During the 2008 North Atlantic tropical storm season the Met Office is forecasting 15 named storms, with a 70% chance that the number will be in the range 10 to 20 between July and November. This represents above-normal activity relative to the 1990-2005 long-term average of 12.4, and is more than last year's total of 12 storms for the same period.

Go to the forecast

The Met Office forecast uses an ensemble of global climate model forecasts which simulate the interactions between ocean and atmosphere. These forecasts successfully predicted the switch between the very active 2005 season to the much quieter conditions the following year. The forecasts use a radically different approach to traditional statistical methods which rely on past trends and have been developed following research work with other European prediction centres.

Matt Huddleston, Met Office Principal Consultant on climate change says: "North Atlantic tropical storms affect UK citizens abroad, and at home through fluctuating oil, food and insurance markets. The Met Office forecast has already demonstrated its benefits over traditional methods, especially in highlighting extremes. This year the range is very interesting and is the result of competing influences from the Atlantic and Pacific. While warm sea temperatures in the Atlantic act to increase the number of storms, our model also captures the small potential of an El Niño in the Pacific which may counteract this, hence the wider range in our forecast compared to others."

The Met Office also provides forecasts of tropical storms and hurricanes ranging from individual short-range track and landfall projections which are used by the National Hurricane Center in Miami.

Notes:

• The Met Office Public Weather Service funds the basic tropical storm frequency forecast for the Atlantic's June-November season in support of its activities on behalf of the FCO.
• The forecast is for the five full months remaining in the June-November Atlantic tropical storm season. There has been one named storm to date – Arthur.
• An ensemble means predicting the future many times to sample the possibilities. As the climate is chaotic, and small changes in the initial conditions make big changes in the forecasts, this is one approach to get risk-based estimates of the impacts of weather and climate.
• Tropical storms represent significant risk to the insurance, energy and finance markets. In 2005, Lloyd's estimated its losses to be £2.9 billion as a result of the three biggest hurricanes alone in the Atlantic season. The impact of Hurricane Katrina on oil and gas production was hugely significant for UK and global markets.
• A detailed report on the 2008 forecast will be available from the Met Office on 26 June with information on probabilities and the strength and credibility of signals within the forecast. To receive the report please email consulting@metoffice.gov.uk or contact our 24-hour customer centre.