Heavy rain and thunderstorms could batter Britan as the after-effects of Hurricane Humberto are felt.
The Met Office has issued a yellow weather warning for Tuesday in London and the South East to South West.
Travellers, particularly on Tuesday morning, should brace themselves for disruption as experts expect the storms to last until 3pm bringing potential flooding.
Met Office meteorologist Luke Miall said: ‘We could see 20mm to 40mm of rain within nine hours and possibly the worst case scenario is of 70mm in some spots’ with the possibility of the ‘odd rumble of thunder’ in some areas.
The weather warning says: ‘Spells of rain and heavy showers are expected to affect southern parts of England and Wales during Tuesday.
‘The heaviest rainfall is likely to be during the morning.
‘Much of the rain will fall in a relatively short space of time, typically less than six hours.’
It is still uncertain where the very heaviest rain will fall.
Mr Miall said there will still be a wet start to Monday too but pockets of sunshine could push temperatures to a slightly warmer-than-average low 20s.
The seasonal norm is mid-to-high teens.