Wet and dull July

31 07 2015

July 2015 was cool, dull and wet across the UK according to provisional Met Office statistics for 1-29 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.

MeanTemp JulyJuly Rainfall

 

minimum temperature mean temperature sunshine duration precipitation
Jul 1 – 29 2015 Act (°C)   Diff from avg (°C)   Act (°C) Diff from avg (°C) Act (hrs) % of avg Act (mm) % of avg
UK 10.4 -0.5 14.5 -0.6 151.3 88 104.5 134
England 11.4 -0.3 16.0 -0.3 174.8 90 80.0 128
Wales 11.0 -0.1 14.6 -0.6 159.2 89 110.4 119
Scotland 8.7 -0.9 12.3 -0.9 117.2 83 142.5 143
N Ireland 9.6 -1.1 13.4 -1.3 112.0 80 110.9 137

 

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. Clearly these are early month figures and the statistics at the end of the month will change somewhat.





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.





Met Office Forecasting Experiment

27 07 2015

Forecasting the weather accurately relies on a combination of cutting edge forecasting models developed by our research scientists and the skill of interpreting these models by expert meteorologists.

We’ve recently completed a “Forecasting Experiment” which brought together our research and operational expertise for two weeks.

The aim of this was to intensively evaluate and develop our current and experimental models, forecasting techniques, new scientific products and the interaction between them. The overall aim was to evaluate our forecasting capability so we can identify ways to continue improving the way we do things.

Experts from a range of backgrounds analyse model output in the 'Forecast Experiment'

Experts from a range of backgrounds analyse model output in the ‘Forecast Experiment’

We have a number of computer models which can represent weather processes which occur on ever smaller scales.

These models cover different areas of the globe: from the entire world, down to a model which is confined to the UK area and even an experimental model which looks at the weather over an area the size of a large city.

All these models are incredibly complex and have strengths and weaknesses which can be difficult to determine.

By bringing together specialists with considerably different skills and experience in the Forecasting Experiment, it is easier to identify characteristics of the models. This can then inform better interpretation of all the information available to forecasters and can also help with planning improvements in future generations of the models.

The Forecasting Experiment this year was focused on summer weather over the UK. The experiment ran over the end of June and beginning of July.

The first week was characterised by a succession of weather fronts moving eastwards from the North Atlantic over the UK. The second week was dominated by very warm air from Spain moving north across the UK and bringing the hottest July day on record (36.7 °C at Heathrow) with severe thunderstorms to much of the UK, especially the North of England and Scotland.

This mixture of weather types allowed researchers to test models and techniques under a whole range of summer conditions, including high impact weather.

Adrian Semple,who led the experiment, said: “Not only did this experiment promote an exchange of skills, knowledge and experience between the participants, but it also provided a unique environment in which we could critically assess the way in which we produce our forecasts. The experiment will therefore have immediate effects as skills and knowledge are shared and spread throughout the Met Office, but the results can also be used to influence our longer term scientific research and improve future forecasting models.





Has 2015 really been that windy?

24 07 2015

We’ve recently had several questions from the public asking whether this year has been particularly windy compared to others and if there’s any explanation for this. There’s lots of ways at looking at these questions, but the quick answer from our National Climate Information Centre is that – yes, it has been windy this year and a lack of high pressure seems to be to blame. Here Mike Kendon, climate information scientist at the Met Office, takes a detailed look at the questions.

How many calm days?

One way of looking at this is to consider how many days there have been which have not been windy – i.e. calm days – and how this compares with the historical record. The bar chart below counts the number of days each year, for the UK overall, where at least 20 weather stations have recorded a maximum gust speed of 10 Knots (11 mph) or less. This is equivalent to, at most, a gentle breeze, while 20 stations would indicate such conditions fairly widespread for at least 24 hours.

2015 thus far has seen only 8 such days; this being the fewest number of calm days across the UK for at least 20 years – but bearing in mind this covers less than 7 of 12 months of the year so far. However, more notably none of these days have fallen in May, June or July so far.

Chart showing the number of days per year where at least 20 UK weather stations have recorded a maximum gust speed <= 10 Kt (11 mph). 2015 data up to 22 July.

Chart showing the number of days per year where at least 20 UK weather stations have recorded a maximum gust speed <= 10 Kt (11 mph). 2015 data up to 22 July.

Pressure patterns

Calm days are typically associated with areas of high pressure, which normally bring dry, settled conditions during summer and cold, frosty conditions in winter – but common to both seasons often light winds. Areas of high pressure tend to block the prevailing westerly airflow across the UK. However, the variability of our climate means that some years see more days of high pressure, others see fewer such days.

The first map below shows the mean sea level pressure relative to average across the North Atlantic for the period January to June 2015. Over this 6-month period the pressure has been lower than normal to the north of Scotland but higher than normal to the south-west, resulting in a predominant westerly airflow over the UK, meaning that our weather has often been windy. Although during 2015 there have been some periods of high pressure, for example during March and early April, they have been relatively infrequent, particularly from May onwards. The pressure difference shown on the map between Iceland and the Azores is known as the North Atlantic Oscillation (NAO) index.

