Hurricane Sandy could bring a "life-threatening storm surge" with high-speed winds, rain and snowfall up to 3 feet in depth, according to America's National Hurricane Center.

Sandy, which has been declared a Category 1 hurricane, denoting severe strength, is expected to make landfall on America's east coast within hours.

The impact zone will encompass the key cities of Boston, New York and Washington DC, and the storm is also likely to afflict large tracts of Delaware, Virginia, North Carolina and New Jersey.

The National Oceanic and Atmospheric Administration (NOAA) has dubbed Sandy as the largest storm ever to hit the United States. One meteorologist has dubbed it 'Frankenstorm', in the belief that it will conflate with a wintry storm from America's north-east to pose an even bigger threat.

The NHC has forecast rainfall of up to 12 inches, with snowfall of between 2 and 3 feet in the mountains of West Virginia, Western Maryland and North Carolina.

Meanwhile researchers at United States Geological Survey (USGS) have warned that the storm could erode many Atlantic beaches, bringing a dramatic change in the coastlines of Delaware, Maryland, Virginia and Long Island, NY.

"Nearly three quarters of the coast along the Delmarva Peninsula is very likely to experience beach and dune erosion as Hurricane Sandy makes landfall, while overwash is expected along nearly half of the shoreline," the USGS said in a statement.

A state of emergency has already been put in place in New York, while other cities have shut down key functions including schools, offices and public transport.

Tens of millions of east coast residents were reportedly evacuated over the weekend to brace for the arrival of Sandy, which has already killed 66 people in the Caribbean.

As Hurricane Sandy makes landfall on Monday night or Tuesday morning across the US East Coast, Nasa satellites have captured the intensifying storm from space. Check out the pictures below.

Hurricane Sandy Satellite Images
NOAA's GOES-13 satellite captured this image of the massive Hurricane Sandy, with a line of clouds from the Gulf of Mexico demonstrating the cold front Sandy is merging with. NASA GOES Project
Hurricane Sandy Satellite Images
This image, ccombining NOAA's GOES-13 and GOES-15 satellite imagery on Oct. 27, shows the cloud cover from Hurricane Sandy coalescing with the band of clouds from the north-eastern cold front. NOAA/UWI/SSEC
Hurricane Sandy Satellite Images
This visible image, taken from NOAA's GOES-13 satellite on Friday, Oct. 26, shows Hurricane Sandy's huge cloud extent of up to 2,000 miles while centered over the Bahamas. NASA GOES Project
Hurricane Sandy Satellite Images
On Oct. 25, NASA's TRMM satellite observed that rain at the centre of Hurricane Sandy was moderate (in green and blue) and falling at a rate of 20 to 40 mm per hour. SSAI/NASA, Hal Pierce
Hurricane Sandy Satellite Images
The heaviest rainfall at the time of this image was falling over the Dominican Republic at more than 2 inches/50 mm per hour (red). SSAI/NASA, Hal Pierce
Hurricane Sandy Satellite Images
Early in the morning on October 25, 2012, the Suomi NPP satellite passed over Hurricane Sandy after it made landfall over Cuba and Jamaica, capturing this highly detailed infrared imagery. NOAA/NASA
Hurricane Sandy Satellite Images
On Oct. 23, the MODIS instrument captured a visible image of Tropical Storm Sandy when its center was a couple of hundred miles south of Jamaica. NASA/MODIS
Hurricane Sandy Satellite Images
A 3-D perspective of the developing tropical depression (L) taken by NASA's TRMM satellite on 18 Oct, showed powerful storms near the centre were reaching altitudes of over 14 km. The picture on the right is a visible image of Tropical Depression 18 taken from NOAA's GOES-13 satellite on Oct. 22, just before it was classified as a depression. NASA
NASA Storm New York