US east coast residents prepared overnight for one of the most powerful storms in recent memory as Hurricane Isabel whirled through the Atlantic toward possible landfall in North Carolina.
Isabel's top winds weakened slightly to 125 mph as it took a path that could bring it ashore near Cape Hatteras, North Carolina, and north along the Chesapeake Bay near Washington DC, through Virginia, Maryland and Pennsylvania, the US National Hurricane Center said.
Although its track was uncertain, it could affect millions of people in some of the most heavily populated areas of the Eastern Seaboard including Richmond, Virginia, Washington DC, Baltimore, Philadelphia and parts of New Jersey.
The Virginia Department of Emergency Management issued its first Isabel warning and encouraged citizens to prepare to evacuate if necessary.
Isabel's sustained winds, which fluctuated as it moved through the open Atlantic, were at 125 mph, putting it at Category 3 on the Saffir-Simpson scale of intensity. Such a storm is capable of tearing roofs off houses and can raise tides 9-12 feet above normal.
Isabel has reached Category 5, the top of the Saffir-Simpson scale with sustained winds above 155 mph, several times in the past few days.
The last big storm to hit North Carolina was Floyd, which caused massive flooding in 1999. Floyd ended up killing 56 people and causing $4.5 billion in damage, the third-costliest hurricane in US history.