The Met Office has warned commuters across England and Wales to expect disruption due to a “pretty unsettled day” of weather involving heavy rainfall.
A yellow weather warning is in place for most of England and part of Wales on Tuesday morning as heavy rain and potential flooding is expected.
The downpour is being brought by a burst of low pressure travelling across the UK, along with warm and humid air linked to the remnants of Hurricane Humberto which hit the Bermuda coastline last week.
England and Wales can expect 30mm to 50mm of rain in a short time on Tuesday, with up to 70mm in isolated spots.
Forecaster Mark Wilson warned of “thunder, lightning and gusty winds” through the affected areas.
“It’s very likely there will be issues with surface water causing flooding,” he said.
A “brief respite” in some parts is expected in the early afternoon, Mr Wilson said, adding that “more rain is predicted for the evening.”
“It’s looking like pretty wet weather all round through the southern parts of the UK,” he said.
Mr Wilson urged people to stay updated with the Met Office forecast throughout the day.
Commuters on Tuesday are set to face the worst of the disruption, with buses and trains likely to be affected by the heavy rain.
Mr Wilson continued: “About rush hour tomorrow morning places like London and the South East will see the heaviest rain, but by the evening rush hour it will likely be seen in the North East of England, as the front is moving northward.
“There could be delays and cancellations and a lot of spray on the roads and that may lead to road closures.”
He added that localised flooding could cause issues with the transport network.
Tuesday’s weather warning is set to last until 11pm and although the heavy rain is expected to clear by Wednesday, a low-pressure front is expected to remain for the rest of the week.
This will bring bright and breezy weather to the UK along with some showers or prolonged spells of rain.
Temperatures could rise to the low 20s, which is slightly warmer than average for early autumn.
The norm for this time of year is in the mid-to-high teens.
Yellow weather warnings were also in place in some places during the weekend, with scattered thundery showers on Sunday afternoon.