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

 





On the record – observing a ‘heatwave’

7 07 2015

Last week on 1 July the UK saw its warmest July daily max temperature on record (records date back as far as 1853), with 36.7 °C at Heathrow. This has led to considerable interest in the wider context of the record temperatures. Here, Mark McCarthy, Manager of the Met Office National Climate Information Centre discusses records and how we record them.

Where were record temperatures observed on 1 July 2015?

Although Heathrow measured the highest temperature recorded by the Met Office observing network on a July day, record temperatures were reported across a wide stretch of the country, including from some of the Met Office’s very long running climate stations.

Temperatures exceeded 35 °C at a handful of locations in London and the south east, but also reached the low 30s across the Midlands, East Anglia and parts of north-west and north-east England. It is in these areas that July temperature records were broken.

Map showing stations recording new July temperature records, 1 July 2015

Map showing stations recording new July temperature records, 1 July 2015

The table below lists those stations with more than 50 years of observations for which 1 July 2015 was a record. These data show that record temperatures for July were not confined to London or other major urban centres. The records were, in fact, part of a larger scale pattern of high temperatures extending through Spain, Portugal and France.

SITE DATE OF PREV JULY RECORD PREV RECORD JULY MAX (°C) 1 JULY 2015 MAX (°C) YEARS OF DATA
Durham 31/7/1943, 10/7/1921 30.6 31 133
Sheffield 31/7/1943, 10/7/1921 31.7 33.3 130
Bradford 31/7/1943, 13/7/1935 30.6 30.9 106
Cranwell 22/7/1996 32.6 34.3 93
Sutton Bonnington 19/7/2006 32.9 33.6 84
Stonyhurst 3/7/1976 31.1 32.6 75
Manston 15/7/1983 31.4 33.6 74
Goudhurst 3/7/1976 32.8 33.3 74
Waddington 12/7/1949 32.2 33.1 67
Heathrow 19/7/2006 35.5 36.7 66
Nottingham (Watnall) 3/7/1976 32.3 33.9 64
Marham 3/7/1976, 5/7/1959 32.8 33.5 58
Wittering 5/7/1959 32.8 35.3 53
St James’s Park 5/7/1959 34.4 34.7 52

How does this compare to past heatwaves?

Temperatures over 36 °C reported at any station in the UK observing network are very rare, with only a handful of notable heatwaves seeing such extremes. The heatwaves of August 1990, August 2003, and July 2006 each saw a number of stations exceed 36 °C, whereas on 1 July 2015 Heathrow was the only station.

The Met Office maintains a list of climate extremes for the UK. It is standard practice to report the highest and lowest temperature every month as part of our routine monitoring of UK weather and climate. It is therefore always noteworthy when one of these records is broken.

While there is no doubt that some previous heatwaves have seen more extreme or more widespread high temperatures overall – particularly in the climatologically warmer period from late July into early August – 1 July 2015 has the honour of holding the highest recorded temperature for a July day with 36.7 °C at Heathrow.

How do you ensure the data are reliable?

To ensure consistency, Met Office weather records are only given for stations with standard instruments and exposure. This means that our records would not represent the extremes that may have occurred in places where we do not have standard instruments. This may have been the case on 1 July 2015, where the availability of additional data from amateur observers contributing to Met Office WOW show peak temperatures in the range 35 to 37 °C to the west London.

It is reasonable to ask whether Heathrow, as a major international airport, can provide a reliable climatological record. Are the observations biased by the presence of runways and air traffic?

The instrumentation and station enclosure are managed so that they meet the standards required by the Met Office and set out by the World Meteorological Organization. The site has been operating for 66 years and provides an excellent long observational series for west London.

The first thing we can do is compare the climatological temperatures with a nearby station at Kew Gardens. The average daytime maximum temperatures for the two sites are very close:

Site June July August
Heathrow 21.04 °C 23.54 °C 23.15 °C
Kew 21.02 °C 23.48 °C 23.15 °C

On 1 July the maximum temperature recorded at Heathrow (36.7 °C) was higher than Kew (35.7 °C). Modern instrumentation means we can look at the temperatures minute-by-minute at the two sites, as shown below. The two locations recorded very similar temperatures through most of the afternoon and the average temperature at the two sites between 12:00 and 18:00 GMT agree to within 0.02 °C. However, there was a peak in temperature at Heathrow between 14:00 and 14:30 GMT that was not seen at Kew Gardens. What could cause such a peak?

