Thunderstorms are expected to batter parts of Glasgow and south-west Scotland as the Met Office issued a yellow warning.
A risk of flooding has been highlighted, with the national weather service putting a caution in place from 1.30pm on Tuesday until 6am on Wednesday.
Disruption is expected and where water builds up or lightning strikes occur, commuters have been warned of possible delays and cancellations to train and bus services.
Spray and sudden flooding could lead to difficult driving conditions and some road closures in parts of the country.
As well as Glasgow, the yellow warning extends to cover western areas such as Greenock and Helensburgh and coastal towns such as Troon and Ayr.
It also stretches to cover south-west Scotland.
STV meteorologist Sean Batty said: “We’ve got low pressure around just now, which means the air is rising, but add in the fact we’ve got some warm and humid air, it’s the perfect recipe for some thunderstorms.
“As you can see from the warnings the main risk is west central and south-west Scotland. Up to 35mm or rain could fall in an hour in some of these storms, which could lead to very localised flood issues, especially if the storms occur over towns or cities where drains may struggle to cope with that volume of water in such a short space of time.
“What I should point out, is thunderstorms come from clouds known as cumulonimbus clouds which can pass over an areas just several miles wide. This means that some areas could completely escape them and stay dry.
“The storms should ease later tonight, before rain comes in to affect central and southern Scotland later.”
In southern parts of the country, areas such as Dumfries and Galloway are likely to be affected, where the Scottish Environment Protection Agency (SEPA) has issued a flood alert.
An update from SEPA said: “Heavy and thundery showers are likely to develop in the area through Tuesday afternoon and evening, although not all places will see them. This may lead to flooding from surface water.
“The greatest risk is if these occur over built-up areas and the transport network. Possible impacts could include: flooding of properties, parts of communities and roads, and disruption to travel and infrastructure.
“Localised flooding of land and roads is also possible from river flooding should heavy showers occur over small or fast responding watercourses.”