Forecasters warn of blizzard conditions

After one of the mildest and greyest Christmases on record, forecasters are predicting that 2008 will start with a wintry snap, bringing travel chaos across parts of Britain as icy, north-easterly winds send temperatures plummeting to as low as minus 10C.

Snow and sleet is expected in eastern parts of Britain where temperatures are likely to be around freezing point from Thursday onwards.

The Highways Agency said hundreds of gritting lorries were already on stand by to combat blizzard conditions and keep roads passable as the country returns to work after the extended Christmas break.

The Met Office said a static area of high pressure over Scandinavia and a low over the south and south west of the UK would suck in very cold air from the east. But people in the west of Britain will remain largely unaffected by the chill. Prevailing winds are expected to switch back to the Atlantic after the weekend, bringing milder temperatures.

The Met Office's head of forecasting, Brian Golding, said: "After a mild Christmas and New Year, we will notice a real change to some cold and wintry weather. We will need to be prepared and wrap up well against the cold weather as we head back to work."

Tens of thousands of revellers were preparing to see in the New Year at Edinburgh's celebrated street party last night, confident that that there would no repeat of the high winds and rain which forced last year's event to be cancelled.

Temperatures were expected to be relatively mild for the time of year ranging from between 7C in Edinburgh and Glasgow to 6C as far north as Aberdeen.

With every turn of the weather seized on as evidence of global warming all eyes will now be on 2008 to see what the year brings. All 10 warmest years have been recorded since 1997 and last year's average global temperature is expected to be confirmed next week at 14C, making it the fifth warmest since records began in 1880.

But scientists are currently monitoring the effects of La Niña, an ocean- cooling phenomenon in the eastern Pacific, which is expected to produce a slightly cooler year globally, though with the underlying trend still upwards.

According to the National Oceanic and Atmospheric Administration in the US, classic La Niña conditions developed during late 2007 the first time it has been so pronounced since 1989. By the end of November, sea temperatures in the region were 2C below average with the wider effects likely to be felt well into 2008.

Although Britain is thought to be largely unaffected by La Nina, whose better-known cousin El Niño brings violent storms across the southern hemisphere, a long and sustained cooling in the Pacific this year will have dramatic effects on the world's weather and on food prices. A prolonged drought in the US threatens corn yields and could push global cereal prices to new record highs.