The forecast focuses on Cornwall and the southwest of England, where droves of British eclipse-watchers will be heading, but also covers the entire path of the eclipse across the world.

The first forecast, issued on Sunday morning, is for a dry start to the day with sunny intervals across Devon, Cornwall and the Channel Islands.

The BBC's Julia Peet: Met Office only 40% confident of accurate prediction

Clouds are expected to gradually build during the morning with perhaps the odd shower developing by mid-afternoon.

As for the rest of the world, it suggests that from Cornwall to the western Black Sea, skies will be generally partly cloudy with a 60% chance of seeing the eclipse in any one location.

From the western Black Sea to southern Pakistan, skies should be largely clear, while from Pakistan to central India cloud increases significantly.

Cloud cover worries

Nasa has warned that England is one of the worst places from which to watch the eclipse, because of the likelihood of cloud cover obscuring the view.

Will it be obscured by cloud after all?

According to the US space agency, there is only a 45% chance of there being a clear sky above Cornwall at the right time.

The Met Office says the best and worse places, statistically, for clear skies within the area of the total eclipse are Torquay and Falmouth, which both have a 50% chance, and Princetown with just a 30% chance.

And Cornwall's eclipse co-ordinator Gage Williams says it does not matter if the skies are grey, anyway.

He said that if it was cloudy the eclipse could be even more spectacular, with people seeing a thin black line in the distance moving towards them "like an express train".

To listen to daily updated Met Office forecasts for the eclipse call 09003 50 04 99 - calls cost 60p per minute, or follow the Internet link at the side of this page.