Thundersnow: What is the rare weather phenomenon that woke up Hampshire with a 'bang'?

  • Weather

Video report on travel disruption by ITV News Correspondent Dan Rivers

Residents across southern England have reported being woken up by a loud "bang" as thundersnow hit the region.

Social media lit up early on Sunday morning as users posted pictures of the snow.

Hampshire residents reported "a belter of a thunderclap followed by snow flurries" just after 6.30am, while another said the event had "tripped" his power supply.

What is thundersnow?

What sounded like an explosion, this rare weather phenomenon is actually caused when the air close to the ground is warm enough to cause a thunderstorm, while the cold air above produces snow.The snow enhances the lightning, it appears brighter than normal - that's because it reflects and bounces off the snowflakes.

In a typical thunderstorm, the thunder can be heard many miles away, but in a thundersnow event, the sound is only heard if you are within two to three miles of the lightning.

So this explains the explosive sound and the rude awakening for some.

The Met Office said a band of snow will move into south-west England and Wales in the early hours of Sunday morning, spreading to the East Midlands and south-east England later in the day.

Drone footage from Sutton Coldfield in the West Midlands showed streets blanketed in snow.

Five weather warnings for snow and ice are in place across north-west England, Northern Ireland, south-west England and South Wales, the Midlands, and south-east England.

Martin Bowles, meteorologist at the Met Office, said: “The biggest hazard over the next couple of days is going to be ice because we’re getting these snow showers which will all freeze overnight.

“Obviously roads tend to be quite well gritted, especially main roads, but I would warn people to be careful on pavements, minor roads that don’t get gritted or city roads.”

Mr Bowles said the cold spell would continue until about Wednesday before being replaced with milder temperatures in the final days of the month.

“That’s not to say that that’s the end of all cold weather for winter, it isn’t, we’ve just got a mild spell coming up,” he said.

Despite people being urged to heed flood warnings into the weekend, Mr Bowles said they were “gradually reducing” and that more heavy rain was not expected until Wednesday night or Thursday.

“We’re hopeful that the river levels will fall quite significantly before that so we’re not expecting any significant flooding problems over the next few days, apart from in areas where the warnings are already in place,” he said.

The Environment Agency previously warned of “exceptionally high river levels” following days of heavy rainfall in the wake of Storm Christoph, with hundreds of properties across the country flooded.