What’s in store this winter? Responding to the headlines

12 11 2012

It seems that it is the time of year for colourful headlines about an impending big freeze. We had them at this time last year, which prompted our Chief Executive to write an opinion piece in The Times.

Now we have very similar stories again, with the front page of the Daily Express declaring ‘Coldest winter freeze on way’ and warning that temperatures are set to plunge as low as -15C.

There have been other stories elsewhere along similar lines, with some saying that the Met Office is briefing the Government about a cold winter ahead.

So what are the facts behind the headlines?

Some of the stories have taken a cue from parts of our current 30-day forecast. Today’s forecast for 26 November to 10 December reads as follows:

As is usual, there are uncertainties in the forecast for this period, but there are signs that the changeable conditions will continue through the start of this forecast period. There is also a signal for temperatures to be close to or just below the seasonal average. Into December, although there are no strong indications that any particular weather type is going to dominate, on balance colder, drier conditions than at present are favoured, rather than milder, wetter weather, especially across the southern half of the UK.

However, perhaps what the newspapers have failed to pick up on and report to their readers is that there is still a great deal of uncertainty about exactly what weather we will see – as there often is when looking at timescales of over five days ahead.

The science does not exist to make detailed forecasts for temperature and snowfall for the end of this month, let alone for December or even the winter as a whole.

With regards to us ‘briefing the Government on a cold winter’, this is related to our three monthly outlook for contingency planners.

This is a complex product designed to help contingency planners making long-term strategic decisions based on risk exposure. However, it’s not useful for most other people as it doesn’t give one forecast for what’s ahead – rather it outlines potential scenarios and their associated probabilities.

It’s worth noting that while contingency planners use our three month outlook to inform long-term decisions, they make their operational decisions on our five day forecasts and warnings.

These will always provide the best possible guidance on any periods of cold weather, frost or the likelihood of snow, giving detailed local information across the UK.

Ultimately, we’re heading into winter and we expect winter to be colder than the rest of the year – but it’s too early to say exactly what temperatures we can expect or where and when we might see snow.





Turning colder this weekend

22 10 2012

There have been many references in the media to the UK having an Indian summer this week, with temperatures expected to reach 20 °C. However, as forecast by the Met Office many of us woke up today to rather grey, misty and drizzly skies and although temperatures are well above average for the time of year, it certainly doesn’t look or feel summery outside for most of us. We have also seen widespread mist and fog overnight across England and Wales, which the Met Office warned for over the weekend, and further foggy conditions are expected for the next couple of nights.

This morning's satellite image

Visible satellite image from 0900 22 October 2012

So are we going to see any sunshine at all this week? Well, yes, the cloud should break in some places, and we may even see temperatures rise to the high teens along the south coast of England at times, but these temperatures will be short lived.

For most of us it will be the end of the week before the sunshine returns and when it does the weather will be far from warm.

By Friday, much colder air from the Arctic will spread across the UK, bringing drier and clearer weather but much lower temperatures. In fact, daytime highs will struggle to reach double figures by the weekend and there may even be a few wintry showers across north-eastern parts of the UK. It will be cold and frosty overnight too and for many of us this will be the first cold snap of the season.

In this video, Deputy Chief Forecaster Baden Hall explains exactly what we can expect over the next few days.

The latest information about the weather and warnings can be found on the Met Office website, iPhone and Android apps and on twitter. Cold weather can also have an impact on people’s health and you can find out more on the Met Office’s Cold weather and health web pages.





Record low for Arctic sea ice extent

29 08 2012

This week the National Snow and Ice Data Centre (NSIDC) announced that Arctic sea ice extent has reached a new record low since satellite data records began in 1979.

According to the NSIDC, observations show there were 4.1 million square kilometres (1.58 million square miles) of sea ice on 26 August.

Arctic sea ice extent  The black line shows the 1979 to 2000 median extent.  Credit: National Snow and Ice Data Center

This is 70,000 square kilometres (27,000 square miles) less than the previous record low set on 18 September 2007.

The previous record was the sea ice minimum for the year – which normally occurs at the end of summer before cooler temperatures sea ice start to form.

The July 2012 ice extent was the second lowest observed during the satellite era, following the record low observed in 2011. The synoptic conditions during the month were variable, and much of the Arctic was relatively warm with temperatures 1-3 degrees Celsius above the 1981 to 2010 average over the Beaufort Sea and regions to the north. 

