So what happened to our summer?

28 08 2015

Our Chief Scientist Professor Dame Julia Slingo OBE FRS reflects on this summer’s weather and what has influenced it:

No-one can deny that we have had a pretty disappointing summer with a lot of unsettled weather and only a few warm spells, especially through July and August. Our weather has been dominated by low pressure over and to the west of the country that has brought us periods of heavy rain from the south – what we call the Spanish Plume. So what has been happening?

If we look beyond our shores there have been some big changes in the global climate this year. El Niño is in full flight, disturbing weather patterns around the world. The low pressure that has dominated our weather is part of a pattern of waves in the jet stream around the world that has brought crippling heat waves to places like Poland and Japan. And, looking back over past El Niños, you could have expected that a more unsettled summer might be on the cards for the UK. Closer to home the North Atlantic is more than 2 degrees colder than normal. It seems quite likely that the unusually cold North Atlantic has strengthened and pushed our jet stream south, also contributing to the low pressure systems that have dominated our weather.

So could all this have been anticipated? Seasonal forecasts for this summer suggested that temperatures and rainfall would be near normal. However, as the season progressed all the leading models around the world failed to capture the signal for unsettled weather over the UK. We all know that forecasting months and seasons ahead is still in its infancy and much more research needs to be done. On the other hand our day-to-day forecasts have been really successful in allowing us to warn of bad weather, highlighting yet again the benefits of our research that has delivered year-on-year and decade-by-decade improvements in forecasting skill. Our 5-day forecast is now as accurate as our 1-day forecast was when I started my career. This enables us to make so many decisions that keep us safe, protect our property, keep our infrastructure running and even when to go out and enjoy the sunshine!

All of this cannot happen without improvements to research and technology, and this week the first phase of our new supercomputer went live, five weeks ahead of schedule. This will enable us to provide even more accurate and relevant weather and climate forecasts to all of us, our government, emergency responders, and our many other customers at home and abroad.

The news that the BBC has decided that the Met Office won’t be their main weather provider when the current contract ends has raised the question of where will the new provider get their information from. It’s important to understand that no weather forecasting organization, whether it is a National Met Service like the Met Office or an independent company, can provide a service without a forecast, and that it is the leading meteorological agencies, like the Met Office, that build and deliver those forecasts. So whoever the BBC chooses to deliver their weather services in future, you can be sure that Met Office observations and forecasts will continue to be at the heart of them. We are committed to driving forward the skill and usefulness of our forecasts and ensuring that all of us benefit from the advances the Met Office makes in the coming years with our new supercomputer.





Record hot to record cold in a July of extremes

3 08 2015

While this year’s July may not have broken any monthly records – it was book-ended with some localised daily records at both extremes of the temperature spectrum.

The month started with the highest recorded July temperature in our UK climate records with 36.7C recorded at Heathrow on 1 July.

Then on the last day of the month, we saw the opposite extreme – with a number of stations across the UK breaking their lowest recorded July temperature.

Some of these stations have fairly long records – below we’ve highlighted those stations which broke their July low record which have observations going back for 30 years or more.

STATION COUNTY PREVIOUS RECORD PREVIOUS RECORD DATE YEARS OF DATA TEMP 31/07/15
ALICE HOLT LODGE Surrey 3.9 03/07/1984 64 3.5
KEELE Staffordshire 5.2 16/07/2001 63 5
EXETER AIRPORT Devon 3.3 01/07/2011 50 2
CHIVENOR Devon 5.7 07/07/1996 38 5.6
PERSHORE Worcestershire 3 04/07/1965 36 2.7

These temperatures came about after several days of a northerly airflow which brought colder than average air over the UK. Clear skies allowed temperatures to drop rapidly overnight across many spots, leading to some of the localised records.

None of these new station records came close to breaking the all-time UK record for July of -2.5C which was set at both St Harmon (Powys) on 9 July 1986 and Lagganlia (Inverness-shire) on 15 July 1977. It’s worth noting here that lowest daily temperature records exclude stations above 500 metres above mean sea-level.

