HOUSEHOLDERS stayed up into the early hours of the morning to witness spectacular lightning displays across Scotland - after a week of rising temperatures.

Terrifying looking bolts of electricity struck the ground as rain cooled the humid conditions hours after the mercury had reached almost 30 centigrade.

It came as experts issued warnings to expect tornados in parts of the UK, including Scotland today, as the turbulent weather conditions continue.

The Tornado and Storm Research Organisation said the high pressure is "sufficient for organised severe thunderstorms including supercells, capable of large hail, damaging winds, and perhaps isolated tornadoes."

There were few reports of damage following lightning strikes which occurred overnight into Thursday morning north of the Border.

Tens of thousands of residents in the north-east of England were left without power after the storms passed through on its way to Scotland.

But despite the lateness of the hour, many Scots were awoken by the flashes and captured dramatic images on their smartphones and cameras.

One of the main areas affected was the north-east, with Aberdeen seeing forks of almost Biblical proportions.

Scott McKeand, 32, who took a picture of the display in the Granite City, said: "I was woken up by the first loud clap of thunder and noticed the flash of lightning. My first thought was to grab the camera and tripod."

In Dundee, the sudden change in conditions saw flashes of lighting hit the rooftops of city buildings and the River Tay, next to the construction site of the Victoria & Albert Museum.

Also affected were Edinburgh and the Lothians, Dundee, and the Scottish Borders, which saw torrential rain along with the thunder and lightning.

In Glasgow and the west, the night sky was lit up by the lightning as rain cooled the temperatures.

Amateur photographers captured spectactular images of the lighting in rural areas such as Humbie, East Lothian, and Kelso, in the Borders.

Leon Smith, meteorologist at the Weather Channel UK said the conditions would become more unstable on Friday evening, with "storms are likely to develop and become widespread. The storms are moving northwards overnight. We can expect flash floods, frequent lightning and some large hail."

Temperatures are expected to be around the mid-twenties centigrade on Friday, down from the high of 29.4C recorded in Moray on Wednesday.

He added there would be "strong and gusty winds too ahead of the storms."

Mr Smith said: "Saturday will turn out sunny and very warm to hot again across central to eastern England while thundery rain moves north from Scotland." Temperatures could again reach 30C in the south-east of London, potentially affecting conditions for players, workers and spectators at Wimbledon.

In England, which recorded the hottest July day ever on Wednesday, with temperatures of 36.7 C, more than 50,000 people in the north-east of the country had their power cut following storms.

A nursery owner in North Yorkshire watched as up to 5,000 greenhouse panes were smashed by giant hailstones and a house in County Durham lost its roof to a blaze, apparently following a lightning strike.

Giant hailstones caused damage to cars in the Yorkshire Dales and in areas of County Durham.

Scores of motorists pulled over to watch last night as another storm moved up The Pennines.

Leeds North West MP Greg Mulholland said on Twitter: "What an amazing spectacle of nature. I hope it's not like Day of the Triffids."