Communities hit by flooding earlier this year have been warned to prepare for further misery as a storm that battered the US arrives in Britain.

Forecasters have warned that the possibility of heavy rain on already saturated ground after the wettest December on record means more flooding is likely in many of the areas affected last month.

The Scottish Environmental Protection Agency (Sepa) has issued more than 45 flood warnings and alerts for regions across the country.

Dundee, Angus, Tayside, Argyll and Bute, Ayshire and Arran, Dumfries and Galloway and west central Scotland were worst hit. Aberdeen, Aberdeenshire, the Scottish Borders and Central Scotland are also under threat.

Weather warnings are in place across much of Scotland, including the Highlands, Strathclyde, Central, Tayside and Fife, Dumfries and Galloway and the Scottish Borders, and Grampian.

The Met Office has also issued severe weather warnings for heavy rain and severe gales, with forecasters predicting around 30 to 50mm of rain in most parts and up to 80 to 100mm in exposed upland areas. Parts of Scotland are likely to face winds of up to 70mph.

A second weather front will see further rain and wind hitting the UK towards the end of the week. But recent mild temperatures are expected to continue after one of the warmest January days on record on Sunday.

Several train services have been disrupted as a result of the severe weather.

Routes between Dumbarton Central and Helensburgh Central, Busby and Thorntonhall, and Glasgow Central and East Kilbride were all disrupted due to flooding on the tracks.

Services between Glasgow Queen Street and Oban were also affected. Heavy rain also forced the closure of the A85 Methven to A822 Gilmerton. All lanes were shut for more than an hour on Tuesday morning.

The A85 Crieff to Comrie road is impassable due to flooding and only tractors can pass.

Lochard road, the main route through Aberfoyle in Stirlingshire, has also flooded after the River Forth burst its banks.

Firefighters and the Trossachs Search and Rescue Team are in attendance, and police are directing traffic.

The Forth Road Bridge was closed to high sided vehicles, cars with trailers, caravans, motorcycles, bicycles and pedestrians. All lanes on the the A92 Tay Road Bridge are also restricted in both directions.

A passenger was injured in Edinburgh at around 9.45am after a chimney fell from a roof in the city's Nicolson Street and smashed through the window of a Lothian Bus.

A man was slightly injured in the incident and was treated at the scene by the Scottish Ambulance Service.

South Bridge will remain closed between Chambers Street and Nicolson Square until the affected buildings are assessed and made safe.

Inspector Norman Towler of Craigmillar Police Station said: "We have diversions in place along Chambers Street and anticipate this will be the case until later today. We are asking the public to avoid the area if at all possible meanwhile."

A spokeswoman for the firm said: "One of our passengers has been hurt due to falling masonry but thankfully has received only minor injuries."

Ayrshire College was forced to close its Ayr campus after part of the roof was blown off. All evening classes were cancelled on Tuesday.

Pupils and staff at a primary school were evacuated by boat after the building was cut off by flooding.

Danny Gibson, Stirling Council's environment convener, said: "Due to flooding on Lochard Road, Aberfoyle Primary School was closed and evacuated.

"Twenty-two pupils and staff, including 12 children, were evacuated with the help of fire and rescue service crews, who used a boat and two rescue sleds. We'll be working closely with our partner agencies to monitor the situation overnight."

STV weather presenter Sean Batty said the weather is the remnants of the storm that brought blizzards and near record-breaking amounts of snow to the US east coast.

He said: "Most people will have seen the pictures, and heard about the awful snowfall that hit the north east states of America on Sunday. The low pressure system that brought the snow has been crossing the Atlantic during Monday and will sweep north of Scotland on Tuesday.

"In Scotland we don't have to worry about snow, as the system has drawn in warmer air during its Atlantic crossing. It will bring heavy rain across much of the country on Tuesday morning, with the worst of it falling in the west.

"With water tables high after the very wet start to January, it's possible that western areas could see some localised flooding issues. It will give drivers a horrible commute to work with a lot of surface spray on the roads, meaning travel could take longer than usual.

"Strong winds will also accompany the rain, with gales or severe gales in western and southern parts of the country. This may lead to ferry disruption, particularly to North Channel and Irish Sea crossings, and some restrictions are likely on the bridges. Strong gusts can be expected in the east of the country.

"The weather will stay very unsettled throughout the week, with more rain on Wednesday moving north, with significant snow on higher ground. Some of the snow may come down to lower levels in the north of the country.

"After some exceptionally mild conditions on Sunday, when Achnagart in the Highlands set a new record for January, reaching 17C, the weather will turn colder later in the week. By Saturday hail, sleet and snow showers will affect most northern and western parts of the country."