By Lucy Ashton
The Met Office has issued a yellow warning affecting much of the west coast and Highlands from 12:00 until 21:00 BST on Sunday.
Forecasters said conditions would include lightning strikes, strong winds and “torrential” rain in some parts.
Further warnings for thunder affecting the north east and Dumfries and Galloway are in place for Monday.
Again these will last between 12:00 and 21:00 BST.
The areas experiencing the worst rain could see 30-40mm in an hour.
Earlier this week the Scottish Fire and Rescue Service issued a Scotland-wide warning of a “very high” wildfire risk, which remains in place until Saturday.
A wildfire near Cannich in the Highlands had been burning for almost two weeks and caused extensive damage to an RSPB Scotland nature reserve.
Meanwhile the Scottish Environment Protection Agency (Sepa) has reiterated warnings on water scarcity.
Its most recent report on Thursday said the issue was most acute around Loch Maree in Wester Ross, increasing the risk in the area to “significant”.
The agency also said Loch Ness – Scotland’s largest freshwater loch by volume – had dropped to its lowest water level in 32 years last month amid dry conditions.
Top picture: Water levels in the River Leven at Renton are low given the high temperatures.