First half of April has been dry and warm

17 04 2015

Early statistics up to the 15th of April show that month so far has been generally settled and warm, with limited rainfall in most areas.

The mean temperature for the UK was 8.2C, which is 0.8C above the long-term (1981-2010) average for the whole month.

Daytime temperatures have risen to well above average in many areas, especially in the south, with the year’s highest temperature so far of 25.1C recorded at Frittenden in Kent on the afternoon of the 15th. This is the highest April temperature anywhere in the UK since 2011.

The UK as a whole has seen average maximum temperatures 1.4C above normal, though much closer to average in coastal parts of northwest England and western Scotland.

Map shows the UK mean temperature for 1-15 April compared to the whole month average.

Map shows the UK mean temperature for 1-15 April compared to the whole month average.

Rainfall has been well below normal so far in most areas. After 15 days of the month you’d expect about 50% of the full-month average to have fallen in a ‘normal’ April, but the UK has seen just 35% (25.2mm). However, there was some persistent and heavy rain across parts of northwest Scotland on 13th and 14th, and parts of western Scotland have had most of the whole-month average already.

It has also been rather a sunny month so far for most parts of the UK, with 63% of the full-month average already – again you would expect around 50% by mid-month.

The forecast for this weekend is for a good deal of dry and bright weather. However, it’s still far too early to judge how this April will finish overall, with half of the month still to add in to the statistics.

Mean Temperature Sunshine hours Rainfall  
1-15 Apr
Actual Diff to Avg Actual % of Avg Actual % of Avg
  degC degC hours % mm %
UK 12.9 1.4 92.8 63 25.2 35
England 14.0 1.6 98.4 63 14.1 24
Wales 13.5 1.9 92.0 60 20.1 22
Scotland 10.8 1.1 85.8 64 43.7 48
N Ireland 12.8 1.2 81.5 56 32.6 44

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.





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.





March continues sunny theme for UK

31 03 2015

Following the sunniest winter in records dating back to 1929, March has continued the trend with above average sunshine hours according to early Met Office statistics.

Map showing sunshine hours between 1-29 March compared to the full-month long-term average.

Map showing sunshine hours between 1-29 March compared to the full-month long-term average.

Up to the 29th of the month, there had been 115.0 hours of sunshine which is slightly above the full-month long-term (1981-2010) average of 101.8 hours.

Northern Ireland has been particularly sunny compared to average, with 126.9 hours of sunshine so far this month – which is well ahead of its long-term March average of 97.7 hours.

It has also been a slightly drier than average month up to the 29th, with 80.4mm of rain for the UK so far making up about 85% of the long-term average for the whole month (95.1mm). We’d expect to have had about 94% of the full-month average by this stage of the month.

England has been particularly dry, with the 39.4mm notching up just 62% of the full month average (64.0mm).

Wales and Northern Ireland were also fairly dry (notching up 74% and 78% of their full month average respectively), whereas Scotland is slightly wetter than average – having seen 148.2mm of rain which is just over the full-month average.

When it comes to temperatures – the month has been spot-on average up to the 29th, with a mean temperature of 5.5C.

Looking closer at individual countries, England, Wales and Northern Ireland were all slightly colder than average (by no more than a few tenths of a degree), while Scotland again bucked the trend with slightly above average temperatures (by 0.3C).

Overall the month has been fairly average so far, with no records broken. The final figures are likely to change slightly once the final two days of the month are added.

You can explore Met Office statistics on our UK Climate pages.

UK statistics for 1-29 March:

Mean Temperature Sunshine hours Rainfall  
1-29 March
Actual Diff to Avg Actual % of Avg Actual % of Avg
  degC degC hours % mm %
UK 5.5 0.0 115.0 113 80.4 85
England 6.1 -0.1 122.0 113 39.4 62
Wales 5.4 -0.4 118.7 117 86.1 74
Scotland 4.4 0.3 100.2 108 148.2 105
N Ireland 5.6 -0.2 126.9 130 74.3 78




Holiday Dust

24 02 2015

At this time of year, many of us are in search of some winter sun, and a popular destination for Brits abroad is Egypt.

