President Barack Obama has warned the country that Hurricane Irene, currently looming off the east coast of the US, could be a historic storm. The warning is in continuation of a storm building up above the east coast and waterfront areas around the tip of Manhattan which are among the most vulnerable in New York. He was on a holiday in Martha's Vineyard, an island on the Massachusetts coast, headed home from his break one night early.

Scientists and Air Force reserve pilots, daring a 100MPH winds, flew deep into the eye of hurricane Irene in order to assess the storm’s intensity. They shot canisters filled with sensors into the ferocious storm clouds. As per reports Irene's pressure was dropping, which meant that the storm was getting stronger due to the warm ocean waters below. The category II storm has weakened a little and is expected to make landfall with winds of up to 100mph (155km/h). Irene, had already caused havoc in the Caribbean.

North Carolina, Virginia, Maryland, Delaware, New Jersey, New York and Connecticut have all been placed under states of emergency. Washington DC Mayor Vincent Gray declared an emergency in the US capital.

Michael Bloomberg New York City Mayor has issued the city's first-ever mandatory evacuation notices, as the US faces up to the arrival of Hurricane Irene.

New York City’s transport systems, including the subways and airports, are shut from 12:00 on Saturday (16:00 GMT). Amtrak, the US rail network, announced cancellation of services between Washington and Boston from Saturday, in addition to earlier suspended operations from south to Virginia and beyond. The American Red Cross was preparing dozens of emergency shelters along the east coast.