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.




Wet and dull July

31 07 2015

UPDATE: The figures below have now been updated to include data from the 1-31 July 2015.


July 2015 was cool, dull and wet across the UK according to Met Office statistics for 1-31 July.

The month began with a record-breaking heatwave, with hot, humid air moving in from the continent.  36.7 °C was recorded at Heathrow 1 July, the highest recorded temperature in the UK since August 2003.

However the rest of the month has been characterized by cooler and often more unsettled conditions, particularly in the north, as a result of a westerly Atlantic air flow.  Rainfall has been above average in most areas, particularly across parts of East Anglia, central and eastern Scotland.

MeantempJuly2015 RainfallJuly2015

minimum temperature mean temperature sunshine duration precipitation
Jul 1 – 31 2015 Act (°C)   Diff from avg (°C)   Act (°C) Diff from avg (°C) Act (hrs) % of avg Act (mm) % of avg
UK 10.3 -0.6 14.4 -0.7 164.8 96 109.5 140
England 11.2 -0.4 15.8 -0.5 191.9 99   82.3 131
Wales 10.8 -0.3 14.4 -0.8 175.1 98 112.4 121
Scotland 8.7 -0.9 12.2 -1.0 125.3 89 152.4 153
N Ireland 9.6 -1.1 13.3 -1.3 117.4 84 116.8 144

The south-east has seen some drier and more settled weather with temperatures near average, although there has also been some changeable weather here with over 20mm of rain falling on the 24 July and some cooler temperatures and strong winds on 26 and 27 July.

Elsewhere temperatures have been below average, particularly in the west and north, and it has been a rather dull month with sunshine totals being below average across much of the country.

Data from the Met Office’s UK digitised records dating back to 1910. You can explore our climate data on our website.





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.





Are we set for record July rainfall?

27 07 2015

While July has seen a good deal of dry and bright weather, we’ve also seen a few periods of heavy rainfall.

Whether through intense thundery downpours or prolonged periods of rain such as seen in southern parts of the UK on Friday last week, these events have dramatically pushed up the rainfall totals for the month.

This has led to speculation about whether this July could be on course to be the wettest on record. However, a quick look at the statistics shows that while it has certainly been wet, we’re unlikely to break any national records this month.

Provisional rainfall statistics for July 2015 so far suggest that with 5 days of the month remaining much of the country has already received close to or above average rainfall for the month – but we’re some way off breaking the records for each country.

Table showing rainfall figures so far this month compared to average and the records:

Rainfall 1-26 Jul 2015 Current record July 1981 – 2010 average
UK 93 mm 146 mm (2009) 78 mm
England 70 mm 129 mm (2009) 63 mm
Scotland 128 mm 186 mm (1940) 100 mm
Wales 102 mm 241 mm (1939) 93 mm
Northern Ireland 95 mm 186 mm (1936) 81 mm

The wettest regions compared to average have so far this month been eastern Scotland, East Anglia and the south west of England. If records are going to be broken they will most likely be localised rather than national records.

Even those regional records are far from a sure thing. The weather is generally improving for most parts of the country and high pressure, bringing more settled conditions, is expected to build towards the back end of the week.

This means the last few days of this month are unlikely to add big rainfall numbers to the totals we have so far.

Map showing 1-26 July 2015 rainfall compared to the 1981-2010 average. Most places have received their full-month average (shown in white), while the darker blue areas have seen significantly more than average already.

Map showing 1-26 July 2015 rainfall compared to the 1981-2010 average. Most places have received their full-month average (shown in white), while the darker blue areas have seen significantly more than average already.





Record May temperatures for Spain

14 05 2015

Update: On Thursday, records were broken once again across southeast Spain. Valencia equalled Lanzarote Airport’s 42.6C from the previous day. Other stations in the Valenciana region exceeded this value, with Xativa and Carcaixent reaching 42.7C and 42.9C respectively; however these are as yet unconfirmed so are not official. Either way, not only is this 42.6C a new Spanish record for May, but a European-wide May record.  