Typical conditions in Cairo at this time of year are fairly warm, dry and sunny. On average in February you could expect to see daytime highs of 21C, 8 hours of sunshine per day, and 1 wet day in the whole month. However, there may be some disappointed holidaymakers at the moment, as rather than sunshine; there is dust in the forecast. A dense dust plume has been developing across Libya and Egypt and will continue to grow over the coming days.

A deep area of low pressure in the central Mediterranean has given some very unsettled weather over recent days, and will continue to bring heavy rain and snow to northern parts of Algeria, Tunisia and perhaps western parts of Libya over the next few days. Very strong winds around the low will generate dust storms and sand storms and these will move across the rest of Libya and into Egypt during the first part of this week.

The dust storms will be severe and widespread enough to cause some disruption to air travel in the region, with perhaps some public health issues also.

The deep pink area in this satellite picture is the dust, and the line of dust stretches right up towards Greece.

The deep pink area in this satellite picture is the dust, and the line of dust stretches right up towards Greece.

These intense dust storms are often called Haboobs, which were first named in Saharan Sudan. They are frequently associated with thunderstorms or even small tornadoes, and usually last about three hours. The storms tend to develop late in the day during summer, and are sometime followed by rain. They can transport and deposit huge quantities of sand or dust, moving as an extremely dense wall that can be up to 100 km wide and several kilometers high.

Dust storm

For more information about the weather abroad, visit our holiday weather section.





‘Super tides’, the weather and coastal flood risk

20 02 2015

UPDATED 27/02/2015 – this blog has been updated under the section ‘So what are ‘super tides” with the help of the National Oceanography Centre.

In this joint blog from the Environment Agency and the Met Office, we look at the issue of so-called ‘super tides’.

There has been a lot of media coverage about the potential impact of so-called ‘super tides’ which are due from today (Friday, 20 February) through to Monday.

So what are ‘super tides’?

Tides are governed by the gravitational pull of the moon and, to a lesser extent, the sun. Because the sun and moon go through different alignment, this affects the size of the tides.

When the gravitational pull of the sun and moon combine, we see larger than average tides – known as spring tides. When the gravitational pulls offset each other, we get smaller tides known as neap tides. We see two periods of spring and neap tides roughly every month.

Yet some spring tides are higher than others. This is because tidal forces are stengthened if the moon is closest to Earth in its elliptical orbit (astronomers call this perigee). Tide forces are also enhanced when the sun and the moon are directly over the equater. For ths Sun this happens on or around 21 March or September (the equinoxes). Spring tides are always higher at this time of year. The moon’s orbit also takes it above and below the equator over a period of 27.2 days. Just as with the Sun, the tide generating forces are at their greatest when the moon is directly overhead at the equator.

Very large spring tides occur when these astronomical factors coincide. Approximately every 4.5 years the moon is closest to the Earth, and is also overhead at the equator, at either the March or September equinox.

In some places, these extreme tidal conditions can cause water levels to be 0.5m higher than a normal spring tide, but the weather can have a greater impact than even these largest of tides

What is the role of the weather in sea levels?

It’s important to realise that just because we are expecting big astronomical tides over the next few days, these won’t cause the highest sea levels we’ve seen – even in the last few years. That’s because the weather can have a much bigger impact on sea level than the 18-year tidal cycle.

Strong winds can pile up water on coastlines, and low pressure systems can also cause a localised rise in sea level. Typically the difference in water level caused by the weather can be between 20 and 30cm, but it can be much bigger.

On the 5th December 2013, for example, the weather created a storm surge that increased the water level by up to 2 metres. Although an estimated 2,800 properties flooded, more than 800,000 properties were protected from flooding thanks to more than 2,800 kilometres of flood schemes. The Environment Agency also provided 160,000 warnings to homes and businesses to give people vital time to prepare.

