Met Éireann names Storm Clodagh

28 11 2015

The current unsettled spell of weather continues and the low pressure system that is forecast to affect Ireland and the UK on Sunday has been officially named Storm Clodagh by Met Éireann.

This makes it the third officially named storm of the joint Met Office Met Éireann pilot project to name storms that affect the UK and Ireland through the autumn and winter 2015/16.

Storms can be named by either the Met Office or Met Éireann.

Met Éireann named the storm on Saturday 28 November having issued an Orange warning for severe gales across Eire for Sunday.

The Met Office has issued a yellow be aware National Severe Weather Warning for wind for a medium likelihood of low impacts from severe gales across some parts of Northern Ireland, Wales, England and parts of southern Scotland.

Pressure chart for Sunday 29 November 2015 at midday

Pressure chart for Sunday 29 November 2015 at midday

The strongest winds are expected to reach Northern Ireland around dawn on Sunday, and most areas by the end of the morning, before gradually subsiding from the west during the afternoon and evening.

There remains some uncertainty with the track of this low and the precise wind speeds and areas to be affected. You can keep up to date with the latest on our forecast pages.

What are the prospects for the weather in the coming winter?

29 10 2015

Anyone who has read the newspapers lately can’t have failed to notice this winter’s weather is in the headlines. Justification for claims of a ‘big freeze’ has come from sources as diverse as the plucky Bewick Swan settling into the comfort of the WWT reserve at Slimbridge, Gloucestershire earlier than ever before, to the strong El Niño and cool North Atlantic Ocean.

But what can we genuinely say about prospects for the coming winter, and what is the influence from phenomena like El Niño? Jeff Knight, from the Met Office Monthly to Decadal Prediction team explains.

In the Met Office we produce outlooks for the UK weather as a whole over three monthly periods. These outlooks are not forecasts in the conventional sense, although they are still made using computer prediction models. While a forecast might say ‘it will rain tomorrow’, the chaotic nature of the atmosphere beyond a few days ahead leads to growing forecast uncertainty, making it meaningless to try to make the same kind of forecast for a day in three months’ time.

Fortunately, atmospheric chaos is only part of the story and, when we consider the broad characteristics of the weather over a three month period, we can see influences from a range of global climate factors that we can endeavor to predict. While the unpredictable part means there is always a range of possible outcomes, the part we can try to predict allows us the opportunity to identify which types of weather are more likely than others. As a result, our outlooks are more useful for professionals who need to assess risk, such as contingency planners, than the public generally. Our current outlook covers the period from November to January.

So what are the global drivers that might influence our weather this winter?

El Niño is the biggest news story currently in global climate. This episodic warming of the waters of the equatorial Pacific Ocean occurs every few years – the last event happened in 2009-10. This ocean warming covers an area about 1,000 km wide and 13,000 km long, stretching along the equator from the South American coast to the West Pacific. El Niño events release a vast quantity of oceanic heat into the atmosphere so it is not surprising that El Niño has effects on weather across the globe.

This year’s El Niño started to grow in April and it has now become a strong, mature event similar to the landmark 1997-8 event. Typically, growth will peak around the end of the year and decline during the first half of the following year. We have already seen its effect on global weather systems: this summer’s Indian monsoon rainfall fell to drought levels and very hot, dry conditions in Indonesia have contributed to widespread forest fires.

Currently, the outlook for El Niño is for further growth over the next two months. Events are often ranked in terms of sea surface temperatures in Central Pacific, and by this measure, this year’s El Niño is more likely than not to become the strongest on record. Temperatures further east near to South America are likely to be not quite as exceptional as in 1997-8. No two El Niños are identical and even very similar events have slightly different characteristics.

What does El Niño imply for the UK this winter?

Unlike some parts of the world, the effect of El Niño on Europe is relatively subtle. In El Niño years there is a tendency for early winter to be warmer and wetter than usual and late winter to be colder and drier. Despite this, it is just one of the factors that influence our winters, so other influences can overwhelm this signal – it is relatively straightforward, for example, to find years where these general trends were not followed.

What about the Atlantic Ocean?

Closer to home, sea surface temperatures to the west of the UK have been notably lower-than-average in recent months. While it is true the westerly winds that we typically get in winter would have to pass over this region, it is unlikely that this will directly have a strong bearing on expected temperatures. This is because temperatures at this time of year are strongly affected by the direction of the wind. Eastern Europe and Scandinavia are 10-20°C colder than the Atlantic Ocean in winter, so our weather will depend much more on how often winds blow in from the north and east than whether the Atlantic is 1-2°C cooler than usual.