Other extremes for July 2015 are:

  • The wettest day was recorded at Cambridge Botanic Garden on the 16th, with 87.1mm of rain recorded in 24 hours. This is significantly more than the whole-month average for July at that station, which is 50.7mm.
  • The strongest gust was recorded at the Needles on the Isle of Wight on the 26th, with 60mph.
  • The Sunniest day was on Fair Isle, Shetland, on the 26th, with 16 hours of sunshine recorded.
  • The coldest temperature recorded during the month was a chilly -0.6C at Katesbridge in Down, Northern Ireland on 15 July – although this wasn’t a record for that station.
  • The warmest temperature was 36.7C recorded at Heathrow on 1 July – you can read more about that on our blog.




Summer weather to return as we head into weekend

28 07 2015

More summer-like weather will return to the UK with conditions and temperatures due to improve as we head into the weekend.

This will come as welcome news to many after a spell of disappointing weather over the past few days which has seen prolonged rainfall and some unseasonably strong winds.

Through to Thursday the UK will be seeing a flow of cool air from the north which is helping to keep day and night temperatures slightly below normal. Overnight temperatures in some rural areas could fall to a few degrees above freezing – with a few isolated spots even seeing frost early on Thursday.

This is all set to change, however, as the northerly flow will be cut off to allow westerly winds, and milder air, to push in later on Thursday.

This will enable temperatures to recover to more normal levels for the time of year across many parts of the country, although some cool nights remain likely.

Colour chart showing temperature change over the next few days, with cooler air (green) making way for warmer conditions (yellow/orange).

Colour chart showing temperature change over the next few days, with cooler air (green) making way for warmer conditions (yellow/orange).

At the same time, high pressure is also set to establish across most of England and Wales to bring lighter winds and more in the way of sunshine for Friday

Scotland and Northern Ireland will continue to see some showers, and these may affect other northern areas into Saturday, though conditions will be markedly improved on recent days for many.

Over the weekend, many parts of England and Wales will be mainly dry with sunny spells. In light winds it will feel much warmer than of late, with temperatures back into the twenties across much of central and southern England.

It may also warm up further across southern and eastern areas on Sunday and into Monday.

Malcolm Roughead, Chief Executive of VisitScotland said: “It’s great to hear the weather is improving, however, come rain or shine, Scotland is a beautiful place to explore! Our surveys continually show that the weather is of little consequence to visitors. Whether it’s stormy clouds over the mountains of Glencoe or blue skies over coral beaches in Skye, visitors are in awe of the breathtaking scenery and visit and re-visit in their droves for the landscapes, cities, culture and friendly people.”

“With lots of exciting events and activities planned across the country including, of course, the world-famous Edinburgh Festivals next month, we know visitors will have an experience of a lifetime in Scotland this summer regardless of the weather.”

James Berresford, Chief Executive for VisitEngland, said: “The forecast of good weather is great, especially with the summer season upon us. The release of our latest figures today reveal a strong performance for domestic tourism in the first quarter of this year so we hope this will continue over the summer months. We know holidays in England generate high levels of satisfaction for visitors, and with world class indoor and outdoor attractions, fantastic events and festivals across the country there is still time to plan a last minute short break or day trip in England whatever the weather.”

While we will have a spell of good weather and more summer-like temperatures for many into the weekend, it looks as if more unsettled conditions will move in from the west later on Sunday. These conditions will spread slowly east on Monday, with all areas seeing more unsettled conditions by Tuesday.

Temperatures are likely to be closer to normal by then.

Stay up to date with our forecasts to see how the wather is set to improve in your area.





Mixed bag for the start of June

17 06 2015

It has been a very varied weather picture so far this month.

It’s been dry and warm for the south east of the UK, with some places around London having received less than 5 mm of rainfall so far and areas such as Essex, Hertfordshire, Suffolk and Cambridgeshire receiving less than 20% of the month’s average in places.

This year’s highest UK temperature so far, 26.8 °C, occurred at Kew Gardens (Greater London) on the 12 June.

Much of the rest of the UK has seen temperatures in general noticeably below average for June, continuing on from the rather cool May.  While rainfall totals are already close to the whole-month average in the central Scottish Highlands and in Nottinghamshire.

