'Frankenstorm': More than just a name, Hurricane Sandy could be building to a perfect storm

Lawrence McGinty

Former Science and Medical Editor

Satellite pictures of hurricane Sandy from NASA Credit: NASA

OK, I admit it. They are calling it the "Frankenstorm" largely because it is happening just before Hallowe'en. But there is another reason - because Hurricane Sandy is a strange combination of circumstances that is leading to the perfect storm - just like Count Frankenstein's monster.

First, sorry, but a few basics. Tropical storms and hurricanes pick up their energy from the sea. Tropical seas are relatively warm - so the storm picks up heat from the ocean - just like you or me standing next to a radiator.

And the longer a hurricane's path over the ocean, the more energy it picks up. Hurricane Sandy has swept through the Caribbean - killing many people and causing devastation - and has picked up lots of energy on its way to New York. That is why they are recording wind speeds of 85 mph.

That is the first element in making Sandy unusually threatening. The second is to do with storm surges. As hurricanes come onto land, they pass over shallow water - and they push that water ahead of them - a bit like a Tsunami. They are predicting a storm surge of 11 feet in New York.

But here is the second element: that storm surge could be much worse because at 9pm tonight in New York it will be high tide - and not just any high tide, but the highest tide of the year - which occur in spring and autumn. So that 11 feet will be over a very high tide.

A man takes a picture while a wave crashes over the boardwalk in Ocean City Credit: Reuters

And the third element? A mass of cold air that is sitting over Canada and Greenland.

When the storm reaches that it will be like hitting a road block. It will force the storm westwards into the mainland instead of doing what tropical storms normally do, turn right into the Atlantic and die out because they cannot pick up energy from the colder waters.

This time though, the hurricane has turned left and is heading towards some of the biggest population centres in the world.