JACK B/WEATHER WATCHERS
Thunderstorms have caused flooding in London and south-east England, with more than 300 emergency calls made to the fire service overnight.
London Fire Brigade took a day's worth of calls in 90 minutes, with its crews attending flooded premises and roads as well as properties hit by lightning.
A Met Office yellow "be prepared" warning has been issued, after reports of 40mm (1.5ins) of rain in some areas.
RICH WALTERS
Rivers in Bromley and Sidcup in south-east London, and Basildon, Essex, are affected, and there are 24 flood alerts in place.
Meanwhile, Gatwick Express, Abellio Greater Anglia, South West Trains and Southern have warned of major delays on some rail routes.
In London, flooding has led to the suspension of services on the London Underground and on the overground services.
A Network Rail spokesman said: "It's a very fast moving picture this morning, with flash floods still arising and others falling in a variety of different routes into London.
"In addition, we are dealing with the aftermath of lightning strikes at Surbiton, which is on the main line into Waterloo, and at Blackheath.
"Our advice to passengers in the South East this morning is to please check before you travel, either with your operator's website or on National Rail Enquiries."
A fire service spokesman said: "Crews are being mobilised to incidents as quickly as possible but the brigade is appealing to people to only call 999 in an emergency - where there is a risk to life or property."
On Twitter, Transport for London posted incidents of localised flooding on roads, including the Blackwall Tunnel in the east of London, which was temporarily closed.
BBC Weather said there had been more than 1,000 lightning strikes across the UK overnight, although the thunderstorms are easing.
The Met Office said the rain was brought on by increasingly warm and humid air arriving from France.
Forecasters are warning of the potential of a "second wave" of downpours later on Thursday.
