Much of Scotland is threatened with more thundery downpours tomorrow while part a key ScotRail scenic line will be shut for a week or more after the ground was washed away from under the track.
More than 1,000 tonnes of material have been dislodged by heavy rain near Crianlarich, closing the Glasgow to Oban and Mallaig line between there and Ardlui at the northern end of Loch Lomond.
Flooding on the same line between Cardross and Craigendoran, near Helensburgh, also halted trains last night to and from Edinburgh.
Tomorrow up to 30-40mm of rain is forecast in some places away from the west coast, the Met Office said.
A yellow - be aware - weather warning will be in force until 10pm, starting at midnight in the north east and eastern Highlands, and 11am over the rest of Scotland.
A Met Office spokeswoman said for the north: “Heavy showers and thunderstorms will continue to affect some areas into Wednesday morning before developing more widely through the day.
“Rainfall accumulations of 15-20mm in an hour are possible locally, with isolated totals of 40mm in a few hours.”
She said for the rest of the country: “Heavy, occasionally thundery showers are expected to develop by late Wednesday morning and through the afternoon, then slowly die out during the evening.
“Though many areas will miss the worst of these thundery showers, a few spots could see 15-20mm within an hour and 30mm within three hours, as well as lightning and some hail.”
A total of 17 flood alerts - an early indication of potential flooding - covering the whole of Scotland apart from Orkney and Shetland have been issued by the Scottish Environment Protection Agency.
Network Rail said the West Highland line would be closed for at least a week by “two significant washaways” south of Crianlarich station and severe damage to ballast near Tyndrum Lower station on the Oban branch on Sunday.
The operator's spokesman said: “This will be a very complex fix as we will need to reconstruct the slope beneath the line at several points at the worst affected location near Crianlarich.
“We have specialist engineers assessing the damage to the slope and planning the repairs needed to reopen the line.
“This is a complex engineering challenge that will require thousands of tons of lost material to be replaced beneath the railway.
“We are working hard to restore a full service as soon as possible for customers.”
A ScotRail spokesperson said: “The line will remain closed for the next seven days while engineers carry out vital repair works.
“A temporary timetable will be in place to keep our customers moving where possible.
“We’re working hard to source alternative transport and we’re sorry for the inconvenience this will cause some of our customers.”
However, the spokesperson said getting replacement buses was proving challenging because it was the peak tourist season.
“We will keep customers updated over the coming days.”
Flooding on the A82 between Arrochar and Crianlarich added to travel problems yesterday, delaying passengers using the replacement buses further.