3 Feb 2012

Here comes the snow

In my last blog I mentioned that the weather was set to reach another interesting fork in the road this weekend as mild air and cold air battle it out across the UK.

As a result of this battle, some places will see notable snowfall – especially across central and eastern areas, where the Met Office has issued an amber warning for snow.

Whilst the general theme of rain moving in from the west and turning to snow as it meets colder air is certain, the difficulty lies in the detail of exactly where, when and how much snow there will be.

Snow is always very difficult to forecast in the UK because the temperature is often around 0C when it falls and a slight rise in temperature by just a single degree can mean that rain falls rather than snow.

The main uncertainty for this weekend is how far eastwards a weather front moves, because as well as giving snow, behind it, milder air will follow turning any snow back to rain.

At the moment it looks as though this weather front will grind to a halt across the middle of the UK.

This means that western areas – such as Northern Ireland, Wales, south west England, western Scotland and low lying parts of north west England – will see milder air move in during Saturday, turning any snow back to rain.

Central and eastern parts of the UK are likely to remain in the colder air, so here there is a greater chance of the snow persisting later on Saturday and into Sunday.

5-10cm is possible widely, with more for northern England – especially across the hills and mountains. Ice will be an additional concern for many areas, with untreated roads at greatest risk.

Another possibility is that there could be some freezing rain. Temperatures have fallen well below freezing during the past few nights, so even if milder air and rain moves in, the ground could still be frozen.

Read more: Snow forecast as UK temperatures plummet to -11C

This would result in rain freezing upon impact with the ground and giving dangerously icy conditions – most probable for western areas on Saturday.

There’s been a lot of discussion in the newspapers today about the forthcoming snow and how severe it’s going to be.

The important thing to bear in mind is that whilst some disruption is likely, it’s not going to be on the scale of what we’ve had during the past two winters, when much of the UK was covered in 10-30cm of snow for a few weeks.

However, it’s still worth taking extra care if you’re travelling this weekend and staying in touch with the forecast to get the latest information.

I’ll be posting updates on Twitter from @liamdutton and discussing the latest developments as they happen. Your weather reports and pictures are also welcome and much appreciated.

Tweets by @liamdutton