Temperature (°C) graph for Heathrow and Kew Gardens 1 July 2015

There were scattered clouds in the area that afternoon. Both Heathrow and Kew Gardens have instruments measuring solar radiation, shown in the graph below. Both sites recorded a general dip in solar radiation due to clouds from approximately 13:30 to 15:00 GMT which corresponds to a slight cooling at both sites. Heathrow saw a short gap in the clouds shortly after 14:00 GMT which resulted in a similarly short lived peak in temperature, while Kew Gardens remained cloudy. In turn Kew Gardens then saw a brief spell being sunnier than Heathrow just before 15:00 GMT and became warmer than Heathrow for about an hour.

Solar radiation (W/m2) graph for Heathrow and Kew Gardens 1 July 2015





Ten Tors

8 05 2015

This weekend sees the 2015 Ten Tors challenge and once again, the Met Office will be providing tailored forecasts for the organisers to help with event planning and coordination. This year, for the first time, an Operational Meteorologist will also be at Okehampton Camp for the weekend, providing the latest information on weather conditions across Dartmoor throughout the event to help the organisers make the necessary decisions to keep the teams safe.

Forecast

Chief forecaster Dan Suri said “The event may start on rather a wet note, with some heavy showers likely on Saturday morning”. These showers will clear later in the morning leaving a drier and brighter afternoon. It will be breezy too, making it feel quite chilly in the wind. Saturday night will be largely dry, but it is likely to become murky through the early hours of Sunday, with occasional drizzle and hill fog. The cloud base will probably lift a little during Sunday morning, but higher parts of the Moor are likely to stay murky, and whilst the odd brighter spell may develop with shelter from the wind, it will remain largely cloudy. Still quite breezy on Sunday too.

The challenge

The weather plays a major part in the successful completion of the event for everyone taking part. Around 400 teams of six take part in the challenge to complete the course. There are three different course lengths, depending on the age and ability of the team:

  • 35 miles
  • 45 miles
  • 55 miles.

The idea of the challenge is for the teenagers to become self-sufficient for the weekend – carrying everything they’ll need for the trek and making their own decisions.

At this time of year, conditions can be varied, from torrential rain to hot sunshine.

Ten_Tors_infographic_2015

For more information about the event, including the latest weather and a video explaining the variety of conditions you might expect on Dartmoor, take a look at our events pages.

Our National Park forecast service includes forecasts for a wide range of locations on Dartmoor, many of which are included within the Ten Tors event. You can also find forecast information on our weather pages.





Sunny and dry April

30 04 2015

UPDATE: YOU CAN SEE AN UPDATED STORY ON APRIL’S WEATHER ON OUR WEBSITE.

The early April figures (1st – 28th April) show it was a sunny and warm month over all, with well above average sunshine almost everywhere. At the moment it ranks as the fifth sunniest April across the UK as a whole. Some locations, particularly in the East of the country, have so far seen almost 50% more sunshine than average.  East Scotland has had its sunniest April on record, beating 1942’s 200 hours of sunshine by 2 hours and it was the second sunniest for England East and NE with 212.4 – just behind 2011 with 216.9 5 hours.

April Sunshine Anomaly 1981-2010

April Sunshine Anomaly 1981-2010

Mean temperatures for the month have been also mostly above average. The mean temperature for the UK was 8.0 C, which is 0.6C above the long-term (1981-2010) average for the whole month. Daytime temperatures rose above average in many areas, especially in the south, with the year’s highest temperature so far (25.6 °C) recorded at Faversham (Kent) on the afternoon of the 15th. This is the highest April temperature anywhere in the UK since 2011.

However, in contrast, under often clear skies, minimum temperatures have been near or below average, particularly in Northern Ireland and parts of northern England and southern Scotland. Katesbridge (County Down) recorded -8.0 °C on 27th April.