Pressure anomaly (difference from 1981-2010 average) in mb for the period January to June 2015 and January to June 2011, based on NCEP / NCAR Reanalysis data. Image provided by the NOAA/ESRL Physical Sciences Division.

Pressure anomaly (difference from 1981-2010 average) in mb for the period January to June 2015 and January to June 2011, based on NCEP / NCAR Reanalysis data. Image provided by the NOAA/ESRL Physical Sciences Division.

Rainfall patterns

A westerly airflow across the UK is generally associated with low-pressure systems from the Atlantic bringing windy conditions and rain-bearing fronts. Since this is the UK’s prevailing wind direction, the north-west is, on average, much wetter than the south-east, being most exposed to this direction. In addition, rainfall here is further increased due to the effect of hills and mountains.

During 2015, the persistent westerly airflow has resulted in this north-west / south-east contrast in rainfall patterns being exaggerated. For example, Achnagart, a weather station in the West Highlands of Scotland recorded 2082mm of rain in the period from 1st January to 22 July 2015, compared to 237mm for the same period at St James’s Park, Central London – 9 times as much.

The map below shows rainfall totals compared to average from January to June 2015. So, this rainfall pattern is consistent with this westerly weather type, absence of prolonged spells of high pressure, and relatively windy nature of 2015 so far.

Rainfall January to June 2015 as % of 1981-2010 average for that period.

Rainfall January to June 2015 as % of 1981-2010 average for that period.





A wet getaway

24 07 2015

As many of us plan to head off on holiday, heavy rain and strengthening winds cross southern England today (Friday), persisting overnight in the east, before clearing on Saturday morning.

A Yellow warning has been issued for southeast England and East Anglia, valid from Friday afternoon to 11am Saturday because of the potential impacts the heavy rain and wind could have.

 

Weather warning 24.07.15

As an area of low pressure is crossing northeastwards across the UK today (Friday), close to southern England, it deepens into quite an intense feature for this time of year and is expected to bring disruptive rain and wind, particularly within the warning area.

More than 30 mm of rain is expected quite widely, but there is a chance some isolated locations could well see more than 70 mm of rain. Wind gusts are also expected to be strong across the warning area, with northerly winds gusting to 45 mph inland and around 55 mph along coasts. This combination of factors could bring the risk of disruption to outdoor activities and heavy holiday traffic.
Highways England has launched a website especially for drivers heading to the South West of England to help plan their journey.





A summer forecasting challenge for Friday

22 07 2015

Forecasting rainfall for the UK during the summer has always posed a more difficult challenge than other times of year – and the weather for this Friday is a perfect example.

The various computer models the Met Office uses to forecast the weather differ on how a low pressure system forming to the west of the UK will behave.

We know that it will bring some wind and rain to the southern half of the UK, but there is no consensus on exactly which track it will take across the country and precisely when it will arrive.

Below you can see the area most likely to see some persistent rain during Friday and into Saturday. There is a 30% chance that rainfall could extend further north than this. The system is likely to bring up to 15-25 mm of rain and winds of up to 30 mph, mainly in exposed areas.

Forecast uncertainties 24-25-July

Currently there are no plans to issue a weather warning for this event, but clearly it has the potential to affect people’s plans for Friday now summer holidays are in full swing.  You can hear more about Friday’s forecast in the video below.

We’ll be keeping a close eye on the situation as it develops to ensure everyone has the clearest picture of what’s likely for Friday, so it’s worth staying up to date with the forecast over the next couple of days.

The current situation is a good example of why summer is tricky because at this time of year the details are vitally important.

Will the showers be inland or at the coast, when will low cloud clear to let warm sunshine through? In winter this might not be so important, but in summer when many are outside making the most of all the UK has to offer it can make a huge difference to your day.

Familiar features of our landscape such as hills, valleys or the sea can cause subtle variations in heat and moisture and therefore dominate the local weather outcome.  This can result in big differences in the weather in quite small areas, it can be sunny on the beach but raining inland or a village fair could be rained off while the next village down the road is dry.

At this time of year it’s always a good idea to keep a close eye on the forecast as the situation can change from day to day.

We’re always harnessing new science and technology to make forecasting ever more accurate and summer forecasting is a major focus for future gains.





Met Office Science Camps a huge success

20 07 2015

Over 200 secondary school pupils have taken part in four Met Office Science Camps this year.

The overnight camps, held at Met Office HQ in Exeter, provided a unique opportunity for 11-13 year old to join in a selection of hands-on activities led by Met Office staff. The activities covered a wide range of topics and helped explain how we measure and forecast the weather and climate.

Science Camp May 2015

Twelve schools and three scouts/guide groups took part in the events and Director of Science at the Met Office, Andy Brown said: “As well as being fun, Met Office Science Camps engage, challenge and enthuse students, encouraging them to develop scientific skills and hopefully inspire the scientists of the future.”

