Met Office warning of heavy snow

Children on Anglesey making the most of Tuesday's snowfall

The first heavy snowfalls of the winter in south and mid Wales are predicted overnight on Wednesday and early on Thursday morning.

Forecasters have issued an early severe weather warning saying some areas could have up to 15cm (6in) of snow.

It is predicted it could bring travel disruption and make Thursday's early morning rush hour difficult.

Lesser snowfalls - of up to 10cm (4in) - are expected to hit the Midlands and southern English counties.

BBC Wales weatherman Derek Brockway explained that the band of heavy snow would be caused by cold air from the north mixing with mild air from the Atlantic.

It's this kind of weather pattern that can bring Wales its worst blizzards Weatherman Derek Brockway

"Most places will see between 2-5cms of snow, but parts of south mid and east Wales - the valleys, Monmouthshire and Powys - could see as much as 10 or 15cm, that's 4-6in.

"And drifting is likely too, especially on high ground.

"The air over us at the moment is from the Arctic. This trough of low pressure will move into northern France but another low pressure will develop in the Atlantic.

"This will move towards us, bringing stronger winds and as it bumps up against the cold air, snow is likely.

"It's this kind of weather pattern that can bring Wales its worst blizzards. So it would be worth keeping an eye on the forecast.

There has already been some snow on higher ground in Anglesey and north Wales on Tuesday.