Thunderstorms are expected to strike across Scotland on Friday and Saturday.
The Met Office has issued yellow weather alerts, with Scots urged to prepare for travel disruption and flooding.
Heavy rain is expected to drench the north-east between 12am and 2pm on Thursday.
The likes of Montrose, Stonehaven, Aberdeen, Inverurie and Keith are likely to see most of the downpour.
Thunderstorms are expected to start at around 4am on Thursday and will last through the day. The warning stretches from the Scottish Borders right up to the Highlands.
On Saturday, the whole country has been put on high alert for the thundery showers. The yellow warning starts at 4am and ends at midnight.
Experts have warned of potential damage to buildings as a result of floodwater, lightning strikes, hail and strong winds.
Spray and sudden flooding could also lead to difficult driving conditions and road closures.
The Scottish Environment Protection Agency (Sepa) has also issued 12 flood alerts.
Friday weather alerts
- Rain warning: 12am to 2pm
- Thunderstorm warning: 4am to 11.59pm
Saturday weather alert
- Thunderstorm warning: 4am to 11.59pm.
STV Weather presenter Philip Petrie said: “So far this week things have stayed fairly settled, with even some dry and bright conditions on offer. Even today started relatively dry with sunny spells in the east through the morning.
“Unfortunately, things are turning more unsettled from the west today as we have low pressure taking control of the weather.
“This low pressure is not going anywhere fast and will gradually move eastwards over the weekend giving us cloud, heavy rain, scattered showers – thundery at times, and windier conditions.
“This is why the Met Office has issued a series of yellow weather warnings for certain parts of the country over the next couple of days.
“Tomorrow looks set to be wet and miserable for much of the country – lots of rain which will be slow moving but turning showery through the afternoon.
“Some of those showers will be heavy and possibly thundery so we have the thunderstorm warning covering parts of Angus, Fife, Falkirk, Perth and Kinross, Stirling, Aberdeenshire and the Highlands.
“The showers could also band together to create longer spells of rain, particularly around the north east, so we have a rain weather warning in force through tomorrow morning and into the early afternoon covering Angus, Aberdeen and Moray – here we could see between 40-60mm on higher ground.”