Hurricane Irene is threatening to become one of the most impacting storms to ever strike the Northeast U.S., possibly striking major cities including Philadelphia, New York and Boston at hurricane strength late into the weekend.

After lashing the Bahamas on Wednesday, Irene is moving up the U.S. East Coast as a major Category 3 hurricane, packing winds of 115 miles per hour. Irene is centered about 65 miles east-northeast of Nassau, Bahamas and moving northwest at 13 miles per hour.

The first hurricane of the 2011 Atlantic season is posing an extreme threat to the U.S. East Coast -- with potential to become historic before it sweeps away from the U.S. mainland by late Monday or early Tuesday. 

Hurricane Irene is now a major Category 3 storm with maximum sustained winds of 120 miles per hour Thursday. The storm was located 735 miles south of Cape Hatteras, moving northwest at 12 miles per hour. The National Hurricane Center has issued a hurricane watch for northeastern North Carolina early Thursday morning as Irene churns up the coast toward North Carolina's Outer Banks. 

New York Mayor Michael Bloomberg is urging city residents to focus on potential damage Irene could cause, in a rare hurricane strength strike.

He met with city officials Wednesday preparing emergency plans. Forecasts suggest Irene could make a direct hit on New York late Sunday, raving the metro area with flooding, hurricane strength winds, downed power lines, power outages and downed trees and possibly broken winds and flying debris.

Things happen in the city, Bloomberg said, at a briefing after the city experienced an earthquake this week. Quite honestly, I am more concerned about our preparations for a hurricane that's approaching...Everyone should keep an eye on the storm and pay attention to the office emergency management when they put out some advisories on what we should prepare for as we get closer to the potential storm.

Early Thursday, forecasters are calling Irene an extreme threat with the potential to be a serious multi-hazard threat for the major metropolitan areas of the Northeast. And along the immediate coastlines, threats include storm surge, high winds, high waves and beach erosion.

In North Carolina, many residents and tourists of the Outer Banks are evacuating as the storms moves that way, with potential of a landfall.

There's going to be flooding, there's going to be heavy rain, said National Weather Service Meteorologist Mike Rusnak, in the Virginia Pilot. It's just a matter of the exact track because it's still two days out and it's still too early to try to figure out out what kind of numbers to give here.

Irene is threatening to become the first major hurricane to hit the U.S. East Coast since Wilma struck Florida in 2005. Hurricane Ike was the last storm to make U.S. landfall, in 2008.

The storm could strengthen Thursday to a Category 4, with 135 mile-per-hour winds, the National Hurricane Center said, but it will likely fall in strength once it climbs higher up the East Coast through colder water.

Weather Channel experts on Thursday morning called Irene's threat to North Carolina coastal areas and the high-population northeast corridor particularly threatening and it is best for people to be on alert.

Computer models have sharpened over the last 24 hours and the latest forecasts early Thursday show rare storm potency for portions of the Northeast. Irene is expected to approach the Carolinas late Friday night through Saturday, with Northeast U.S. impacts continuing into the weekend and early Monday of next week.

Models show high probability that Irene will reach the New York area, possibly making a direct hit, as hurricane strength, with winds in excess of 70 miles per hour. The storm is likely to hit New York's metro area by late Sunday night.

The governors of New York and Connecticut ordered agencies to make ready for the storm. In Rhode Island, officials plan to activate a 24-hour operations center, said Denis Riel, a spokesman for the Emergency Management Agency.

Hurricane Bill was the last hurricane to strike the tri-state New York area back in 2009 and only minor damage was reported. 

Nassau County Executive Ed Mangano on Wednesday warned residents to be prepared.

This is a good time to get prepared again in your homes, he said. There's items that you should stock up on, those that need to move or possibly be evacuated, perhaps seniors should think about having their medications refilled and having enough on hand.