Snow in UK; Scandinavia freezes, but mild winter is forecast

Earliest widespread snow in Britain for 17 years apparently. Third day in a row of snow here and after a dry day a sudden heavy shower as I was driving home from work turned the city roads white. Despite care, appropriate speed and engine braking, I skidded to a halt approaching traffic lights down a hill. That was fun (thankfully I can say that).

The cold is set to last for at least another week in the UK, and it is strange to have it cold so early.  Although the Met Office is no longer making seasonal forecasts since the much ridiculed “BBQ Summer”, this seasonal forecast by its Norwegian counterpart, the Meteorologisk Institut,  caught my eye.

Forecast from met.no: predicted temperature deviations from normal in the period December 2010 to February 2011

The seasonal outlook for Norway for the period December 2010 – February 2011 is temperature above the normal for the whole country. The greatest deviation from the normal is 2.5 °C above and this is located to the inner part of Southern Norway. For most of the coastal areas the seasonal outlook is 1.5-2 °C above the normal. For the rest of the country it is ca. 2 °C above the normal. The normal period 1961-1990 is used here. It is important to keep in mind that the values presented in the map are three monthly averages. Information about the different months is not given. The seasonal outlook is only made for the temperature at present and does not give any information about expected precipitation.

This has been higher profile in the news in Norway than normal since the country, like the rest of Scandinavia, is in the grip of very cold temperatures.  Earlier in the week an Aftenposten article set this forecast against the potential for record breaking cold this week.  [Update: even lower temperatures forecast for next week]

Record Cold? According to a State Meteorologist at the Norwegian Meteorological Institute the cold wind from Siberia sets old (November) records at risk:

  • Blindern in Oslo, in 1965 measured 16 degrees (C) below freezing. For Thursday and Friday minus 13-14 degrees is predicted.
  • In Bergen, the record from 1985 is 8.9 degrees below freezing in the centre. Towards the end of the week Bergen expects 7-8 below.
  • Tromsø measured -12.5 degrees in 1955. Here, minus 10 degrees is forecast.

However, experts, scientists and meteorologists are not unanimous in prediction of seasonal temperatures.  In contrast to the Norwegian forecast, senior scientist and climatologist John Cappelen at the Danish Meteorological Institute (DMI) suggests a cold winter ahead.  He sees the characters in the higher layers of air that remind him of conditions that last year provided stable and cold weather.

“We are now in a phase where NAO is very strong and negative, just like last winter.  Continuing the trend, so it may mean that there is a chance for another cold winter in the north-western Europe” says Cappelen.

But he is not so sure of a cold winter as it appears in the media – “The conditions can rapidly change.” A negative NAO means that the wind blows steady from the east and the winter weather is dry and cold, has remained stable for a year. It has the not been this way for 40 years.  “It was this tendency that gave the cold winter last year” says Cappelen. The open question is how long and how strongly the phenomenon continues.

His employer, DMI, has a forecast for the first three months indicating that the temperature is 0.4 degrees warmer than average for the period 1961-90. If this bears out, the winter will be milder than last year, but colder than in recent years.  The Aftenposten article also mentions a report on yr.no (Met.no equivalent of BBC weather news) of a  Russian scientist who expects “the coldest winter in a thousand years, because the Gulf Stream has weakened.” Others believe that winter will be cold because of unusually extensive snow cover over the northern part of Russia in the late autumn; heavy snow forms the high pressure that tends to move across to Norway.

Erik Kolstad, climate scientist at Bjerknessnteret (The Bjerknes Centre for Climate Research (BCCR) said

“I think most of the last theory, but dare not say anything about what kind of winter we have in store: – there are so many things that influence winter climate that it is incredibly difficult to notify in advance.  Right now the NAO is slightly negative, and a warning from U.S. researchers suggests that it may remain so for a while. But beyond that it is impossible to say anything. There does not appear to be anyone who dares to create alerts for an entire winter season any more” said Kolstad to yr.no.

In Sweden the press also picks up the theme – from Svenska Dagbladet “The North Atlantic Oscillation (NAO) is in a negative phase, which, before last year’s winter had not occurred in years.  The previous default mode was an NAO positive phase with the warm southwest winds which resulted in mild, almost snow-free winters in northern Europe. 

“Now it looks like last winter. If it continues, it means cold.  But you never know when the market turns” said meteorologist and researcher Per Kållberg at SMHI. Meteorologists around the world are now discussing how long the negative phase continues.  It started in December 2009 and has persisted since then, which is the longest period of 40 years, according to Sydsvenskan (Southern Swedish newspaper and website).  “The fascinating thing is that [we have] known about this phenomenon for a long time but have no idea why it occurs” says Per Kållberg.

On Wednesday northern Lapland had minus 36.6 degrees – the season’s lowest temperature so far, according to SMHI.  It is also the lowest November temperature in Sweden since 1995, when it was minus 37.0 degrees in Central Lapland.

Going back to the Norwegian seasonal forecast, the Met.no site helpfully explains the origins of the forecast:

  • The starting point is 40 different projections (“ensemble”) from the European weather center (ECMWF) in Reading, England.
  • Out of these, the deviation from what is normal temperature. (Deviations are called “anomalies”).
  • When deviations are estimated, are calculated the mean value (in our case the most probable temperature) for a specific location (ie Oslo).  40 calculations are thus boiled down to a value / a forecast.

The European Centre for Medium-Range Weather Forecasts (ECMWF) is funded by 33 countries.  The UK contribution is 16% of the £37M for 2010.  So does this mean it was the ECMWF that was at fault for the BBQ Summer, but that the Met Office just took the flak for it? Or was it the Met Office interpretation for the UK?

