The Caribbean area has already had a visit from Alex this summer, and is hoping very much that Bonnie and Colin aren’t following close behind.

There would be real concern if Walter arrived as that would be the 21st named hurricane of a season that begins in June and peaks in September, though it would still be short of the 28 storms that battered the area in 2005.

Hurricanes, called typhoons in the Pacific and Indian Oceans, are intense areas of low pressure with rapidly rising air that are much stronger than the ’depressions’ we get.

Starting as tropical storms, by the time they are Category 5 they can be terrifying weather systems, with winds up to 160 mph, intense rainfall and great storm surges in coastal areas. Big ones can measure more than 500 miles across and move very slowly.

They are real testimony to the energy in our atmosphere, and a Category 5 is the equivalent of more than 200 times the global electricity production or a ten-megaton nuclear bomb every 20 minutes.

All this energy is simply because of what happens when water evaporates. It starts early in summer, a little distance from the equator, when the sea surface temperature is more than 26 degC.

The sun evaporates the water, which rises with the warm air, taking the energy with it. Because of the rotation of the Earth, this low pressure system begins to spin, counter-clockwise in the northern hemisphere.

Because it is colder higher up, the rising air cools, so some of the water vapour condenses, giving off all that extra heat of evaporation.

This keeps the air rising, so dragging in more wet air at the bottom until a very serious low pressure is formed, and a tropical storm can develop into a Category 5 hurricane as long as it is over warm sea water.

Once it hits land, the source of energy is cut off and it will fill in and die within days.

Last year there were only three major hurricanes in the Caribbean area, but this year conditions are different and the expectation is that it could be very challenging.

The first half of the year has seen the highest sea surface temperatures ever recorded, and it is likely that there will be less wind shear high up, allowing the hurricanes to develop properly.

Strong winds seem to be related to the El Nino condition in the Pacific and, over the last few months, it has almost completely faded away.

It is unlikely that there will be more hurricanes with climate change, though they could well be more vigorous if the last 30 years are anything to go by.