DENSE fog is expected to reduce visibility to just 50 metres in parts of Surrey and Hampshire overnight.

The Met Office has issued a severe weather warning, with fog patches expected to form on Friday night and become dense by Saturday morning.

Not everywhere will see fog, but where it does form visibility will fall below 100 metres in places, and perhaps below 50 metres in a few spots.

Forecasters have warned the public to be aware of potential for some travel disruption and difficult driving conditions.