No lightning is currently forecast in Southampton.
The warning says: "There is a small chance that homes and businesses could be flooded quickly, with damage to some buildings from floodwater, lightning strikes, hail or strong winds.
"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.
"There is a slight chance that power cuts could occur and other services to some homes and businesses could be lost."
Source : https://www.dailyecho.co.uk/news/19484395.southampton-weather-forecast-met-office-lightning-warning/197