MeanTemp June

June began with two very unseasonal days, due to a deep low-pressure system to the west of the UK, bringing large amounts of rain and some strong winds to the UK, particularly southern areas. Apart from this, and some showery rain on the 5th/6th,

June so far has been relatively settled, especially over southern areas, although we saw a period of thundery outbreaks on 12th June affecting mainly southern areas due to a plume of very humid and warm unstable air moving in from France/Spain.

Mean temperatures for the UK so far this month have been 2 °C below normal in most areas, but colder in the far north-west of the UK and a little closer to normal in southern England. While the minimum temperatures have been well below average, by as much as 3 °C over some northern areas.

mean temperature sunshine duration rainfall
1-15 June 2015 Act (°C) Diff from avg (°C) Act (hrs) % of avg Act (mm) % of avg
UK 11.2 -1.8 117.6 69 31.3 43
England 12.5 -1.6 128.3 70 23.1 37
Wales 11.6 -1.6 121.6 70 41.8 49
Scotland 9.3 -2.0 99.3 66 43.9 49
N Ireland 10.3 -2.5 114.3 76 21.4 28

We would expect figures to be around 50% of the average figures by the mid month point.

For the latest weather forecast go to www.metoffice.gov.uk/weather





Stark weather contrasts across the USA

18 02 2015

While the UK continues to see fairly typical winter weather, over the other side of the Atlantic the US is experiencing some stark contrasts.

While some parts in the west are seeing warm and dry conditions, eastern areas are seeing very cold weather.

This week will see a continuation of warmer-than-average conditions in western parts of the USA, with little or no rainfall in the forecast.

Map showing air temperatures across the US, with white (-24C) and blue (below 0C) showing cold air and yellows and oranges showing warm air. From the Met Office's Global Model for 1200HRS GMT on 20 February 2015

Map showing air temperatures across the US, with white (-24C) and blue (below 0C) showing cold air and yellows and oranges showing warm air. From the Met Office’s Global Model for 1200HRS GMT on 20 February 2015

Despite some welcome rainfall at the start of February, California remains in drought, with a large swathe in exceptional drought – which is the highest category that the US Drought Monitor report.

In San Francisco, no rain fell at the downtown observation station or the airport during the whole of January 2015. This is the first January without rainfall since records began in 1850. Normally January is the wettest month of the year, with an average 119mm.

The dry conditions have also resulted in the Sierra Nevada snow pack being at less than 50% of where it should be as we head towards the end of winter.

Meanwhile, the very cold spell of weather is expected to continue across a large part of eastern and northeastern USA, with air originating from the Arctic keeping things icy.

There will be some snow at times, although not as significant as some recent events, though localised heavy ‘lake effect’ snow is likely this week off the Great Lakes.

However, the most noteworthy element will be the extreme cold. Another arctic front will arrive across the East Coast, bringing exceptionally cold conditions.

Places from the Carolinas to the Mid-Atlantic may see some of the coldest weather since the mid-1990s, with numerous record low temperatures expected.

In fact this cold air is expected to reach as far south as Florida, with even the Caribbean expecting well below average temperatures throughout the rest of this week.





A wet and sunny January, but very average for temperature

4 02 2015

January 2015 saw above-average amounts of sunshine and rainfall right across the UK, but with temperatures averaging out to near-normal.

The first half of the month was largely unsettled, with mild, wet and windy weather interspersed with colder and drier spells.

From mid month, the colder conditions turned more persistent, with snow in places and some extensive snowfalls across the Scottish mountains.

This change of weather type led to some large temperature variations through the month, with a high of 16.5C at Exeter Airport on the 9th and a low of -13.7C at Loch Glascarnoch on the 19th.

Even though Loch Glascarnoch is in the Scottish Highlands and so is prone to very low temperatures in the winter, this was the lowest temperature recorded across the UK since 2012.

Rainfall amounts were above average across the UK, especially so in Scotland where it was the 4th wettest January in the series since 1910.

Shetland was particularly wet with Lerwick recording over twice the average rainfall; it was the wettest January here in a 100-year series.

Conversely, sunshine amounts were also above average. Nottingham, Waddington and Dyce each recorded their sunniest January in over 60 years of records.

