Weather presenter Christopher Blanchett said a large number – about 32,000 – lightning strikes had taken place across Scotland in the past 24 hours.
The thundery weather comes after Scotland recorded its hottest day of the year on Thursday, with temperatures peaking at 31.2C in Threave, Dumfries and Galloway.
High temperatures meant that some areas in Scotland officially experienced a heatwave – with temperatures peaking at 25C or above for three consecutive days.
Blanchett said the several days of strong June sunshine and extreme heat had left a lot of energy in the atmosphere.
“A nearby cold front has moved in causing a highly unstable atmosphere,” he explained.
“The heat near the ground has been forced up into the freezing layers of the troposphere, cooling rapidly and creating giant cumulonimbus clouds and thundery downpours.”
He added: “Flash flooding can become a problem because the ground remains temporarily hot and baked solid meaning these sudden, intensive downpours cannot easily soak into the earth, drastically increasing the immediate flooding risk.”