The warning has been issued from 12 noon to 9pm.
The forecast predicts slow-moving heavy thunderstorms developing on Saturday afternoon in the warning area, which covers much of the central belt and the East Coast.
Met Office officials have warned that there is a change of fast flowing, deep floodwater that risks a danger to life.
There is a small chance that homes and businesses could be flooded quickly, with damage to some buildings from floodwater, lightning strikes, hail or strong winds.
It seems that the brunt of the weather may hit before the Rolling Stones take the stage.
According to forecasts, there is potential for 20 mm rain to fall in less than an hour with 30-50 mm possible in three hours.
Where flooding or lightning strikes occur, there is a chance of delays and some cancellations to train and bus services.
Drivers have also been warned that conditions could be difficult and there could be some road closures.
There is a slight chance that power cuts could occur and other services to some homes and businesses could be lost