More broadly within the North Atlantic Ocean, sub-tropical temperatures to the south of this cool region are widely above average. This combination results in an increased north-south temperature gradient, which is expected to provide greater impetus for Atlantic depressions. For the UK, this would favour relatively mild, unsettled weather conditions.

Global sea surface temperature anomaly 28 October 2015

Global sea surface temperature anomaly 28 October 2015

Our weather is also affected by changes in the stratosphere

European winters are also sensitive to what is happening in the stratosphere, the layer of the atmosphere between 10 and 50 km up that lies above the weather. The equatorial stratosphere is home to the Quasi-Biennial Oscillation (QBO), a cycle that sees winds switch from easterly to westerly and back roughly every 27 months. First noted by Met Office scientists over 40 years ago, the link with European winter weather has stood the test of time. This year, the QBO is in a westerly phase, which implies an increased chance of a mild and wet winter at the surface.

A considerable part of the year-to-year differences between UK winters is related to the occurrence of sudden stratospheric warmings (SSWs). In these events, the polar stratospheric vortex – the fast moving circulation of stratospheric air that whirls around the North Pole in winter – abruptly breaks down. They occur one winter in two on average, and events are most common in January or February. In the majority of cases SSWs lead to the establishment of cold easterly flow at the surface across Europe and the UK. The last SSW was in January 2013, and this event contributed to the cold late winter and early spring in that year.

Whether we get an SSW or not depends on a number of influences, such as El Niño and the QBO. Currently our models suggest an increased likelihood of an SSW from January onwards. If this were to happen, its effects would not be felt much before the end of our November to January outlook period. At the moment, therefore, this is still a long way off, and we consider this suggestion to be tentative.

So what can we expect in the UK this winter?

Most of the global drivers discussed above tend to increase the chances of westerly weather patterns during our November to January outlook period. Our numerical prediction model, being sensitive to these drivers, also predicts a higher-than-normal chance of westerly conditions. This results in an outlook for an increased chance of milder- and wetter-than-usual conditions, and a decreased chance of colder and drier conditions, for the UK. Our outlook also indicates an increase in the risk of windy or even stormy weather.

It should be noted that these shifts in probability do not rule out the less favoured types of weather completely. Also, a general tendency for one type of weather over the three months as a whole does not preclude shorter spells of other types of weather.

Finally, there are hints that the outlook might be rather different in the late winter, with an increased risk of cold weather developing. Nevertheless, it is currently too early to be confident about this signal.

How much does the weather influence what we put in our grocery basket?

14 10 2015

What do you think determines what we buy when we go food shopping? Whilst the odd item may catch our eye and lead to one of those ‘impulse purchases’, British consumers can in some ways be rather predictable when it comes to what influences their choices.

For example, when Christmas comes around, it isn’t hard to predict that we’re going to be looking for turkey and sprouts. And when the economy is doing well, the chances are we’ll be buying a few more bottles of expensive wine.

But one of the most important factors – in fact one which around half of the decision makers at UK retailers and suppliers would count in their top three – is the weather. And whilst Santa’s sleigh may come to town once a year like clockwork, us Brits – more so than most – know that the weather doesn’t quite work in such a predictable manner.


The weather can have a significant impact on what we choose to buy when in store, and ultimately on retailer performance. For example, a four degree increase in temperature can lead to sales of burgers increasing by nearly half, according to one leading supermarket.

When the weather changes, retailers risk losing millions through low stock levels, empty shelves and disappointed customers. It can lead to unexpected fluctuations in store footfall and sales, shortages in availability, and impact the costs and efficiencies of the whole supply chain – this is particularly true for fresh, chilled and seasonal products.

We wanted to understand a bit more about how the UK grocery sector as a whole accounts for the weather in its planning, so we have developed a new report based on opinions of key executives and managers across over 200 food suppliers and retailers in the UK. The report looks at just how much the weather impacts their business – and how they use weather products to make those all-important stock predictions. After all, no one likes going to the supermarket to find that their favourite food item is sold out.

Do swans herald snow for the UK?

13 10 2015

There has been some speculation that the UK may be in for a cold winter after the arrival of a migrating Bewick’s swan from Russia.

The swan arrived at the WWT Slimbridge Wetland Centre in Gloucestershire on Sunday 11 October, the earliest date since records began at the site in 1963.  It is thought low temperatures, snowfall and north easterly winds in Russia have encouraged Bewick’s swans to start their westwards migration through Europe early this year. The swans have also been spotted gathering on lakes in the Netherlands.

