The Met Office forecasts 15 tropical storms could develop in the North Atlantic between July and November this year, above the long term average of 12.4 storms, it said yesterday.

Britain's official weather forecaster said there was a 70 per cent chance of the number of tropical storms in the area being between 10 and 20 this season, with 15 the most likely.

The forecast for this year is for more frequent stormy weather in the North Atlantic basin - which includes many oil fields in the Gulf of Mexico - than last summer.

Last year, the Met Office said there was a 70 per cent chance that between seven and 13 tropical storms - cyclones with mean wind speeds of over 39 miles an hour - would develop in the region and put the most likely number of storms at 10.

In the end there were 12, just below the average of 12.4 for the years from 1990-2005 and half the number seen in 2005, the year Hurricane Katrina devastated New Orleans in the US and parts of the Caribbean.