This highlights the importance of the Met Office and the Environment Agency working together to look at the combined impact of astronomical tides, wind, low pressure and waves on flood schemes to assess the potential impacts for communities around our coast.

Will we see coastal flooding this weekend?

Given the height of the tides there may be some localised flooding. Weather isn’t playing a large part in water levels over the next few days, although strong winds on Monday are likely to generate some large waves and push up sea levels slightly. This is nothing unusual for winter. You can see more about what weather to expect with the Met Office’s forecasts and severe weather warnings.

The Environment Agency and the Met Office are working together to closely monitor the situation, and the Environment Agency will issue flood alerts and warnings as required.

In the Humber Estuary, for example, we are expecting total water levels of between 4.20-4.39 metres – well below record levels of 5.22m.

John Curtin, Environment Agency’s Director of Incident Management and Resilience, said:  “We are monitoring the situation closely with the Met Office and will issue flood alerts and warnings as required.

“It’s possible we could see some large waves and spray and urge people to take care near coastal paths and promenades and not to drive through flood water.

“However, we can only get a warning to you if you’ve signed up to our free service. People can also see their flood risk and keep up to date with the latest situation on the GOV.UK website at https://www.gov.uk/check-if-youre-at-risk-of-flooding or follow @EnvAgency and #floodaware on Twitter for the latest flood updates.”

For those in Scotland, you can see flood updates for your area on the SEPA website here.

For those in Wales, you can see flood updates in English and Welsh on the Natural Resources Wales website here.

You can also see John explaining the Environment Agency’s flood warnings here:





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.





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.





How a strong jet stream is affecting aviation

13 01 2015

We often talk about the jet stream and its impacts on UK weather – but it can have an even more direct effect on aviation as covered in the media in recent days.

The jet stream is a band of fast moving winds high up (around 5-7 miles) in the atmosphere. It usually travels eastwards around the northern hemisphere but regularly changes its track and strength.

Pilots travelling east, say from the US back to Europe, use the jet stream to cut journey times and save fuel – just like a cyclist uses a tailwind on a bike.

This has always meant journey times in the northern hemisphere are faster when travelling east than heading west (when airlines avoid the jet stream).

Recently the jet stream has been particularly strong over the north Atlantic, with winds of more than 250mph being seen at times.

You can find out more about the jet stream in our YouTube video:

This has had an impact on flying times – with eastbound trans-Atlantic services arriving well in advance of their scheduled times. Some types of passenger aircraft have reputedly seen record breaking journey times.

All this of course has a knock-on effect for airports as schedules are carefully planned to ensure there’s room, not to mention boarding gates, for each aircraft when it’s due to land. That has meant the strong jet stream creates a logistical challenge for airports across Europe.

The Met Office has been helping airlines and airports to plan ahead with its forecasts of the strength of the jet stream through its role as a World Aviation Forecasting Centre (WAFC).

There are only two WAFC centres in the world; the UK and Washington, in the US. The two centres provide aviation charts for the globe, highlighting conditions between 10,000 and 63,000 feet.

These charts show the location and strength of the jet stream, as well as other important aviation factors, such as clear air turbulence, cumulonimbus (storm producing) clouds, volcanoes and tropical storms. Both centres operate 24 hours a day and throughout the year.

Airlines use our upper-air wind forecasts to predict flight times at cruising altitude. For transatlantic flights during 2012, the average difference between the predicted flight time and the actual flight time was about one minute. This means that our aviation customers can accurately calculate the fuel load required for each flight. Our WAFC charts save airlines globally £2.7 billion a year because our forecasts help them fly safely and efficiently.

Accurate forecasts enable pilots, airlines and airports to assess flying times in advance and use that information to try to ensure things run as efficiently as possible on the ground.