First Berwick's swan spotted in Gloucestershire. Credit: MJ McGill

First Berwick’s swan spotted in Gloucestershire. Credit: MJ McGill

WWT studies have shown that the weather is a major influence on when Bewick’s swans migrate from Russia, with the wind direction being a particularly crucial factor.

Unusually cold weather has developed over a large part of continental Europe and is likely to persist through this week with temperatures around 5-10 degrees below average. Daytime temperatures in Russia on Monday were around 3-4C which is more like the average nightime temperature for this time of year. The cold weather is extending further west and south going as far south as the Mediterranean coast of France and north east Spain. Snow has fallen over southern Poland, western Ukraine and eastern Slovakia.

Eur Coldwave 131015


WWT’s Julia Newth said:
“Apparently there’s a Russian saying ‘the swan brings snow on its bill’, because they tend to move just ahead of the cold weather. Of course, we can’t infer much from the arrival of a single swan but it’s certainly exciting this bird has arrived so early.
“It’s only a year old and, because it’s made it all the way here on its own, we assume that it must have come to Slimbridge last year as a cygnet with its parents. We record all the Bewick’s swans that come to Slimbridge each winter by their unique bill pattern as part of our study and give them a name. This one needed a name, so we’ve called him Record Breaker.”

The public can see the Bewick’s swans at WWT Slimbridge where they are fed daily from November 1 to the end of February. They can also be seen via the webcam.

Will the cold weather in Europe affect the UK?
High pressure is currently dominating the weather over the UK with winds from the east bringing cold air. Many places will stay dry with bright days and chilly nights with temperatures around, or a little below, average for the time of year. However, there will be some showers, especially along eastern coasts and in the southeast of England over the next few days.

Eur Cold 131015

There is no sign of any snow for the UK, but low overnight temperatures will allow some localised frost and fog to form. Take a look at our forecast pages for the latest weather for your area. At this stage it is too early to speculate what weather this winter may bring to the UK.

What do we know about the coming winter?

15 09 2015

There has been some speculation in the media today that we may be in for a long, bitterly cold winter because an El Niño is under way in the tropical Pacific.  However it is still far too early to speculate about what sort of winter the UK will have.

During an El Niño sea surface temperature in the east Pacific warms, altering weather patterns around the globe.  The influence of an El Niño over the UK and western Europe tends to be weaker and less predictable than elsewhere because of how far away we are from the event itself.  There is a link in late winter, when we can see a slightly higher risk of a colder than usual end to winter in El Niño years.

This map shows the effect El Nino has on temperatures around the globe.

This map shows the effect El Nino has on temperatures around the globe.


That’s not where it ends when looking at the UK winter, though. Other factors also have an influence, such as sea surface temperature in the North Atlantic, the Sun’s output, and changes in winds high in the atmosphere above the Equator known as the Quasi-Biennial Oscillation. These could wipe out the influence from El Niño, and all of them need to be taken into account to predict the winter.

Scientist and Manager of Met Office Predictability Research, Dr Doug Smith, said: “We continue to make improvements in the developing area of long-range forecasting but with all the competing influences in the climate it remains too early to predict the coming winter with much confidence.”

Our 30-day forecasts remain the best way for the public to get a long-range look at the weather we’ll see, while our detailed 5-day forecasts and warnings will keep everyone up-to-date for any periods of severe weather.


A very sunny winter on the cards

18 02 2015

Early figures show that while this winter is on track for fairly average temperatures and rainfall, it could be among the sunniest in our UK record dating back to 1929.

If we have average sunshine for the rest of February, it’s likely to be in the top few sunniest winters and could potentially beat the 2001 record of 189 hours.

Between 1 Dec -16 Feb many areas have already received more than their long-term average winter sunshine for the full season (1 Dec – 28 Feb), especially parts of the Midlands, eastern Scotland and north-east England.

December and January were both sunny across much of the country – especially eastern areas, while northern England and eastern Scotland have had a sunny February so far.

As we near the end of winter it looks as though temperatures will be close to the long-term average with December warmer than average, January near average and February so far being just below.

For many it has been a dry winter so far across southern, eastern and north-east England but relatively wet across Scotland, with the north-west having a wet December and January.

Dry start to February

The first half of February has seen some dry settled weather thanks to high pressure dominating the weather for much of the period.

Using figures from 1-16 February, temperatures have generally been around 1 to 1.5 °C below normal across the UK as a whole and clear skies have allowed fog and frosty conditions to develop at times.

