Satellite, radar, and surface data indicate that Cristobal made landfall at 5 PM CDT between Grand Isle, LA and the mouth of the Mississippi River.
The National Hurricane Center has issued an update statement which can be found here.
Heavy rain, storm surge, and tropical storm force winds will continue to impact the central Gulf Coast from Louisiana to the western Florida Panhandle through this evening.
Heavy rain will spread inland across Louisiana and Mississippi tonight into tomorrow.