Sepa has issued flood alerts for Dundee, Angus, Perthshire and Fife after the Met Office issued a thunderstorm warning.
The Met Office has activated a yellow warning between 7pm tonight and 10am Saturday for the whole of Courier Country.
The warning says that heavy showers and thunderstorms will bring difficult travelling conditions and localised flooding.
Sepa says the heavy rain poses a threat of flooding across the region.
The flood alerts says: “Thundery showers during Friday evening and early Saturday morning give a risk of flooding from surface water.
“Particularly at risk are urban areas and the transport network. Due to the localised nature of the showers, impacts may be isolated with not all locations being affected.
“There is a possibility of further thundery showers during Saturday afternoon that may lead to minor localised surface water impacts.”
The Met Office warning says: “There is a good chance driving conditions will be affected by spray, standing water and/or hail, leading to longer journey times by car and bus.”
It adds that delays to train services are possible, short-term loss of power and other services is likely.”
There will “probably some damage to a few buildings and structures from lightning strikes” and “some flooding of a few homes and businesses is possible, leading to some damage to buildings or structures”.