Many areas have been on the dry side, with less than 20 percent of expected rainfall so far across large swathes of the country – we’d normally expect around half of the monthly average to have fallen by now.

Sunshine amounts have been variable but parts of northern England and eastern Scotland have already received almost the whole-month average.


One year on – A look back to last winter

17 02 2015

This weekend marked the one-year anniversary of the Valentine’s Day storm, which also marked the end of a particularly stormy three-month period. A new review article – ‘From months to minutes – exploring the value of high-resolution rainfall observation and prediction during the UK winter storms of 2013/2014’ – written by 16 Met Office co-authors reviews the accuracy of our forecasting and warning of severe weather during winter 2013-14, and assesses its performance.

The paper concludes that the “prolonged period of high impact weather experienced in the United Kingdom during the winter of 2013/14 was very well forecast by the operational tools available across space and time scales.”

Here Huw Lewis, the paper’s lead author, and Derrick Ryall, Head of the Public Weather Service, look at the extreme weather last year and the role of the Met Office in communicating severe weather through the National Severe Weather Warning Service.

Analysis chart 1200 GMT 26 January 2014

Analysis chart 1200 GMT 26 January 2014

Winter 2013/2014 in the United Kingdom was remarkable. The country was battered by at least 12 major winter storms over a three month period and was officially assessed as the stormiest period that the United Kingdom has experienced for at least 20 years.

The series of storms resulted in the wettest winter in almost 250 years (according to the England and Wales precipitation series from 1766), significantly wetter than the previous wettest winter in 1914/1915.

Snapshot of UK rain radar surface rainfall rate for 2200 GMT on 23 December 2013

Snapshot of UK rain radar surface rainfall rate for 2200 GMT on 23 December 2013

The extreme weather caused widespread flooding throughout Southern England and coastal damage – most notably in the South West and Norfolk coasts. The impact of the severe winter storms on individuals, businesses and the government were substantial, including several fatalities, widespread power cuts and damaged infrastructure.

Recent advances in forecasting, technology and the scientific developments in meteorology have been considerable. These developments and improvements in accuracy mean that a four-day weather forecast is as accurate as a one-day forecast was just thirty years ago. During the course of last winter, the Met Office was able to use these forecasts to warn of any severe weather well in advance. In the case of the St Jude’s Day storm at the end of October 2013 warnings went out to the Government and the public five days before the storm even existed.


As the accuracy of weather forecasts has evolved, so has the communication of the potential impacts of severe weather. The National Severe Weather Warning Service enables more ‘weather decisions’ which in turn help to minimise the consequences of severe weather. The Met Office was at the heart of the government response to the storms, providing advice on weather impacts through the National Severe Weather Warning Service and Civil Contingency Advisors. The Met Office also worked very closely with both the national and regional media, who in turn played a key role in ensuring that the public were fully informed about the potential impacts of any up-coming weather.

In addition to the Public Weather Service, commercial partners and customers were also provided with detailed updates throughout the period in order for them to plan effectively for logistical issues. Together, these advanced warnings helped authorities, businesses and individuals to be better prepared to take mitigating actions.

Driving further improvements in accuracy and therefore reducing the lead time and increasing the detail of severe weather warnings is one of the Met Office’s key priorities . The ultimate aim is to improve the potential for users to plan preventative measures for severe weather events much further ahead. Underpinning all of these developments is a continuing programme of scientific research and access to enhanced supercomputing over the next few years.

Very strong winds recorded over northern parts of the UK

9 01 2015

As forecast by the Met Office, a powerful low pressure system passed to the north of the UK in the early hours of this morning bringing exceptionally strong winds in places.

Two low level stations recorded wind speeds of over 100mph, with the gust recorded at Stornoway being the joint strongest recorded at the site (the other gust at that speed was recorded on 12 February 1962).

While the winds have now dropped significantly, it will stay windy through today in many parts and gusts will increase in strength once again tonight as another low pressure system is set to affect northern parts of the country. You can see detail on this on our forecast and warnings pages.

Below are some of the maxiumum gust speeds recorded during the first storm, between 10pm last night and 9am this morning.

Date and time Station Area Speed (mph)
09/01/2015 04:00 ALTNAHARRA SUTHERLAND 97
09/01/2015 06:00 WICK AIRPORT CAITHNESS 93
09/01/2015 03:00 ALTBEA ROSS & CROMARTY 90
09/01/2015 05:00 KINBRACE SUTHERLAND 87
09/01/2015 01:00 SKYE WESTERN ISLES 86
09/01/2015 07:00 KIRKWALL ORKNEY 86

The strongest wind in England was at High Bradfield, in South Yorkshire, which saw a gust of 76 mph at 1am this morning.

