Hurricane Irene is shaping up to become the U.S. east coast storm of a lifetime. Officials say Irene poses an extreme threat to areas from North Carolina to to southern New England through the end of the weekend. The major Category 3 storm has the potential to further strengthen before making landfall, and major metropolitan areas from Norfolk to New York and Boston face a threat of rare storm potency. 

As millions of residents up and down the U.S. east coast flocked to grocery stores, stocking up on food staples, batteries, and portable lights and generators, Irene continued to plod toward the Carolinas as a potentially devastating storm. Flights were being canceled in North Carolina and residents were being evacuated from the Outer Banks and other exposed, low-lying coastal areas.

This is everything a hurricane can be, and it's on one of those worse-case tracks for the East Coast, Dennis Feltgen, a spokesman for the National Hurricane Center, told NPR.

States of emergency were declared Thursday from North Carolina and Virginia to New Jersey and New York as officials planned for what was shaping up as an east coast storm for the ages. New Jersey Gov. Chris Christie called approaching Hurricane Irene a serious, significant event.

Irene, packing winds in excess of 115 miles per hour with hurricane force winds extending far from the eye, is threatening to become the first major hurricane to hit the East Coast since Wilma struck Florida in 2005. Hurricane Ike was the last storm to make U.S. landfall, in 2008. And Irene is no small matter, powerful in size and force.

North Carolina was under a hurricane watch late Thursday, and emergency officials were expanding evacuation orders to include more than 200,000 tourists and locals in three coastal communities in the Outer Banks.

Major Hurricane Irene poses an extraordinary threat and is one that no one has yet experienced from North Carolina to the mid-Atlantic to the Northeast to New England, the Weather Channel said.

Irene will make its closest approach to North Carolina by late Friday night and heavy rainfall is possible as far west as central North Carolina and north-central South Carolina. The storm is likely to remain at Category 2 strength or stronger by Sunday as it moves up the east coast, possibly making a direct hit in New York City, America's largest metropolitan area.

The last big hurricane to hit New York was in 1938, when a Category 3 storm struck Long Island.

But that historic event could be rivaled by Irene, poised to arrive in the northeast by late Sunday at hurricane force, with winds possibly in excess of 100 miles per hour. Major metropolitan areas like New York are facing threats of flooding, downed trees and power lines and major power outages.