The Met Office has issued a yellow weather warning for thunderstorms in Watford and the southeast for the rest of today (August 17).
An amber weather warning, which covers large parts of London and warns that "flooding of businesses and homes is likely", also only narrowly falls short of Watford at present.
A Met Office spokesperson said: "Heavy showers and thunderstorms are expected to break out today leading to some flooding and disruption.
"Some places will miss these, but where they do occur, 30 to 50 mm of rain could fall in less than an hour and a few places may see in excess of 100 mm in a few hours where storms are slow moving.
"Lightning and hail will be additional hazards. Showers and storms will slowly die out this evening."
What do weather warnings mean?
Met Office issues yellow weather warning for thunderstorms in Watford
In terms of what to expect, the Met Office has said:
- Flooding of homes and businesses could happen quickly, with damage to some buildings from floodwater, lightning strikes, hail or strong winds
- Fast flowing or deep floodwater is possible, causing a danger to life
- Where flooding or lightning strikes occur, there is a chance of delays and some cancellations to train and bus services
- Spray and sudden flooding could lead to difficult driving conditions and some road closures
- Power cuts might occur and other services to some homes and businesses could be lost
You can view the forecast via the Met Office website.
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