IT has made the summer a washout.

But an anticipated move in the jet stream is likely to spell only more misery for Scots.

The Met Office has already issued yellow weather warnings cautioning against a risk of flooding today across the bottom half of Scotland, Northern Ireland, Wales and northern England. Up to 80mm of rain is expected to fall in western areas as heavy, thundery showers sweep across the country. Forecasters warn that already saturated areas will be prone to flooding with motorists urged to take care as roads run the risk of becoming waterlogged.

It comes after an already dismal summer which has seen Britain drenched by the wettest April and June on record and the wettest April-June period on record.

However, forecasters are anticipating better weather on the horizon from the middle of next week for the south of the UK as a change in the course of the jet stream promises to bring improved conditions to the country ahead of the start of the Olympics.

The miserable start to the summer has been driven by the unusually southerly location of the jet stream, a high-altitude belt of wind which is now expected to move northwards towards Britain allowing Brits in the south of the UK to bask in warmer, drier conditions.

Unfortunately, it is not such good news for Scots crying out for a fresh heat wave as the movement of the jet stream will push areas of low pressure further north, bringing increasingly wet and windy weather north of the Border from Sunday.

A spokesman for the Met Office said: "The jet stream is going to be slowly moving north over the next few days, bringing back what we would consider more normal conditions to the UK.

"This isn't necessarily the best news for Scotland, although in certain areas like north-west Scotland – where there has been very little rainfall recently – they'll get some much needed rain from Sunday due to the change in the weather patterns.

"It's very much a return to normal, and unfortunately a normal summer tends to see the south-east of the UK enjoying drier, warmer weather, and the north-west being wetter and windier.

"The end of this week in Scotland won't be too bad – Thursday and Friday are quite decent and there will be dry and bright spells on Saturday, but as the low pressure moves in on Sunday it will bring rain."

The unseasonal drought in the north-west of Scotland was so bad that at one point it forced the Tobermory whisky distillery on the Isle of Mull to cease production because levels of water in the private loch it uses during manufacture had fallen below preferred levels. Production has since been restored, but the suspension was all the more surprising against a backdrop of flooding in parts of England.

Several areas experienced an entire month's rain in a single day, with the Environment Agency issuing flood warnings in 171 locations in England and Wales simultaneously earlier this month.