Extreme global weather

The UK may be experiencing what looks likely to be a milder than average winter but other parts of the globe are struggling against some extreme weather conditions.

Middle East

Heavy snow is expected to affect large parts of Turkey, Georgia, Armenia and SW Russia early this week. As the cold conditions spread east later in the week, strong to gale force winds and heavy snow are expected across more eastern parts of the Mediterranean.

This will lead to the Middle East seeing temperatures 10 or 15C below normal for the time of year. For example, overnight temperatures could fall to -10C in Syria by mid week, with daytime temperatures struggling to rise above freezing.

This is likely to have a significant impact on refugees and the humanitarian aid agencies in Turkey, Jordan, Lebanon, Syria and Iraq, with problems enhanced by the threat of frozen water supplies. Although overnight temperatures of -5 to -10C are expected, these values may well fall much lower if there is snow cover.

North America and Canada

Large areas of the USA and Canada are experiencing very cold conditions, with the threat of heavy snowfall across some parts over the coming days.

The eastward movement of a cold front over the weekend has dragged very cold air down from the arctic. Temperatures across parts of Canada have fallen to -30C, and widely across North America, daytime temperatures have ranged between 0 and -6C, with the bitterly cold conditions enhanced by strong winds.

As well as the low temperatures, some parts have seen heavy snowfall, such as the Pacific Northwest and areas to the east of the Great Lakes.

Further heavy snowfall is expected this week, particularly down-wind of the Great Lakes due to “lake effect” snow. This is caused when cold flows across relatively warm bodies of water such as the Great Lakes. The air rises in strong convective currents which creates clouds and heavy precipitation. In these very cold conditions, the moisture in the clouds will fall as snow.

Lake Superior (top left) and Michigan (centre) can be seen generating 'lake effect' snow. Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

Lake Superior (top left) and Michigan (centre) can be seen generating ‘lake effect’ snow. Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

The significance of this is highlighted by snowfall projections over the coming days. Lake Ontario, the easternmost of the Great Lakes with a surface area of 18,960 km2, is expected to bring narrow bands of heavy snow to areas east of the lake. These narrow bands could generate 2-3 feet of fresh snow over the next 24-36 hours causing significant disruption.

Whilst the freezing temperatures are expected to last throughout the week, temperatures may recover slightly through the weekend.

Will the US weather affect the UK?

The cold conditions will have the effect of strengthening the jet stream, which will move close to the UK over the coming days. This will bring unsettled conditions through this week, with spells of wet and windy weather, particularly across northwestern parts of the country. However, it will be mild, particularly towards the end of the working week when daytime temperatures could reach around 14C.

There is the potential for the remnants of this cold air to move eastwards across the Atlantic to affect the UK over the weekend. However, the airmass will become heavily modified by the Gulf Stream, and there is little risk of the extreme temperatures over North America affecting the UK.

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5 Responses to Extreme global weather

  1. xmetman says:

    I’ve mapped the large 24 hour temperature falls across the east of America and compared them to the large rise in temperature that we saw over the New Year in the UK:

  2. xmetman says:

    Large area of snow across central Turkey overnight. See 0600 UTC reported snow depths here…

  3. nuwurld says:

    Thanks Met Office. Interesting post covering other countries experiencing their Northern Hemisphere winter, which is for many places not like ours here in the UK.

    As someone who has often criticised the determination of ’cause’ from ‘effect’, I was particularly pleased with this line you used,

    “The cold conditions will have the effect of strengthening the jet stream, which will move close to the UK over the coming days.”

    The jet stream being a geostrophic wind ‘produced’ by, and relative to, the thermal gradient at the polar (cell) front and Ferrel (cell) boundary.
    The position now of the polar front way down into lower latitudes across the ‘States will produce intense gradients with air over the west Atlantic waters producing a strong upper jet and potential ‘bomb’ cyclogenesis whilst conditions persist.

    Northern snow and ice conditions around the Hemisphere can be checked here and compared with European conditions;

    Regards, Geoff

  4. jbenton2013 says:

    If something has happened many times before, as all these weather patterns described in this article indeed have (snow in winter in Canada, USA and Russia – shock horror), it is debateable whether they can be accurately described as extreme.

    Why not leave the hyperbolic descriptions to tabloid journals, who rely on terms like “extreme” to attract sales, and instead rely on more accurate scientific headines.

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