Mean Temperature Sunshine hours Rainfall  
 April 2015
Actual Diff to Avg Actual % of Avg Actual % of Avg
  degC degC hours % mm %
UK 8.0 0.6 199.2 135 41.6 57
England 8.9 0.8 209.1 135 23.3 40
Wales 8.5 0.9 203.3 132 32.4 36
Scotland 6.4 0.3 183.0 136 72.2 79
N Ireland 7.7 0.1 193.2 132 52.8 70

April has been a dry month, particularly across the southern half of the UK with only a third, to a half, of normal rainfall quite widely and less than 20% in some places.

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.





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.

 





Cool, wet August ends fairly average summer

29 08 2014

After a dry and warm start, summer 2014 is set to end on a rather average note – with temperatures and rainfall close to normal levels for the season.

Using figures up to 27 August and then assuming average conditions for the final few days of the month, Met Office statistics show the UK mean temperature for this summer will be around 14.8C. This is just 0.5C above the long term average (1981-2010).

Rainfall overall is close to average, with the UK having seen 246.7mm of rain – which is just over the long-term average of 241.0mm. Rainfall from the final few days of August will add to this number, so overall the summer will be slightly wetter than average.

As ever when looking over a whole season, the statistics mask some big variations between each month.

June and July were both characterised by drier and warmer than average conditions across the UK which meant the summer was already one of the best we’ve seen in recent years.

UK rainfall as a percentage of the long-term (1981-2010) average

Map showing August UK rainfall as a percentage of the long-term (1981-2010) average for the month

August bucked that trend, however, with cooler and wetter than average weather. Taken together, this has led to the fairly average final statistics for summer.

Looking specifically at the early August figures, also released today, the UK mean temperature up to the 27th of the month is 13.8C which is 1.1C below the long-term average. This ranks it as currently the coolest August since 1993, but that could change when the final few days of the month are added.

August is also the first month since November 2013 to have been cooler than average, breaking an eight month run.

In terms of rainfall, August has been much wetter than average, with 127.1mm of rain which is 142% of the long-term average (89.5mm). This makes it the 18th wettest August in the records, but it may climb higher when the figures for the whole month are available.

 

Mean Temperature Rainfall
Summer* Actual (°C)
Diff from Avg Actual (mm)
% of Avg
UK 14.8 0.5 258.2 107
England 15.9 0.4 211.6 109
Wales 14.8 0.3 257.5 90
Scotland 13.1 0.6 338.4 111
N Ireland 14.3 0.4 244.6 96

*Please note these are projected numbers that include statistics from 1 June to 27 August, then assume average conditions for the final few days of the season. They may not accurately represent the final full-season figures.

 

Mean Temperature Sunshine hours Rainfall
August** Actual (°C)
Diff from Avg Actual (hours)
% of Avg Actual (mm)
% of Avg
UK 13.8 -1.1 154.2 95 127.1 142
England 14.9 -1.2 169.7 93 103.4 149
Wales 13.9 -1.0 152.3 91 128.2 119
Scotland 11.9 -1.1 132.4 99 169.0 145
N Ireland 13.3 -1.0 134.2 99 112.8 116

** Please note these are preliminary statistics from 1-27 August. The final figures will change once statistics from the final few days of the month are included.





A wet start to August

15 08 2014

The UK has already seen nearly its entire ‘normal’ rainfall for August in the first half of the month.

Figures up to the 13th of August show there has been 86.1mm of rain so far in the UK, just short of the 89.5mm long-term (1981-2010) average.

Looking at individual countries, Scotland has already seen more than its full-month average with 121.4mm of rain so far compared to the average of 116.7mm. The Inverness and Moray areas have been particularly wet, with significant flooding from ex-hurricane Bertha on 10 to 11 August.

Rainfall for England and Northern Ireland so far is just under the full-month average, while Wales has been the driest relatively speaking – with 83.2mm of rain making up 77% of its full-month average. Normally at this stage you would expect about 42% of the average to have fallen.

With regards to temperatures and sunshine, the month has been much closer to average so far.

The UK mean temperature is currently 15.2C, which is 0.3C above the full-month average.

UK sunshine hours are at 77.8 hours, which is 48% of the full-month average – so just ahead of where we’d expect after 13 days of the month.

While these figures are interesting, they don’t tell us where the month will end up overall – we’ll have to wait until the full-month figures are in before deciding where this August fits in to the records.