Across the UK, it was the fifth sunniest January since 1910, with 60 hours of sunshine (compared to an average of 47 hours).

January 2015 sunshine anomaly compared to the 1981-2010 average

January 2015 sunshine duration as a percentage of the 1981-2010 average

Despite the cold end to the month, temperatures for the month as a whole were very close to average, with a mean temperature of 3.7C across the UK (just 0.1C above the 1981-2010 average).

Here are the weather extremes that we saw across the UK throughout January 2015:

You can find out more about the weather in January 2015 on the climate pages of our website.





Why are we now seeing colder weather across the UK?

16 01 2015

Over recent weeks, we have spoken about the very strong jet stream across the Atlantic, driving areas of intense low pressure towards the UK. This has bought spells of very wet, windy but relatively mild conditions to the country.

As many of you would have noticed, although the wind and heavy rain has eased, there is now a colder feel to the weather, both by day and night. But what has caused this change in the weather?

Once again the change is down to the jet stream. It has weakened and its track has moved further south, keeping the deep low pressure systems away from our shores. However, now the UK is to the north of the jet stream we are on its cold side, and this has allowed colder weather to feed in across the country.

Current jet stream

Current jet stream across the Atlantic

So what does this mean for us?

As we look ahead into the weekend and next week, the cold weather looks likely to continue. Daytime temperatures will be near or below average and there will be some frosty nights, as temperatures fall below freezing in many areas. We’ll see some sunny spells around and there will also be showers or longer spells of precipitation in places, giving a mixture of rain, hail, sleet or snow, which may settle in some areas.

Because of the threat of wintry weather over the coming days, we encourage everyone to keep up to date with the latest forecasts and national severe weather warnings and to stay weather aware this winter by following the Met Office on Twitter, Facebook, Google+ and YouTube for the latest weather information. You can find information about how to prepare for every aspect of the winter season at Get Ready for Winter.

As we head towards the latter part of the month, we can see some indications that milder weather may return, but there is considerable uncertainty about this so far in advance.





Extreme global weather

5 01 2015

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.





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: metoffice.gov.uk





US snowfall and will it impact the UK?

20 11 2014

Parts of the US and Canada are seeing particularly cold weather and heavy snowfall at the moment.

Chart showing the position of the jet stream over North America as at 00:01 on 20 November.

Chart showing the position of the jet stream over North America as at 00:01 on 20 November.

A southward buckle in the jet stream has seen cold polar air flow south to north eastern parts of North America.

In the Buffalo region of New York state, temperatures have fallen as low as -15C and 4-5 ft (about 1.5 metres) of snow has fallen – enhanced by what’s known as the ‘lake effect’. Another 2-4 ft (about 1 metre) is expected through today.

The snowfall is set to ease on Friday with much milder conditions through the weekend giving a rapid and significant thaw – which could bring a risk of flooding.

This risk could increase through the start of next week when some very heavy rain is expected across the area.

What is lake effect 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

This is an effect which applies to areas around large lakes like those seen in the northern US – Lake Superior has an area of more than 30,000 sq miles.

When cold air moves across the relatively warm waters of the lake, air rises due to convection which creates clouds and heavy showers. In cold conditions, the moisture in the clouds will fall as heavy snow.

As Buffalo as it the eastern tip of Lake Erie it has been particularly susceptible to this effect during the recent weather.

While we don’t have any lakes big enough for this effect in the UK, we can occasionally see a similar scenario when we get easterly winds in the winter.

Cold air from the continent can be warmed by the relatively warm North Sea as it moves across the water, bringing snow showers to eastern parts of the UK. However, there’s no sign of this in the immediate future for the UK.

Will the US weather affect the UK?

Many people believe that there’s a rule of thumb that weather in the US will arrive in the UK a few days later – but that’s by no means always the case.

In this instance, there’s high confidence that the cold snowy weather will stay on the western side of the Atlantic.

Also, in past winters similar weather situations in the US have strengthened the jet stream and increased the risk of storms across our shores. Again, in this instance, this isn’t expected at the moment.

What we do expect to see is further changeable weather over the coming few days.








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