Bet you didn't think the current cold snap is likely to have its origins in the tropical Pacific.

Our science correspondent Jonathan Amos looks at the story behind the weather.

It's not all doom and gloom, of course.

With many children having the day off school, today has been the perfect opportunity to get the sleds out to fly down some hills.

Our reporter Ben Price captured this footage from outside Caerphilly Castle.

Shopping isn't usually a weather dependent activity, but those in Cardiff may be disappointed as all stores at St David's 2 have closed for the day to let staff get home.

Mixed fortunes for people in mid Wales according to BBC Wales’ Craig Duggan. No snow in Aberystwyth, a little in Machynlleth……but snow ploughs are out in Caersws!

Have you been put off going shopping because of the weather?

Well, you wouldn't be the only one. Diane Wehrle, Insights Director of business data analysts Springboard said the number of people shopping across the UK has fallen by 11.8% since the "Beast from the East" hit.

She also said it could "worsen substantially" as Storm Emma takes hold.

While others are worrying about the snow, James Maloney's dog Jet is relaxing by the fire in Caerleon, Newport.

Image source, James Maloney

Before making use of council salt bins, take a look at these top tips from Monmouthshire

Empty shelves at Sainsbury's in Bridgend

The A4060 at Merthyr Tydfil is closed in both directions due to a jackknifed lorry.

The trailer has detached and is spilling diesel over the carriageway.

The scene on the A470, at Pontypridd, is much calmer, with very little traffic on the roads.

The red "extreme weather" warning is now in place until 02:00 GMT on Friday.

Here's our weather forecaster Behnaz Akhgar with the latest updates.

Cwm Taf University Health Board has confirmed all outpatient appointments and routine operations will be cancelled on Friday morning.

Aneurin Bevan health board has also postponed appointments for the next two days.

We brought you news this morning of Cardiff Blues' Pro14 match at home to Benetton Treviso being called off on Friday and now more fixtures have bitten the dust.

Ospreys' match away to Zebre has been postponed, as have Newport County's League Two match with Accrington Stanley and Wrexham's trip to Ebbsfleet.

It's better news for the Dragons, who are playing the Southern Kings in Port Elizabeth in South Africa, where it's expected to be 23C.

Alright for some.

Some who have seen it all before may hate the snow....others are enjoying it for the first time

One of the biggest victims of the snow seems to be the annual celebration of Wales’ patron saint – not just in Wales but in London too.

A traditional St David’s Day debate in the House of Commons was cancelled to allow MPs to travel back to their constituencies before conditions worsened.

Some bus services are grinding to a halt – with Stagecoach suspending services in Torfaen, Blaenau Gwent, Caerphilly and Newport from 15:30 GMT.

Those in Rhonda Cynon Taff, Aberdare, Merthyr Tydfil and Brecon will stop from 18:00.

Anyone trying to get around on the rails this evening may have trouble.

Services are shutting down for the day.

It might be time to look for a hotel for the night if you're at risk of being stranded.

Despite the vast majority of schools across south east Wales closing for the day, some kids and teachers still had to venture out to the classroom.

Birchgrove Primary School in Cardiff stayed open, meaning children could take part in St David's Day celebrations.

However, the school will be closed tomorrow.

The Met Office red "extreme weather" warning for wind and snow is now in place and will last until 02:00 GMT on Friday.

Heavy snow and blizzard conditions are expected, with freezing rain also possible as we move into Thursday evening.

Damage to buildings and infrastructure is possible and there is a risk to li

Seagulls try a spot of ice skating in Barry, as BBC Wales' Kate Rimmington waits for the red alert to kick in

Travelling is not advised in this weather, but if you are going anywhere, South Wales Fire and Rescue has tweeted this guide to taking care on the roads.