Meanwhile, the heat is spreading to other parts of Europe, with extreme warmth expected today along the north coast of Sicily and parts of mainland southern Italy.

A new record maximum temperature for Spain was set yesterday, with many local records also broken, and the heat continues today in the southeast.

Iberia Temps

The new record of 42.6C was recorded at Lanzarote Airport in the Canary Islands, beating the previous May record for Spain by a relatively large 2.5 degrees. It also beats the Lanzarote station’s own previous highest May temperature by a whopping 6 degrees.

The previous May record in Spain was 40.1C at Cordoba on the mainland, and Cordoba itself recorded a new May station record on Wednesday with 41.2C.

Met Office Global Model mean sea level pressure and temperature

Met Office Global Model mean sea level pressure and temperature

Further records could be broken today in parts of Andalucía, Mercia and Valenciana as air continues to feed in from North Africa. However, a cold front is pushing gradually southeastwards across Spain, bringing cooler air across much of the country by the end of the week.





Possible record heat in Spain, while heavy rain and snow affect the Alps

13 05 2015

Parts of Spain, Portugal and southern France are experiencing unusually high temperatures at the moment. On Tuesday, Seville recorded 38C, and today will be another very hot day for the time of year, with temperatures widely expected to reach the low to mid 30s Celsius.

Met Office Global Model mean sea level pressure and temperature

Met Office Global Model mean sea level pressure and temperature

The hottest conditions will be across the Andalucía region of southern Spain. If temperatures reach or exceed 40C in Seville today this will be a new May record. Cooler conditions will gradually spread from the north tomorrow, although another very hot day is likely in southern Spain. Temperatures are then expected to return closer to average in all regions by Friday.

Meanwhile, southern Germany, Switzerland, Austria, and northern Italy are at risk of heavy rainfall over the coming days, with heavy snow possible on Friday across the Alps. Up to 150mm of rain could fall within 48 hours, possibly leading to flash flooding and landslides in this mountainous region of Europe, as well as increasing the avalanche risk due to fresh snowfall.

Whilst neither of these two weather events in Europe will affect the UK, we are expecting some heavy rain of our own on Thursday. The band of rain will move across southwest England during the early hours and edge slowly northeastwards through the day, but become almost stationary across parts of Wales, central-southern and southeast England. However, northern England, Northern Ireland and Scotland will remain largely dry and fine.





More warm weather this week – but what’s in store for the summer?

13 04 2015

This week is set to see some unseasonably warm weather for parts of the UK – with temperatures expected to climb to the low to mid-20s Celsius in the south on Tuesday and Wednesday.

Warm air flowing up from the south west will combine with high pressure, bringing settled conditions and sunny spells for many.

Warmest days of the year so far

This week’s above average temperatures follow on from a similar spell last week, which saw temperatures top out at 21.9C at St James’s Park in London on Friday.

This was the ‘warmest day of the year so far’, but It looks like Tuesday and Wednesday will top that – which is to be expected as we head through spring and edge closer to the start of summer.

Unfortunately, the weather we get in April doesn’t necessarily tell us anything about the kind of summer we can expect. We’re still in the midst of spring, so it’s far too early to say what the months of June, July and August may hold.

Summer ‘heatwave’ speculation

That hasn’t stopped speculation about heatwaves, the warmest summer ever and record temperatures in the media. Some stories cite our three month outlook for contingency planners as proof of the impending heatwave, but this is in no way an accurate reflection of what it shows.

The outlook shows probabilities attached to different scenarios for temperature and rainfall over the whole three-month period it covers. This is useful for those who use probabilities to plan ahead on longer-timescales, but not very useful for deciding where and when to go on your UK summer holiday, for example.

What does the longer outlook show?

Our current three month outlook does show that above average temperatures are more likely than below average temperatures for the April-June period. The outlook is essentially the scientific equivalent of factoring the odds on a horse race and, just like a horse race, the favourite doesn’t always win.