As we head in to next week there should be a good deal of drier weather but with northerly winds bringing in cooler air it will feel colder than of late, especially at night.

This will feel noticeably cool in the wind, so people heading out in the evening may want to take a few extra layers.

Mean temperature Sunshine Rainfall
1 – 13 August 2014 Actual

Diff from 81-10 average

Actual % of 81-10 average Actual % of 81-10 average
Celsius Celsius hours % mm %
UK 15.2 0.3 77.8 48 86.1 96
England 16.5 0.4 91.8 50 64.7 93
Wales 15.3 0.3 85.1 51 83.2 77
Scotland 13.2 0.2 55.3 41 121.4 104
N Ireland 14.5 0.2 61.9 46 92.7 95




Guest blog: RNLI lifeguards warn of beach dangers after winter storms

17 04 2014

Brett Shepherd, Lifeguard Manager, provides some timely advice for those planning a trip to the beach as the Easter weekend approaches.

As many of our RNLI lifeguards head back to British beaches this weekend, I’m hoping for some lovely weather to herald the start of the season. But the affect winter storms have had around the coast mean that many of the country’s most popular beaches are looking very different to this time last year.

Unprecedented storms over the winter have changed the make-up of some beaches, with sand dunes in some areas being washed away leaving sheer sand cliffs. On other beaches, access points to and from the beach have changed and shifting sand has left deep channels that in turn create strong rip currents.

Our RNLI lifeguards, who have been patrolling the country’s beaches since 2001, will be keeping visitors safe on 33 beaches across the UK over the Easter bank holiday weekend. Whilst we’re hoping lots of people head out to enjoy our glorious coast, there are a couple of easy safety steps we’re urging people to take following the winter storms.

Firstly, always head to lifeguarded beaches; they are far safer environments and will help offer you peace of mind. You can download a special ‘Beach Finder’ app from our website which will tell you where the nearest lifeguarded beaches are, or check with local authorities. We’d also urge people planning on visiting a beach to check local information in advance, as the beach environment may have changed dramatically since your last visit.

Swimmers should ensure that they swim between the red and yellow flags, which mark out the safest area to swim and are patrolled by lifeguards. Lifeguards are always on hand to offer beach safety information and advice, and please take heed of local safety signage.

By highlighting the dangers before visitors arrive at the beach, we hope that we can avoid potential incidents and everyone can enjoy their time on the beach in safety.

RNLI lifeguard rescue. Copyright Nigel Millar

RNLI lifeguard rescue. Copyright Nigel Millar





2013: Average figures mask some notable highlights

31 12 2013

Provisional statistics for 2013 suggest it has been a very average year – but those annual figures mask a year which features some significant weather highlights.

Using figures up to 29 December and then assuming average conditions for the last two days of the year, statistics for 2013 show temperature, rainfall and sunshine amounts have all been very close to the 1981-2010 average.

The mean temperature for the UK is currently 8.76C, which is just 0.08C below the annual long-term average, rainfall stands at 1079.8 mm, which is about 94% of the average, and sunshine is at 1425.7 hours, which is 104% of the average. All in all, it seems like a very ‘normal’ year.

However, a closer look at individual months and seasons shows a different picture.

The coldest spring for more than 50 years

This year’s spring was the coldest since 1962. Temperatures were well below average in all areas, but particularly England and Wales, and it was the coldest spring in the Central England temperature series since 1891.

The cold season was mainly due to the very cold March (the coldest month of the extended winter) – but April and May also saw well below average temperatures. Winds were often from the east or north, with notably low temperatures and some unseasonably late snowfalls in places extending into April and May.

A fine summer and autumn’s St Jude’s Day storm

However, after a mixed June, July kickstarted a period of relatively fine weather which led to the warmest, driest and sunniest summer since 2006. The season itself isn’t that remarkable in its own right, but becomes so when put into context of the last few years which have generally seen disappointing weather.

Autumn was fairly average in terms of its numbers, with temperature, rainfall and sunshine close to average, but October featured the St Jude’s Day storm. This storm is judged to be ranked within the top 10 most severe storms in the autumn across southern England in the last 40 years, but is not in the same category as the ‘Great Storm’ of October 1987.

