Sandy is classified as a Hurricane 1 status, a low-grade hurricane. However, don't let that fool you in terms of impact. It's not the absolute magnitude of the hurricane, but rather the magnitude vs. what the infrastructure can handle that matters.
Barometric pressure is 27.76, the lowest pressure recorded for a storm in the Northeast. Sandy is unprecedented in size as well. The hurricane is likely to reach shore with a full moon high tide raising storm surges several more feet.
Accuweather notes "The storm surge will reach generally 5-10 feet with up to 15 feet possible in a locations along and to the north of where the center makes landfall. When a 2-foot tide this evening is combined with 10- to 20-foot wave action, water will reach more than 30 feet above sea level in places. ... Total damage from Hurricane Sandy may well exceed Katrina's $96 billion. This could be the first $100+ billion storm in U.S. history."
New Jersey, New York, Washington DC, West Virginia, Pennsylvania, Maryland, Vermont, and Connecticut have all declared states of emergency. Parts of New Jersey are under mandatory evacuation. At least 60 million people will be affected.
New Jersey and New York City face for very dangerous conditions and catastrophic damage. As of 2:40 p.m. EDT Monday CNN, nearly 300,000 customers are without power in seven states. New Jersey has the most at 92,000. Over 7,000 flights have been cancelled.
Damaging and life-threatening impact from the giant, powerful storm will reach as far inland as the central Appalachians and will span the coast from North Carolina to southern New England.
The record tide gauge in Atlantic City New Jersey is 9.0 feet. Sandy is at 8.25 feet now, and a near-lock to surpass the previous high, perhaps by many feet. Moderate to major flooding is already occurring in the Chesapeake Bay.
The Chesapeake Bay near Kiptopeke, Va., is at major flood stage of 5.95 feet, less than one foot below the record high of 7.1 feet set on March 7, 1962.
The Chesapeake Bay Bridge Tunnel, Va., is at 6.71 feet. This is also only 1 foot below the record flood stage of 7.5 feet set on Sept. 18, 2003.
In the Appalachian mountains, blizzard whiteout conditions with as much as two feet of snow are expected.