As one of the UK’s top science and engineering organisations, the Met Office is continually looking at ways to engage people, young and old, in the fascinating worlds of weather and climate science.

The Met Office Science Camps are part of the Met Office STEM (Science, Technology, Engineering and Math’s) Outreach programme which aims to improve understanding of how weather and climate are measured and forecast. The programme has been awarded the European Meteorological Society Outreach and Communication Award in recognition of our outstanding efforts to engage young people.

Over the last decade or so, predicting the weather and climate has become one of the most important areas of scientific research. Work at the Met Office is incredibly varied, and this is reflected in the variety of career opportunities available, including everything from Science and Forecasting to Engineering and Business Development.

You can hear from a whole range of different people who are employed at the Met Office, from IT specialists to Climate Change scientists, in a series of podcasts.

How to Register

If your school or organisation would like to be added to our mailing list for the 2016 Met Office Science Camps, please email us at science.camp@metoffice.gov.uk with your name and the school (or organisation) that you are emailing on behalf of. We take group bookings from schools or other organisations, rather than individual campers. If you are a parent or student looking to get involved then please get in touch with a teacher at your school and ask them to contact us.

If you have any queries, please email us: science.camp@metoffice.gov.uk.





Early July sees big rainfall contrasts

20 07 2015

After a hot and humid start to the month, when record daily maximum temperatures were recorded at several stations across the country on 1 July, it has been a fairly average month so far for the UK as a whole. However, on a regional scale there are some contrasts.

Using figures up to 15 July, mean temperatures have been close to or above average, with counties in eastern and southeastern England highest relative to average.

Meanwhile, for rainfall there are more notable variations, with eastern parts of England having received around or less than half the amount of rainfall that would be expected by mid-month. For example, Surrey and Sussex have both recorded less than 20% of the month’s average rainfall with 7.8mm and 9.9mm respectively. By the 15th of the month you would normally expect around 48% of the whole-month average.

This is in comparison with parts of Eastern Scotland where some places have already recorded more rainfall than the whole-July average. Aberdeenshire and Kincardineshire have already seen rainfall in excess of July’s average at 79mm and 106.6mm.

After the hot, sunny start to the month there have been periods of unsettled weather, with weather systems arriving from the Atlantic bringing rain or showers at times. This has been interspersed with drier, sunny spells.

With west or southwesterly winds dominating, there have been some rather cloudy days in the south, leading to mild nights.

The table below shows figures for the 1-15 July. You would normally expect about 48% of the full-month average for sunshine and rainfall at this point in the month.

Mean temperature Sunshine duration Rainfall
1-15 July
Act (°C) Diff from avg (°C) Act (hrs) % of avg Act (mm) % of avg
UK 15.5 0.4 88.0 51 46.9 60
England 17.0 0.7 103.7 54 30.5 49
Wales 15.4 0.2 89.2 50 56.4 61
Scotland 13.3 0.0 66.8 47 71.9 72
N Ireland 14.2 -0.4 57.7 41 45.9 57

 





Annual State of the Climate Report for 2014 published

16 07 2015

A report which looks at all the climate variables that can be measured for 2014 has been released today.

The annual ‘State of the Climate’ report has been published by the American Meteorological Society, presenting summaries for all so-called Essential Climate Variables (ECVs).

These include various types of greenhouse gases, temperatures throughout the atmosphere, ocean, and land, water cycle variables, ocean variables such as sea level and salinity, sea ice extent, permafrost temperatures and others. The majority of these reflect a planet that is continuing to warm.

The exceptional warmth of 2014 occurred against a backdrop of neutral to marginal El Niño conditions. Europe was especially warm and all land regions apart from North America showed above average frequency of warm extremes.

Annual average anomalies (difference to normal) for 2014 for surface temperature from the Met Office’s global temperature dataset, HadCRUT4 relative to a 1981-2010 climatology period.

Annual average anomalies (difference to normal) for 2014 for surface temperature from the Met Office’s global temperature dataset, HadCRUT4 relative to a 1981-2010 climatology period.

Over oceans, global sea surface temperatures and ocean heat content were also observed to be exceptionally warm and sea level exceptionally high.

The significant warmth is reflected strongly in regions of snow and ice. Arctic sea ice was well below average but above the exceptional lows seen in 2007, 2011 and 2012. Glacier volume is declining year on year – preliminary results for 2014 make it the 31st consecutive year of decline.

Long-lived greenhouse gases continued to increase, primarily owing to rising carbon dioxide (CO2) concentrations, in addition to methane (CH4), nitrous oxide (N2O) and other minor trace gases.

The Met Office’s Kate Willett, a lead chapter editor on the new report, said: “The comprehensive view of the different variables in the report enables a better understanding of the interconnectedness of our climate system.”

‘State of the Climate in 2014’ is the 25th consecutive instalment of the report, which is lead by scientists from NOAA’s National Centers for Environmental Information, along with 413 scientists from 58 countries.

Met Office scientist Kate Willett leads the Global Climate chapter and several other Met Office scientists contribute, using Met Office Hadley Centre climate data. All reports are freely available online.








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