By 1st August the daily extent was lower than the previous record low for the time of year recorded in 2007, and has since remained at a record low value. Between 4th and 9th August there was an extremely rapid loss of ice cover in the East Siberian Sea, coinciding with a severe storm over the Central Arctic. This rapid loss of ice cover may have been caused by ice breaking up and melting due to the strong winds generated by the storm, although it is also possible that the melt would have occurred anyway at this time as the ice concentration in this region was already low.   

With this previous record already broken in August, it’s likely this year’s sea ice extent will continue to decline into September. The NSIDC will announce when the Arctic sea ice extent has hit a minimum for this year when this occurs, most likely toward the middle of next month.

Declining trend in sea-ice

Satellite records began in 1979 and have shown a long-term decline in sea ice extent. However, the rate of decline has accelerated in the past 15 years and the last five years make up the lowest five extents in the 32-year record.

Climate models which simulate future Arctic sea ice extent show wide variations, but Met Office results suggest the area could be nearly ice-free in summer as early as 2030.

However, models do not suggest the current accelerated rate of decline would continue or that there was any ‘tipping point’ from which ice extent could not recover.

What are the impacts for the UK?

Long-term changes in Arctic sea ice are likely to have impacts locally in the Arctic as well as driving changes in European and global climate.

As the sea ice decreases, the immediate impact is for a the lower atmosphere in the Arctic to be warmed by the Arctic Ocean – which is relatively warm compared to the ice cover.

However, there is also evidence that depleted sea ice alters atmospheric circulation patterns outside the Arctic throughout the following months and into winter.

This appears to result in high pressure over the Arctic and low pressure further to the south over the mid-latitudes – which in turn tends to drive more easterly winds across Europe, particularly in winter.

While other factors are also involved in determining winter climate, this raises the risk of cold winter conditions over northern Europe.

However, the relative importance of sea ice conditions and other factors in producing cold winters is being investigated by Met Office scientists and others.

You can read more about Arctic sea ice in our research news pages.





Met Office scientists to feature in BBC Horizon programme ‘Global Weirding’

27 03 2012

BBC Horizon will broadcast ‘Global Weirding’ on BBC Two tonight at 9pm, exploring the science behind why the world’s weather seems to be getting more extreme and if these patterns are a taste of what is to come.

Horizon say: “Something weird seems to be happening to our weather – it appears to be getting more extreme. In the past few years we have shivered through two record-breaking cold winters and parts of the country have experienced intense droughts and torrential floods. It is a pattern that appears to be playing out across the globe. Hurricane chasers are recording bigger storms and in Texas, record-breaking rain has been followed by record-breaking drought.

“Horizon follows the scientists who are trying to understand what’s been happening to our weather and investigates if these extremes are a taste of what’s to come.”

The producers of the programme visited the Met Office headquarters and Operations Centre in Exeter to film for the programme at the end of last year, interviewing Adam Scaife, Head of Monthly to Decadal Forecasting and Helen Chivers, a Met Office Forecaster.  In the programme we discuss the science being undertaken here at the Met Office into the effects of Climate Change on ourt weather including the effects of Arctic sea ice depletion on European winter weather, and our role in forecasting extreme weather for the UK.

Adam Scaife and Helen Chivers from the Met Office appear in the programme

Other contributors to the programme include Mike Lockwood (University of Reading) on solar observations, Kerry Emmanuel (MIT) on hurricanes and Katharine Hayhoe (Texas Tech University) on extreme wet and dry conditions in Texas.

This weeks Radio Times also previewed the programme saying:

“This week’s Very Big Number from Horizon: the Met Office’s computer can do one hundred trillion calculations — a second. It needs to, in order to process the gouts of data gathered from satellites, data which means, we’re told, that a five-day forecast today is as accurate as a one-day forecast was 30 years ago. (Were we so long-suffering in 1982?)

All this technology isn’t to feed some quaint British obsession with weather, it’s to keep track of increasingly freakish extremes in meteorology, not just here but around the world: from record rains in Scotland to droughts in Texas and a boom in hurricanes. Scientists are trying to get to grips with it all and Horizon follows them, in one amazing scene, right into the heart of the storm.”





Arctic Conditions return to bring snow disruption and tumbling temperatures

17 12 2010

Arctic Conditions return to bring snow disruption and tumbling temperatures

Following the return of arctic conditions across the UK through yesterday, overnight temperatures tumbled across the UK as significant snowfall brought disruption to parts of Scotland, Northern Ireland and Wales.

Below is a table showing a selection of lowest temperatures observed across the UK last night.

