THE BLOG

Come Back Jet Stream - All Is Forgiven!

28/03/2013 17:58 GMT | Updated 28/05/2013 10:12 BST

I've just arrived home from the Atacama Desert in Chile - filming a documentary for kids on the driest place on the planet. The location was perfect for an outdoor shoot; dry, and despite the risk of fog most days turned out sunny. My 24 hour journey home turned into 34 hours as we were stranded at Charles de Gaulle airport because of the snow across the UK and France.

On my return I was more than a little surprised to hear about how extensive the snow had been. In my 20 years forecasting, most winters I've gone searching the charts for it. This year the snow had obviously come knocking.

Looking more closely I could see what had happened...

The jet stream had taken a vacation, migrated south for the winter leaving the UK at the mercy of a relentless icy blast.

It's times like this when I realise the immense impact this ribbon of strong upper winds has on our weather - although through the past few years we have cursed it. During the summer months we prefer the jet stream to head north, but recent summer seasons have seen it deliver untimely wind and rain to us, whilst the fine weather has stayed away. I was in Iceland last month, and more than one local commented on just how fantastic the summer of 2012 had been. Mmm.

The jet stream, that spawns depressions out in the Atlantic, keeps our countryside green, reservoirs topped up and more relevant to us right now, moderates the air temperature over the UK.

So when, during the winter, it goes AWOL, the mild westerly winds are replaced by bitter conditions that blow in from the north and east, and everything freezes. This time its remained south for far too long, which means March is likely to be the coldest in the UK since 1962, and maximum temperatures, the lowest since records began back in 1910. But things are even more serious, this month we have been talking about snow in terms of feet rather than inches - a rarity, and with some devastating consequences. England has only received an average amount of precipitation this month, the rest of the UK even lower, this highlights how disruptive a dumping of snow can be - one inch of rain is equivalent to a whopping 10 inches of snow, we've seen the results on news footage around the country.

The Easter weekend weather is looking quiet - and fairly pleasant if you can escape the biting cold. Good Friday will still be prone to snow showers especially over the eastern half of the UK, but these will be a scattered affair. The rest of the weekend remains mostly dry, always with the chance of a few snow flurries but sunshine for some and hard frosts for most by night.

There is a weather front skirting the far southwest of England, current indications are that it won't have any impact over most of the UK - but it's worth a watch. The other key feature will be a strengthening wind in the south towards the end of the weekend, this will make it feel even colder. There is little change in our fortunes next week, as this cold, dense air remains over us, blocking any mild winds attempting to rescue us from the grip of this extreme winter.

Some parts of the Atacama haven't seen rain in recorded history - and it was clear to me whilst out there, a lot of the same weather causes big problems for everyone. Here at home, our weather normally changes like the wind (pardon the pun) and although this can be frustrating it does mean spells like this dreadful cold snap won't last forever. So come back jet stream, all is forgiven, but please don't hang around all year, as it's our turn for a warm and sunny summer.

Clare Nasir has been on location filming the second series CBBC's Fierce Earth.

She covers 5News weather this week and next