North Carolina has declared a state of emergency as Hurricane Irene approached the East Coast Thursday.  Governors in Virginia, New Jersey, and Maryland also declared states of emergency.  Mandatory mass evacuations are being held in vulnerable coastal areas.

The 115 mph Category 3 storm is expected to hit North Carolina's Outer Banks Saturday afternoon.  The hurricane will then creep up the Eastern Seaboard. 

Emergency officials have issued an evacuation order for more than 200,000 tourists in three counties along North Carolina's coast.  Ocracoke Island on the Outer Banks is already evacuating.

Meanwhile, Ocean City, Maryland has announced mandatory evacuations, which will begin at midnight. 

States are preparing funds and resources to initiate relief operations in Irene's wake. 

The Federal Emergency Management Agency told residents along the East Coast to prepare supplies and emergency escape routes. 

The storm's exact path remains unclear. 

The core of the hurricane will continue to move over the northwestern Bahamas today, and pass well offshore of the east coast of central and north Florida tonight and early Friday. The hurricane is forecast to approach the coast of North Carolina on Saturday, the NHC said.

From a flooding perspective, this could be a hundred-year event, New Jersey Governor Chris Christie told CNN.  The biggest concern is getting people to pay attention and make sure they are ready, Federal Emergency Management Agency Administrator Craig Fugate told the station.

This is everything a hurricane can be, and it's on one of those worst-case tracks for the East Coast, NSH spokesman Dennis Feltgen said.  Usually, hurricanes that get up into the higher latitudes are fast-moving.  This one isn't - which means it will be a powerful, slow-moving storm that could be doing a lot of damage, he added.