It’s also important to note that above average temperatures over a three-month period could come about in a variety of ways in terms of actual weather – we can still see warmer than average temperatures when it’s cloudy and wet, for example. Also, even in an above average three-months not all individual months would need to be above average.

This just reinforces the point that the contingency planners outlook doesn’t tell us what specific weather we are going to see at a specific location. For the best information on the weather ahead, people should use the Met Office’s 5-day weather forecast supplemented with our 30-day outlook.

By keeping up to date with the latest forecast, you’ll always have the most up-to-date and accurate view of the weather in store for the UK.





Powerful super-typhoon heads for Philippines

1 04 2015

There is currently a super typhoon in the western North Pacific called Maysak. This is a particularly strong storm for the time of year with winds in excess of 160 mph. The strongest storms in this region usually occur between August and October. Tropical storms, including typhoons, are reliant on sea surface temperatures for their energy, and as the northern hemisphere has just moved from winter to spring, this is the coldest time of year for sea temperatures. However, in the region where Typhoon Maysak formed just north of the equator, sea temperatures are almost always above 26°C, which is the critical value for tropical storm formation. Furthermore, the sea temperatures are unusually warm in this area by more than 2°C.

Super Typhoon Maysak is the fourth tropical storm of the season in the western North Pacific, the others being Mekkhala, Higos and Bavi. There has not been a year with four or more tropical storms in this region forming before the end of March since 1965. Three of the four storms have been typhoons – only Bavi remained below the 74mph threshold (the sustained wind speed required to become a typhoon). There have never been as many typhoons before the end of March in the era of reliable records (since World War II). Maysak was also the strongest typhoon to develop in March in this region since Mitag in 2002.

Typhoon Maysak as seen from the MTSAT satellite on 1 April 2015 Image courtesy of digital-typhoon.org

Typhoon Maysak as seen from the MTSAT satellite on 1 April 2015
Image courtesy of digital-typhoon.org

Maysak has now started to weaken as it moves west-northwest towards the Philippines. However, Maysak is still likely to be a typhoon when it makes landfall this weekend. There is still some uncertainty over the exact track of the storm, but the most probable path suggests the Philippines’ northern island, Luzon, is most at risk – including the capital Manila. Wind damage and flooding are likely, particularly in coastal areas.

Typhoon Maysak on 1 April 2015. Image courtesy of the US Naval Research Laboratory

Typhoon Maysak on 1 April 2015.
Image courtesy of the US Naval Research Laboratory

The Eye of the Storm

Air sinks at the centre of a typhoon, resulting in the formation of an ‘eye’ which is sometimes free of cloud and mostly calm. However, on occasions small scale rotations can develop within the eye causing distinctive ‘mesovortices’ (small scale columns of rotating air) in the low level cloud pattern. These can be seen in this satellite loop of Typhoon Maysak created by the Cooperative Institute for Meteorological Satellite Studies at the University of Wisconsin:

http://cimss.ssec.wisc.edu/goes/blog/wp-content/uploads/2015/03/MAYSAK_H8VIS_064_31March_end0600_fast.gif

The Met Office works closely with counterparts at the Philippines weather service PAGASA, providing the latest information on computer model predictions of the likely track and intensity of Typhoon Maysak as it nears the country.

Official warnings of west Pacific tropical storms are produced by the Japan Meteorological Agency. The Met Office routinely supplies predictions of cyclone tracks from its global forecast model to regional meteorological centres worldwide, which are used along with guidance from other models in the production of forecasts and guidance.

Met Office StormTracker provides a mapped picture of tropical cyclones around the globe, with access to track history and six-day forecast tracks for current tropical cyclones from the Met Office global forecast model, as well as the latest observed cloud cover and sea surface temperature. We also provide updates on current tropical storms via @metofficestorms on Twitter.





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.

rainfall

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.








Follow

Get every new post delivered to your Inbox.

Join 7,277 other followers

%d bloggers like this: