Atlantic set for fewer storms

Friday 01st Jun 2012 by theWeather Club

This year's Atlantic tropical storm season may see a marked change from last year, with far fewer storms predicted in a Met Office forecast.

The tropical storm forecast is produced using the Met Office's seasonal prediction system called GloSea4. The model has better representation of the complex physical processes that cause tropical storms and hurricanes to form, which improves the accuracy of the forecast over previous models. The forecast also uses information from the seasonal prediction system of the European Centre for Medium-Range Weather Forecasts.

The 2012 season, which runs from June to November, is predicted to see somewhere between 7 to 13 tropical storms - with a most likely number of 10. This is less than the 1980-2010 average of 12 storms and marks a change from the past two years, which have both been particularly active with 19 storms each.

The Accumulated Cyclone Energy index - which measures the number of storms and their combined strength - is also likely to be slightly lower than average this year, with a most likely value of 90 compared to the 1980-2010 average of 104.

There is a relatively wide range in the ACE index for 2012, with a 70% chance that the number will be between 28 and 152. This is partly due to the current uncertainty in the evolution of the El Niño/La Niña cycle over the next few months.

Joanne Camp, climate scientist at the Met Office, said: "El Niño conditions in the Pacific can hinder the development of tropical storms in the Atlantic, so how this develops will be important for the storm season ahead - particularly from August onwards, which is normally the most active time for tropical storms."