Rain has started falling in Scotland with thunderstorms bringing lightning and flash flooding set to sweep across the country.
After days of hot, sunny weather with soaring temperatures for many, Scots are set for a washout.
A Tesco supermarket in Inverness was evacuated after parts of its roof collapsed in heavy rain.
The yellow warning for thunderstorms is in place for most of the mainland from 9am on Sunday and throughout Monday.
By Sunday afternoon, people were reporting thunder in the Highlands, and western areas of the country.
On Saturday morning, the Met Office updated its serious weather warning with storms to continue causing disruption across the whole of the UK on Monday.
Stormy weather could bring disruption in some places, alongside flooding, and some cancellation to trains and buses, while forecasters said up to 50mm of rain and hail could also fall.
It comes as temperatures in parts of Scotland almost hit 30C on Thursday and Friday.
Dyce in Aberdeenshire hit its previous August record of 29.7C set in 1995, while Craibstone set a new August record of 28.7C.
The Met Office forecast states: “During Sunday afternoon, cloudier conditions and areas of rain are expected to develop across parts of Northern Ireland and Scotland.
“A few places seem likely to see heavy downpours and thunderstorms, which could bring up to around 50mm of rain falling in 2-3 hours leading to some disruption.
“These may last through the night in places. Hail and frequent lightning are potential additional hazards.”
Insight Sean Batty STV Meteorologist
“There are concerns about water shortages in the farming community in the east of the country, and that’s no surprise given the massive rainfall deficit we’re clocking up here. Every single month this year so far has been much drier than normal, particularly for Aberdeenshire, Angus and the Borders.
“Not only is there a lack of rainfall, but consistently each month has also been warmer than usual which is helping to dry the ground out and also increases the risk of wildfires, and we’ve already seen some of those in Dunbartonshire and the Lothians.
“Some good news is on the way with rain coming in on Sunday and Monday, although will be far off what’s required, but could still lead to flooding issues.
“Currently our models are indicating that some of the wettest conditions will be around the north Highlands and Moray, but with thunderstorms so hit and miss it’s very tricky picking out specific areas at this lead time.
“Thunderstorms obviously come with their usual warnings of flash flooding, but after such exceptionally dry and warm weather, the ground is baked hard and this means when it rains initially there’s nowhere for that water to go, so that flooding can be worse.
“Saturday will still be a day of blazing sunshine and temperatures hitting 29-30C around Glasgow, Renfrewshire and Ayrshire, making it one of the warmest days of the year here. Even when the thundery showers develop on Sunday temperatures in many areas will still be in the 20s making it feel rather humid.
“As a side note, I get asked a lot what the smell in the air is after rainfall following dry conditions – this is called petrichor. Petrichor is made from bacteria which lives in the soil, and when rain arrives this is kicked into the air creating an earthy smell, which our noses are very sensitive too.”