Warm dry start predicted for Games

The UK is in for more rain as the jet stream moves south again, but forecasters say the weather for the start of the Olympics will not be as bad as it has been for much of the summer.

The wettest April to June on record and a rainy start to July were blamed on the jet stream being much further south than normal, bringing wet weather conditions that would usually bypass much of the UK.

After the high altitude band of wind which guides weather systems moved to a more normal position further north, the UK basked in a week of warm, sunny weather, but as the Olympics get going, forecasters say there is more rain on the way.

Aisling Creevey, forecaster at MeteoGroup, the weather forecasting division of the Press Association, said there was a lot of unsettled weather on the way, with the jet stream "flinging" weather systems towards the UK.

"What's happening is the jet stream is moving south and there's an 'upper low' - low pressure in the mid atmosphere - which is bringing quite a mobile weather pattern with fronts moving through and showers."

But she said: "I don't think it's going to be as unsettled as it was. The last we had was very widespread, but this particular spell of unsettled weather is quite mobile, just affecting different areas at different times."

She said Scotland and the south west were likely to see the worst of the rainy weather, with the potential for some heavy, thundery showers across Scotland. But the weather would not be as disruptive as the last period of wet conditions, which saw flooding across many parts of the UK.

As Olympic sporting events get going in earnest over the next few days, the picture is mixed in London and the south, with drier weather conditions on Saturday and Monday, but the possibility of frequent showers on Sunday.

The wet weather is likely to hit northern areas first and then spread south, and by Wednesday, it will be unsettled everywhere. But Friday's opening ceremony is expected to escape the rain.

London will be most at at risk of rain on Friday morning and early afternoon, but experts said the showers should have cleared by 9pm when the eagerly awaited £27 million showpiece gets under way.