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9 Responses to Snow in UK; Scandinavia freezes, but mild winter is forecast

  1. Pingback: Snow in UK; Scandinavia freezes, but mild winter is forecast … - weather information

  2. ArndB says:

    This is a good summary of the current Northern Europe (NE) situation, and the question, whether the coming winter will be as severe as the last winter.
    Two or three cold winters in succession is not the rule in NE. One of the exception had been the war winters 1939/40, 1940/41, and 1941/42. It will therefore be interesting to see, whether the next winter has any similarities to the 2nd war winter 1940/41. This winter had a particularly special aspect, because the Skagerrak area became the cold centre in a very cold NE winter, only few months after the Germans had ambushed Norway, and the sea along the coast from Oslo to Narvik had been the battle ground for uncountable naval warfare events.
    More here: “Norway’s extreme winter 1940/41. Cold pole Skagerrak! Did man contributed? “ at: http://www.what-is-climate.com/
    Could Per Kållberg at SMHI explain the current situation better if he and his colleagues had meanwhile investigated the mentioned three war winters thoroughly?
    Fine weekend

  3. tonyb says:

    Arndb

    You are correct of course, three cold winters in a row is unusual, so if this coming winter IS cold that will be significant

    Tonyb

  4. E.M.Smith says:

    “The fascinating thing is that [we have] known about this phenomenon for a long time but have no idea why it occurs” says Per Kållberg.

    But the science is settled… gotta love it 😉

    Very nice post. I tend to forget about the NAO and it’s impacts on Europe so it’s nice to be reminded of it from time to time from someone in the middle of it.

  5. John F. Hultquist says:

    When sliding down hill, tap the brakes and spin the steering wheel. Done just right this will swap ends and you get to slid through the traffic intersection backwards. Even more fun.

    Well, a very interesting compilation of material. We just had a day of record cold in Washington State east of the Cascade Mountains. Now it is back to just being normally cold.

    A loop of the jet stream was going down the west coast and then turning and going northward east of us. The air flow here was just a bit west of south. This pulled the cold air from B.C. and Alberta directly into our area. This was the same flow Pamela wrote about on WUWT. A very minor shift has now occurred and our flow, such as it is, is from the west with swings also out of the southwest. There isn’t much excitement in the forecast for a week and then there might possibly be a nice weather-maker coming at us from the North Pacific.

    For the next three months, with La Niña averages as the basis, our region is expected to get lots of snow if the majority of storms come from off the Pacific, or much cold if the drier air is pulled south out of Canada (as last week).

    . . .there are so many things that influence winter climate that it is incredibly difficult . . . , said Kolstad.

    For your area, my advice is to watch the loops in the jet stream, which, at the moment, seems to be pulling cold air south along the coast of Greenland into the mid-North Atlantic — also, westward across northern Sweden and Norway bringing the very cold mentioned in the post.. Thus, northern G.B. has been getting, in effect, a “lake effect” snow.

    I have lots of warm clothes and plenty hay for the horses. I look forward to the next three months, and expect frequent updates here.

    Thanks, for the work.

    • Verity Jones says:

      “When sliding down hill, tap the brakes and spin the steering wheel. Done just right this will swap ends and you get to slid through the traffic intersection backwards. Even more fun.”
      Hmm, might have to go out at 2am and try that – it is about the only time that busy intersection is quiet.

      [Update – nah – not so much fun with anti-lock brakes]

      “For your area, my advice is to watch the loops in the jet stream, …. northern G.B. has been getting, in effect, a “lake effect” snow. “
      My family are inveterate weather watchers (due to sailing, skiing etc. over the years). Our main moan is the dumbing down and generalisations of the broadcast forecasting over the years – the BBC seem to wish to appeal only to the lowest common denominator of viewing audience. I find the Jet Stream is something that people readily grasp and its position affects our weather to a great extent. It only rarely gets a mention when we have a blocking event such as now, such that finding additional sources of info on the web has been a great interest for several years now. I really never thought of it as ‘lake effect snow’, but of course it is!

      “I look forward to the next three months, and expect frequent updates here.” Well, I’ll do my best 😉

  6. gallopingcamel says:

    You have to remember that record cold temperatures are “Weather” while record hot temperatures are “Climate Change”.

    • Esop says:

      That is correct as long as the global average temperature is at the highest in the record, as it is now (even in the UAH satellite record).
      If the global average temp anomaly was extremely cold, things would be different.
      BTW, the typical London weather escaped to Greenland: up to 16C and raining over there.
      We’ll see how long the NAO stays negative, it could be a semi permanent mode now, or it could flip back when the Arctic freezes back up in a few weeks, and the La Nina starts having its real impact.

      [Reply – yes Nuuk did have London weather in the second half of November although all stations seem to be back to freezing or just above. Of course the Danish Meteorological Instute figures show Greenland warmed from 1870 to 1930 but is currently no warmer than the 1930s: http://www.dmi.dk/dmi/index/klima/klimaet_indtil_nu/temperaturen_i_groenland.htm ]

  7. Esop says:

    Since Tromsø (Norway) is mentioned in the article, it is interesting to note that the current conditions are +3C and rain. Forecast for tomorrow, Dec 2nd is +4C and heavy rain. For those not quite into Norwegian geography: Tromsø is located well north of the Arctic circle.

    [Reply – not surprising really with 35km/h SW winds and the sea at ~5C, meanwhile UK gets NE winds from Norway, also moderated by crossing the North Sea]

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