The Met Office has warned of the potential for flooding and travel disruption
The Met Office has issued an amber warning for heavy rain for parts of eastern Scotland during Storm Babet.
Forecasters say Aberdeen, Dundee, Perth, Stirling and surrounding areas could see unusually heavy rainfall from 06:00 on Thursday to 18:00 on Friday.
Up to 100mm (4in) is likely, with some upland areas seeing as much as 200mm (8in).
Network Rail Scotland said it was holding meetings to assess the potential impact.
Speed restrictions will be put in place from Aberdeen to Keith, Aberdeen to Dundee and between Perth and Inverness on Thursday, it said.
ScotRail said customers should check for updates on services before travelling.
The Scottish Environment Protection Agency (Sepa) has issued a number of flood alerts, with affected areas including Fife and Scottish Borders.
David Morgan, of Sepa, said the storm was expected be “relentless” in terms of duration and could last two or three days.
He told BBC Radio’s Good Morning Scotland programme: “The message just now is to be prepared and plan accordingly.
“But it’s important to stress that over the course of today, as our understanding starts to improve around the storm, the message might well change to be much firmer around really don’t travel.”
Mr Morgan added: “We are expecting it to be extremely wet.”
Traffic Scotland said there was a “high risk of disruption” to road travel in Angus, Dundee, Perth and Kinross, Stirling, Aberdeen, Aberdeenshire and Moray.
Transport Scotland said the forecast wet weather followed heavy rain and flooding over the weekend of 7 and 8 October.
Spokesman Stein Connelly said: “We recently witnessed some of the most severe weather in Scotland since the 1890s, and another wave of challenging conditions is expected this week.
“I would again ask the public to plan ahead and be prepared.
“Check before you travel as your journey is likely to be affected by these latest severe weather warnings – whether by foot, bike, car, rail or ferry.”
The Met Office has updated a number of yellow “be aware” warnings for rain and strong winds for most of the rest of Scotland for Thursday through to Saturday morning.
An earlier yellow warning for the east has been upgraded to amber and warns of the potential for travel disruption and flooding of properties.
The Met Office said: “It is increasingly likely that a period of disruptive, heavy and prolonged rainfall will affect parts of eastern Scotland.
“The heaviest rainfall is more likely to occur over Angus and southeast Grampian, although even lower lying areas could see unusually heavy rainfall during this period.
“Very strong southeasterly winds are likely to accompany heavy rainfall which may exacerbate impacts.”
Aberdeenshire, Highland and Shetland Islands councils have appealed to people to be prepared for the bad weather.