Location Minimum Temp (deg C)
Cairngorm  Siesaws -12.2
Great Dun Fell  Siesaws -10.1
Cairnwell  Siesaws -10
Spadeadam -9.4
Carterhouse -9
Tyndrum  Cdl -8.7
Drumnadrochit -8.5
Tulloch Bridge -8.4
Drumalbin  Esaws -8.2
Bealach Na Ba -8.2
Sennybridge (Samos) -7.8
Glen Ogle  Siesaws -7.5
Warcop Range  Esaws -7.2
Woodford -7.2
Salsburgh -7.2
Redesdale Camp -7.1
Dalwhinnie  Cdl -7.1
Shap Fell  Esaws -6.9
Eskdalemuir -6.6
Leek -6.3
Winchcombe Sudeley Castle -6.3
Tredegar Bryn Bach Park No 2 -6.2
Market Bosworth -6.2
Fylingdales  Codet2 -6.1
Bingley Number 2 -6
Lyneham -5.9
Alice Holt Lodge -5.9
Newton Rigg -5.9
Aviemore -5.8
Kenley (Esaws) -5.8
Bournemouth/Hurn Airport -5.8
Albermarle -5.7
Blencathra -5.7
Loch Glascarnoch -5.6
Braemar No 2 Cdl -5.6
Astwood Bank -5.6
Carlisle  Esaws -5.5
Little Rissington -5.5
Myerscough -5.5
Wattisham -5.4
Cottesmore (Samos) -5.3
Hqstc (High Wycombe) (Samos) -5.3
Rothamstead No 2  Cdl -5.3
Monks Wood  Cdl -5.3
Westonbirt -5.3
Bradford -5.3
Nottingham/Watnall -5.2
Wittering (Samos) -5.2
Keele Cdl -5.2
High Mowthorpe -5.2
Bainbridge -5.2
Threave Cdl -5.1
Lentran -5.1
Goudhurst -5.1
Marham (Samos) -5
Benson -5
Durham  Cdl -5
Newport -5
Herstmonceux -4.9
Wick -4.9
Keswick  Esaws -4.9
Andrewsfield -4.9
Charlwood -4.9
Yeovilton  Samos -4.9
Cranwell (Samos) -4.9
Santon Downham -4.9
Wych Cross -4.9
Bedford  Esaws -4.8
Scampton -4.8
Kinbrace  Cdl -4.8
Rochdale  Cdl -4.8
Hampstead -4.8
Otterbourne Water Works -4.8
Cavendish -4.8
Edinburgh Royal Botanic Gardens -4.8
Lake Vyrnwy  Esaws -4.7
Baltasound -4.7
Coleshill -4.7
Boscombe Down  Samos -4.7
Pershore College Of Horticulture  Cdl -4.7
Norwich Airport -4.7
Craibstone -4.7
Llysdinam -4.7
Ravensworth -4.7
Odiham -4.6
Langdon Bay -4.6
Shawbury (Samos) -4.6
Pershore  Esaws -4.6
Middle Wallop (Samos) -4.6
Writtle -4.6
Leuchars -4.5
Coningsby (Samos) -4.5
Exeter Airport -4.5
Trawscoed  Esaws -4.5
South Farnborough  Esaws -4.5
Liscombe  Esaws -4.5
Wainfleet  Samos -4.5
Dishforth Airfield -4.5
Wisley -4.5

Below is a table showing snow depths recorded at 0900 this morning. With strong winds there has been significant drifting of snow and depths are likely to be significantly deeper in parts of Northern Ireland and Scotland.

Location Snow Depth (cm)
FORRES, HILLHEAD 10
LOUGH FEA 10
ALDERGROVE 9
ORKNEY: LOCH OF HUNDLAND 9
KINROSS 8
KIRKWALL 8
SENNYBRIDGE NO 2 8
CASTLEDERG 8
DYCE 7
AVIEMORE 7
DERRYGONNELLY FSC 7
LINGWOOD, STRUMPSHAW HILL 6
CROMDALE 6
FAIR ISLE 6
REDESDALE CAMP 6
SHAWBURY 5
VELINDRE 4
LERWICK 4
KINLOSS 4
DARWEN NO 2 3
MIDDLETON, HILLSIDE 3
SKYE: LUSA 3
WICK AIRPORT 3
ESKDALEMUIR 3
ROSEHEARTY 3
RONALDSWAY 3
LINTON-ON-OUSE 3
ALBERMARLE 2
YEOVILTON 2
ABERPORTH 2
DUNKESWELL 2
WATTISHAM 1
WITTERING 1
COTTESMORE 1
SPADEADAM 1

 

Map showing snow depths recorded at 0900 am on Friday 17th December

Map showing snow depths recorded at 0900 am on Friday 17th December

 

 

 

 








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