Published on 14 Feb 2014

Weakening jet stream means a less stormy outlook

As I write this, another storm is slamming into the country, bringing more heavy rain and severe gales to our battered shores.

Since late December, a powerful jet stream – often travelling at around 200mph five miles above the Atlantic – has been spawning vigorous areas of low pressure and catapulting them towards us.

Being an island at the eastern edge of the Atlantic ocean, we’re used to getting storms during autumn and winter, but not relentlessly for such long periods of time.

sunset_cornwall_g_wp

The Somerset Levels are under water for the second month in a row, and the flood risk remains medium to high across a large swathe of the Midlands and southern England in the coming days.

However, finally, there looks to be some light at the end of the tunnel, in what has been an exceptional spell of extreme weather.

Weakening jet stream

lighthouse_wave_g_wpThroughout this winter, the jet stream has been 30 per cent stronger than average, according to the Met Office.

The stronger jet stream has been driven by a bigger than normal temperature contrast off the east coast of Canada. This has super-charged it and turned it into a storm-making machine.

Next week, the jet stream is set to weaken notably to a speed of around 130mph – in stark contrast to the 200mph or so we’ve seen this winter.

Less stormy next week

A weakening jet stream will lead to the frequency and intensity of low pressure systems decreasing next week, giving weather that is nowhere near as severe as what we’ve experienced in recent weeks.

Whilst it won’t be completely dry, rainfall won’t tend to be as intense, with lesser amounts falling when it does rain. This will give the chance for water levels in rivers and on the Somerset Levels to go down.

The winds will also come down a notch, with the severe gales much less likely.

rainbow_uk_g_wpLow pressure will also tend to take a more northerly track across Scotland and Northern Ireland, which will allow ridges of high pressure to nudge into England and Wales from time to time.

However, before all this happens, severe gales and heavy rain will continue to batter the country for the rest of Friday into Saturday morning.

Further flooding problems are likely and the severe gales in southern areas could bring down trees and cause travel disruption.

You can get the latest forecast for your location on the Channel 4 Weather website. I’ll also be posting updates on Twitter – @liamdutton

Tweets by @liamdutton

5 reader comments

  1. K B STALLARD says:

    Dear Sir, You may think i am wrong, but i know that seeding by the U S A,and Can,have done this to the weather,K B S.

  2. faddy says:

    Confusingly, this seems to blame a slower jet stream for this Winter’s weather:

    http://www.bbc.co.uk/news/science-environment-26023166

  3. Finn McCann says:

    If jet-stream is a natural occurring phenomenon why is it currently creating such havoc & how can human behaviour adjust it?

  4. Ashley Haworth-roberts says:

    http://www.bbc.co.uk/news/science-environment-26023166
    The above blog post is about the recent very fast jet stream in the vicinity of the UK that has lasted through much of this winter. But elsewhere the jet stream might have been rather slower with more of the meanders which sometimes persist largely unchanged for weeks (perhaps resulting from arctic warming – though not in the Canadian part of the Arctic hence the big temperature differential over America caused by both very cold air over Canada and some very warm seas in more southerly parts of the north Atlantic).

  5. john harper says:

    High Frequency Active Auroral Research Program

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