Commuters face travel chaos as half a month of rain falls in hours
Commuters faced a day of travel misery as half a month of rain fell in a few hours causing widespread transport delays across southern England.
Railways and roads were closed, buildings flooded and a train derailed near Watford Junction after hitting a landslip caused by the deluge.
Holidaymakers faced missing their flights as rail services to Stansted Airport were disrupted by branches coming into contact with overhead line equipment.
Lightning strikes left thousands without electricity, caused fires and temporarily closed railway lines.
Up to 2ft of flood water at Didcot Parkway and Newbury stations in Oxfordshire caused travel chaos. The deluge flooded the underpass at Didcot, meaning only one platform could be used.
Lines at Newbury were submerged by the water preventing services from stopping until one platform operated a reduced service in the afternoon.
The bad weather could continue into Saturday, compounding affected areas further, the environment agency warned.
Water submerged stretches of motorway including on the M4 and M25, where two lorries crashed at around 5.20am.
It was hoped the anticlockwise carriageway of the M25 and the M4 at junction eight would be fully open "before tonight's peak period, unless weather conditions change again," said a Highways England spokeswoman.
Around 1,200 homes across Basingstoke, Newbury, Reading and Bournemouth were left without power as a result of lightning, but the "vast majority" were expected to be connected again by Friday evening, energy provider SSE said.
London and the South East were the worst-hit areas, with a yellow rain warning for the east of England in place until 7pm.
Two people were injured when a train "gave a glancing blow" to another coming in the opposite direction after derailing near Watford Junction during morning rush hour.
The incident caused major delays to services and London Midland warned passengers to avoid travelling to or from London Euston, with normal services not expected again until Monday.
Network Rail said they were still working to remove the two trains from Hunton Bridge Tunnel and carrying out repairs and safety checks.
A spokesman said: "We hope to have normal service through the area in time for the Monday morning peak."
Maintenance labourers worked through the day pumping water and repairing equipment to ensure schedules got back on track.
Great Western Railway spokesman Dan Panes said: "Staff are out in force to reduce the water with pumps and outside assistance.
"However, we need to make sure it is safe to run trains and for passengers to access those stations before we can fully open those services."
Lightning struck a row of six garages in Knaphill at around 9.30am starting a fire on Beechwood Road, Surrey Fire and Rescue Service said.
Environment Agency flood risk manager Jonathan Day said teams were out clearing river and stream grates of debris and would issue flood warnings and alerts where necessary.
"Further rainfall is expected on Friday afternoon. This may cause some localised disruption to transport and impacts to property from surface water flooding," he said.
"Showers could also develop on Saturday afternoon in the far south east of England. People should remain vigilant and check travel arrangements as this could fall across areas already affected by Friday morning's downpours."
Mr Day urged people "not to drive through flood water", saying it is "often deeper than it looks and just 30cm of flowing water is enough to float your car".
Schools also closed because of flooding included Gade Valley Junior Mixed Infant and Nursery School in Hemel Hempstead and All Saints Church of England Primary School in Didcot, Oxfordshire.
Met Office meteorologist Martin Combe said 32.8mm of rain fell in three hours in Farnborough, Hampshire - nearly half the 70mm average for the month of September.