The Met Office has issued flood warnings for the UK, with two inches of rain set to hit the country today.
Forecasters have put out yellow rain warnings for south Wales and south and south-west England this morning.
Another Met Office rain alert will come into force in Scotland this afternoon, with meteorologists warning that flooding is likely.
Bus and train services are set to be disrupted in the affected areas.
The Met Office's rain alert for England and Wales started at midnight and will last until 1pm today.
The warning says: "A band of rain will move east across southern parts of England and Wales during Tuesday morning.
"Some of the rain will be heavy, with 15-30 mm of rain falling widely and as much as 40-50 mm over parts of Dartmoor and south facing high ground of southern Wales and the Marches and parts of southern England."
The Met Office's weather warning for east Scotland starts at noon and ends at 9pm.
The alert predicts potentially more than two inches of rain in parts of Scotland.
It says: "A band of rain will move east across Scotland Tuesday becoming persistent across the southern Highlands during the afternoon.
"20 to 40 mm of rain is likely to fall widely here with as much as 50 to 60mm over higher ground of Aberdeenshire, Angus and Perth and Kinross."
Commenting on the stormy outlook, Met Office Chief Meteorologist Steven Ramsdale previously said: “Rain will affect much of the UK during the early part of this week, with a weather front on Tuesday bringing heavy rain and strong winds at times.
“Rain on Tuesday is likely to bring some impacts to travel and some possible flooding in places.
"Parts of southern Wales, southern England and eastern Scotland are likely to see the heaviest and most persistent rain, with over 30mm of rain in some places and some exposed parts of eastern Scotland potentially seeing 50mm.
"It will be a wet day for many however with 10-20mm of rain falling across much of England, Wales and Scotland.”
Gusts of more than 60mph are expected in some coastal and northern areas going into Thursday.
