15 Jan 2015

A week of cold to follow the storm

Whilst the latest winter storm may look beautiful from the silence of space, down on the ground it has been a different story.

Howling winds have lashed the UK and Ireland through the night, with gusts reaching 96mph in places, leaving a trail of disruption.

It hasn’t just been the vicious winds, heavy rain has swept across the country too, falling on saturated ground and causing some localised flooding.

uk_storm15thJan_EUMETSAT_wp

This is the third winter storm to hit in a week (see Nasa satellite movie below), taking the UK on a rollercoaster ride of weather, flipping from snow and ice to rain and gales, then back again.

Powerful jet stream

The reason for a week of stormy weather has been an extremely fast-moving jet stream speeding across the Atlantic Ocean, reaching speeds of up to 280mph 30,000ft up in the atmosphere.

Such a powerful jet stream is being driven by a much stronger than normal temperature contrast at the moment, between very cold arctic air and warm sub-tropical air off the east coast of the US.

This fast-moving ribbon of air high up in the atmosphere sucks air upwards from the surface faster than it can be replaced, causing pressure to fall rapidly and storms to form.

The jet stream is not only responsible for spawning these storms, it also acts as an atmospheric superhighway, catapulting them our way.

However, the jet stream is going to slow down and meander south of the UK into next week, meaning that this will be the last of the vicious storms for a while.

A week of cold weather

Once the current storm moves away through Thursday night, it will open the gates to cold arctic air from the north into the weekend.

As a result, showers will readily turn to sleet, hail and snow from today onwards – especially over the hills and postbox_snow_g_wpmountains, but down to lower levels at times too.

The latest information from a number of weather computer models suggests that the cold weather will persist for around a week, with temperatures below average for the time of year.

In fact, it could end up being the longest period of cold weather we have seen in recent winters, which have been characterised by wind, rain and mildness.

Temperatures next week will struggle to get much above freezing by day in many areas, at 1-5C, falling well below freezing at night.

With areas of low pressure drifting in from the west at times, there will also be a risk of snow, but the detail so far ahead remains uncertain at this stage.

Don’t forget, you can get the latest forecast on the Channel 4 Weather website. I’ll also be posting regular updates on Twitter – @liamdutton

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