LONDON, Feb 17 (Reuters) - The British government will invest 1.2 billion pounds ($1.6 billion) in what it says is the world's most powerful supercomputer to provide more accurate weather and climate forecasts.

The new supercomputer, which will be managed by the country's Met Office, will be used to help more accurately predict storms, select the most suitable locations for flood defences and predict changes to the global climate.

It will enable better forecasting for airports so they can plan for potential disruption and provide more detailed information for the energy sector so it can prevent potential energy blackouts and surges.

The Met Office's current supercomputers reach their end of life in late 2022. The first phase of the new supercomputer will increase the Met Office computing capacity by six times, the government said on Monday.

($1 = 0.7685 pounds) (Reporting by Nina Chestney; Editing by Mark Potter)