Rivers are at risk of overflowing and roads across Tayside and Fife have been left impassable as heavy rainfall batters the region.
The Scottish Environment Protection Agency (Sepa) has upgraded an alert for parts of Tayside and issued five flood warnings for the area.
Water levels on the River Earn are expected to be extremely high overnight with land neighbouring it at risk.
A flood warning has also been issue for Comrie with the Water of Ruchill said to have overflowed on to a field neighbouring the flood defences at Dalginross.
Sepa flood warnings are also in effect for the following areas: Innerpeffray to Bridge of Earn, Glen Lyon, Crieff to Innerpeffray, Carse of Lennoch to Lochlane, and Bridge of Ruthven to Leitfie.
On Friday evening a flood warning was issued for Arbroath town centre.
Sepa say Hume Street, Brothock Bridge, Old Shore Road, Dens Road, Lindsay Street, Lady Bridge and Marketgate are the areas most at risk.
The Barry Burn in Carnoustie is also said to have burst its banks.
The A85 Lochearnhead to Perth road is also said to be badly affected by flooding.
Parts of St Andrews have also been hit by the downpour with water covering routes.
The town’s famous Old Course has been forced to close due to the weather.
?ANNOUNCEMENT: The Old Course is CLOSED due to adverse weather conditions.
— St Andrews Links (@TheHomeofGolf) August 9, 2019
St Andrews is currently experiencing a yellow warning storm and it's getting pretty crazy on the courses.
Pictured below, the Swilken River just about ready to overflow ? @TheHomeofGolf #Golf #StAndrews pic.twitter.com/GjcASBkm7P— Scotland for Golf (@ScotlandforGolf) August 9, 2019
@trafficscotland serious flooding just after comrie southbound on the #A85 both lanes affected passable just by cars
— liam Richardson (@TaysideEvp) August 9, 2019
The Sepa flood warning for Comrie states: “A flood warning has been issued for Comrie. River levels are continuing to rise on the Water of Ruchill.
“Floodwater has encroached on to the field adjacent to the flood defences at Dalginross.
“The access road to Tomnagaske is at risk of flooding. Further updates will be issued when appropriate.”
Police say they have been made aware of flooding on South Crieff Road, Comrie.
Reports of localised flooding in parts of #StAndrews causing problems on roads. @fifeweather @metoffice pic.twitter.com/Q6ivDZfELx
— Michael Alexander (@C_MAlexander) August 9, 2019
The force added that they have received a number of reports of flooding on roads across Tayside, with Angus said to be the worst hit area.
Dundee Street, Arbroath Road and Bruce Drive in Carnoustie are among the routes affected; along with Montrose Road, Tarry Road and Nolt Loan Road in Arbroath.
In Dundee police say Arbroath Road and Forthill Road, Broughty Ferry, were the worst affected.
A statement from Tayside Police Division reads: “As you would expect with the current weather we’re experiencing, we are receiving a lot of reports of localised flooding on roads, Angus in particular.
“Also, all major routes are experiencing issues with surface spray. This should not be a problem if everyone drives sensibly and according to the conditions.”
Earlier on Friday a huge tree fell on to an Angus road, leaving it blocked.
The incident took place on the A932 Friockheim to Forfar road near Pitmuies Gardens at about noon.
Heavy rainfall and a forecast for thunderstorms led to a number of events across Tayside and Fife being cancelled.