearl River to the Alabama/Florida border
Port Fourchon is a major Louisiana oil centre - more information available here
According to Jeff Masters blog, New Orleans should be protected by its upgraded storm protections.
The different landing points of Katrina and Ida are in this Tweet