New York city Mayor Michael Bloomberg says the city has plans to close the entire NY metropolitan transportation system this Saturday, as concerns grow over the anticipated force of Hurricane Irene's arrival. It is expected to arrive in NYC as a Category 1 storm Sunday, with winds up to 90 mph and intense rains.

Mayor Bloomberg said Thursday that it was "very conceivable" that he will order a mandatory evacuation of all low-lying areas of the city by Saturday.

"The storm is predicted to be very dangerous," the mayor said.