A mild but stormy December

After a fairly dry November to finish the autumn, we moved in to what has become a very unsettled and stormy December. The first major storm came through on the 5th and 6th, then another followed on the 18th and 19th, with another storm tracking past the UK on the 23rd and 24th.

While there have been strong winds during December, rainfall has seen marked regional differences. For example, parts of southern England have seen around double the amount of rain they would normally expect while some spots along the east coast of the UK have only seen around half of their December average.

Other than the generally unsettled conditions, this December has also been mild – it is currently ranked as the seventh mildest December in our records dating back to 1910, although this ranking could change when the final figures come in.

You can find a wealth of information about the UK’s weather and climate throughout 2013 on our climate pages.

Some 2013 extremes:

Max temp – 34.1C at Heathrow, London 1 August

Min temp – -13.6C at Buntingford, Hertfordshire 22 January

Max wind gust – 142mph, Aonach Mor, Invernesshire 5 December

 

Keeping the UK informed

It has also been a notable year for the Met Office. Throughout 2013 the Met Office’s forecasts and warnings have provided timely advice during the periods of severe weather we have seen, helping the UK stay prepared and minimise impacts.

Our Get Ready for Winter and Get Ready for Summer campaigns saw many different companies and organisations working with us to help people prepare for the ever-changing UK weather.

We’ve continued to work in partnership with others around the world to develop the understanding of weather and climate science, helping to drive forward accuracy.

A year of achievement for the Met Office

Met Office staff have again received a high level of recognition for their work. In October Dr Nick Dunstone was named Outstanding Young Scientist for Climate Sciences by European Geophysical Union, while Dr Peter Stott was recognised as one of the ‘Global Thinkers’ of 2013 by Foreign Policy magazine.

Very recently, the Met Office’s Chief Executive, John Hirst, and Chief Scientist, Professor Julia Slingo, were recognised in the New Year’s Honours list.

Other Met Office highlights include:

  • The launch of Europe’s Space Weather Prediction Centre helping protect the technologies our day-to-day lives rely on from severe solar flares, space storms and solar wind which can disrupt them.
  • The launch of Climate Service UK marking a step-change in the provision of services to assess how a changing climate might affect business and society.
  • Retaining our position as the leading operational forecaster in the World.
  • The number of weather reports received by our Weather Observation Website passing 100 million.
  • A celebration of the centenary of the pioneer of modern day weather forecasting, Lewis Fry Richardson, taking up his post as Superintendent of Eskdalemuir Observatory.




Jet stream shift to bring summer weather

1 07 2013

It’s usually true to say that confidence in a weather forecast decreases the further out you look.

However, we have a situation at the moment where we are actually more confident in the detail for this weekend and beyond rather than over the next few days.

This is because we are seeing some very strong signals for high pressure to dominate the weather from around Friday and then persist for several days afterwards.

In summer high pressure means fine weather, and it also looks like it will become very warm as well.

Normally we can’t give much detail beyond the 5-day forecast period, but with the current situation we can give a forecast beyond that with a higher than usual level of confidence.

So for, say, the Men’s Wimbledon Final on Sunday it looks like it will be dry and very warm with a good deal of sunshine. We are less confident in predicting who will be in the final, or who will be the winner, though.

As we go through into next week, it looks highly likely that one or two places will nudge towards the 30 C mark.

With this in mind, it’s likely that by the middle of next week we’ll have topped the current warmest temperature of the year, which was 27.2 C recorded at Heathrow yesterday (Sunday, 30 June).

So why will we be seeing high pressure develop over the UK to give us this spell of fine weather?

Well, to get this type of situation we need the jet stream to be in the ‘right’ place for this time of year – tracking to the north of the UK between Iceland and NW Scotland.

Chart showing expected position of the jet stream on 6 July 2013.

Chart showing expected position of the jet stream (shown in shades of green) on 6 July 2013.

In this position it guides rain-bearing Atlantic low pressure systems off to the north of the country, meaning the far north-west of the UK gets glancing blows from these systems while the rest of the country has more settled conditions.

We expect the jet stream to move into this position over the next few days.

Leading prediction models from forecasting centres around the world all seem to be in agreement about this development – hence the unusually high level of certainty in the forecast. But, of course, forecasts can still change – so do stay in touch with the latest in our 5-day outlook and out to 30-days ahead.








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