After Hurricane Irene makes landfall in New England, it will weaken, as it continues northwards [Reuters]
Irene is still a category one hurricane as it batters the east coast of the US.
To be classified as a hurricane the winds need to be over 119kph (74mph), and Irene is comfortably over that, with winds of 130kph (80mph).
New York is one of the places that will see these hurricane-force winds, and the winds will be picking up in the coming hours. By sunrise, there are likely to be winds gusting up to hurricane-force in strength, and by midday (1700GMT) the winds are likely to be sustained hurricane-force winds.
Winds this strong are likely to bring down power lines and trees, but it is the amount of rainfall that is likely to be a main problem.
It is a huge storm, which covers a vast area and currently measures around 1,500km from north to south. The hurricane-force winds are actually in a very small portion of the storm, but the rain is heavy and extensive.
The storm is moving very slowly, only around 28kph (17mph), which means that it will only pass slowly. The most rain that has been reported so far was 45cm (18 inches) in Bunyan, North Carolina.
The rain is now clearing away from North Carolina, but to the north, it will stay heavy and prolonged for several hours. The mid-Atlantic states, eastern New York and inland parts of New England are all likely to experience flooding, which will be made worse by the weather which has been seen in the past few weeks.
Recently there has been a lot of rain in the northeast of the US, so the ground is already pretty saturated in some spots. This will exacerbate the flooding, and there's also the risk that the rain-softened ground could lead to the uprooting of trees.
Along the coast, water levels are rising rapidly from Maryland to New York. A storm surge of 1.13 metres (3.7 feet) has been observed at Lewes in Delaware, and 1.07 metres (3.5 feet) in New York's harbour. There is the risk that the surge could be as much as 2.5 metres (8 feet) in some areas, and on top of that, large, destructive waves.
Any storm surge we see in the evening will be accompanied by high tides, which are higher than average this weekend. If this high tide happens simultaneously with the storm surge, this would obviously lead to higher water levels and more coastal flooding.
After Hurricane Irene makes landfall in New England, it will weaken, as it continues northwards.
By the time the storm crosses the border into eastern Canada on Sunday night, it should be just a vigorous area of low pressure. This means that the weather in Canada will not be as bad as that in the US, but there are still warnings in force in the country for heavy rain, strong winds and a storm surge for coastal areas.
The Canadian Hurricane Centre is warning that a shift in the exact track or intensity of the storm is unimportant, as Irene is such a large system with far-reaching impacts. Residents are urged to start making preparations immediately.