In Wales, the strongest gust was at Aberdaron, Gwynedd, with 76mph at 11pm last night.

For Northern Ireland, the strongest was 70mph at Killowen, County Down, at 10pm last night.

Winds are almost always stronger at our high level weather stations (those that are sited at 500 metres of altitude or higher), which are also often very exposed.  For this reason the winds from those sites are unlikely to reflect what the vast majority of people are experiencing. Bearing that in mind, the strongest gusts from the high level sites are quoted below for reference:

Date and time Station Area Height (metres) Speed (mph)
09/01/2015 04:00 CAIRNGORM SUMMIT INVERNESS-SHIRE 1237 140
09/01/2015 00:00 AONACH MOR INVERNESS-SHIRE 1130 129
09/01/2015 04:00 BEALACH NA BA ROSS & CROMARTY 773 124
09/01/2015 05:00 GREAT DUN FELL CUMBRIA 847 107
09/01/2015 05:00 GLEN OGLE PERTHSHIRE 564 102

White Christmas?

26 12 2014

Most people woke up yesterday to a green Christmas rather than a white one.

Snow was recorded at our observation site at Lerwick and some sleet was also recorded at Wick between 11am and 12pm, however for the rest of the UK it remained dry and clear throughout Christmas Day.

To find out what the forecast for your area is for the next five days visit our website:

A closer look at ‘weather bombs’

10 12 2014

With strong winds affecting parts of the country today, there has been a lot of talk about ‘weather bombs‘ – but what are they and what do they mean for our weather?

First of all, it’s important to stress the UK is not being ‘hit’ by a weather bomb – the track of the low pressure system is well to the north of the UK, on roughly the same latitude as Iceland. We’re feeling its influence remotely.

This means we are not getting the very strongest winds associated with this system, but far north-western parts of the UK are seeing winds in the 70-80mph range as forecast. Further south the winds are much less strong – so London, for example, is unlikely to see even gale force gusts and mean wind speeds will be much lower.

Another point is that the ‘bomb’ element, the rapid deepening of the low pressure as explained below, happened on Monday – and its now just like any other powerful Atlantic low. In fact, the weather we’ll experience today is nothing unusual for the time of year.

Chart showing a low pressure in the north-west Atlantic at midday on Monday 8 December.

Chart showing a low pressure in the north-west Atlantic at midday on Monday 8 December.

Chart shows the same system 24-hours later, with a 26 millibar fall in pressure.

Chart shows the same system 24-hours later, with a 26 millibar fall in pressure.

So what is a ‘weather bomb?’

A ‘weather bomb’ is more usually referred to as ‘explosive cyclogenesis’ and is a meteorological term describing the rapid fall in central pressure of a depression (or low pressure) – it has to fall by 24 millibars in 24 hours in our latitudes to meet the criterion.

In many ways a ‘bomb’ can be seen as simply a more powerful, more intense version of the kind of Atlantic low pressure systems that normally affect the UK.

Climatologically speaking, explosive cyclogenesis events, or bombs, tend to occur most frequently over sea near major warm ocean currents, for example over the North Atlantic Ocean near the Gulf Stream or over the Western Pacific Ocean near the Kuroshio Current.

An explosive cyclogenesis event in these regions would then tend to happen as a particularly intense jet stream (which is a narrow band of strong winds high up in the atmosphere) interacts with an existing, and often weak, low pressure lingering near one of these warm ocean currents.

In other words, as with so many things in meteorology, it is the coming together of multiple ingredients that allow a ‘bomb’ to develop.

How many ‘bombs’ a year – and what is the impact?

There are gaps in the global observational record, so it’s difficult to give a definitive number of how many ‘weather bombs’ are seen globally each year. However, recent estimates based on a twenty to thirty year dataset suggest there are somewhere between 45 and 65 explosive cyclogenesis events per year, with more ‘bombs’ occurring in the northern than southern hemisphere.

Of course, it’s important to realise that the definition of a ‘bomb’ is somewhat arbitrary and ‘just a number’; a depression deepening only slightly less than 24hPa in 24 hours will still be a powerful depression more than capable of producing severe weather.

Another important point is that the track a ‘bomb’ takes relative to the British Isles, and at what stage of its development it does so, are key to its impact on UK weather – in general the closer the ‘bomb’ tracks to the British Isles the more severe the weather.


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