2014: A year in weather

31 12 2014

2014 has been another year of eventful weather across the UK. Here we take a look at some of the year’s more notable aspects.

Temperature

The obvious headline from 2014 is that it will be the warmest year in our UK record dating back to 1910, knocking 2006 from its top spot.

Using figures up to 28 December then assuming average conditions for the last three days of the year, the expected mean temperature for the UK is 9.9 °C. This beats the previous record of 9.7 °C set in 2006 and means all the UK’s top eight warmest years have happened since 2002.

Despite the overall warmth, there were no record-breaking months – it’s just a case that 11 out of 12 months (August being the exception) were warmer than average. Although individual months were unremarkable, it was the persistence of the warmth that was unusual and together they add up to something record-breaking.

It’s also worth noting it’s set to be the warmest year on record in the Met Office’s Central England Temperature (CET) series, which dates all the way back to 1659. The mean temperature estimate for the year is 11.0 °C, which would just beat the record of 10.9 °C set in 2006.

Human influence on the climate is likely to have substantially increased the chance of breaking the UK and CET temperature records. Estimates from the Met Office suggest that it has become about ten times more likely for the UK record to be broken as a result of human influence on the climate.

Rainfall

It has also been a notably wet year, with the rainfall up to 28 December totalling 1290.0 mm. This ranks 2014 as the UK’s 5th wettest year in the records back to 1910 and it is only 5mm away from 4th placed 2008, so this year could step a notch higher when the final two days of the year are included.

The first two months of the year really set us on the path to this high rainfall total, as both January and February were the third wettest in the record. The winter of 2013/2014 was especially wet across south-east England and it was the wettest winter for the UK in a series from 1910, and in the England and Wales precipitation series from 1766.

May, August, October and November were also all wetter than average. August was especially wet in northern Scotland – here it was the wettest August in a series from 1910. The other months were mostly drier than average, with September being notably dry – in fact it was the driest month on record for the UK in a series from 1910 with just 22.1 mm of rain.

Weather through the months

The year started with two spells of very wet and stormy weather from mid-December to early January, and late January to mid-February, as one deep low pressure system followed another. These brought extremely strong winds and heavy rain to all parts of the country, with widespread disruption across the UK.

A number of factors contributed to the unusually stormy weather, particularly the influence of a powerful Atlantic Jet Stream. You can see more about these in a report written by the Met Office. You can also explore the evolution of this spell of weather in our climate events pages.

The start of spring saw the weather calm down – with March bringing some much-needed drier and more settled weather. The spring (March – April – May) was warmer than average, while rainfall for spring ended up very close to average, which helped the UK recover from its wettest winter on record.

June and July saw a good deal of dry and fine weather, with above average temperatures and sunshine hours combining with below average rainfall. Although there were no major heatwaves, these months made for one of the better periods of summer weather that we’ve seen in recent years; summer 2013 also brought plenty of fine, settled weather in contrast to summers 2007 to 2012.

August was more unsettled, however, with above average rainfall and it was the only month of the year with below average temperatures. On 10th August the remants of ex-hurricane Bertha brought heavy rain and some flooding to parts of north-east Scotland.

September then immediately turned the tables, being exceptionally dry with above average temperatures. However, October and November brought some more typically autumnal weather and the autumn (Sep-Oct-Nov) ended up being fairly average overall, although again it was notably mild and with a marked absence of frosts.

December has seen the coldest temperatures of the year so far for all parts of the UK, but the lowest values for the year remain unusually high compared to previous years. The month so far (using figures up to the 28th of the month) has also been milder than average overall, despite the late cold snap. Rainfall looks set to be around average, while sunshine amounts are well above the norm.

Some 2014 extremes:

Max temp – 32.3 °C at Gravesend, Kent on 18 July. This is fairly typical: during most years we would expect the temperature to reach the low 30s in a few locations.

Min temp – -9.0 °C at Cromdale, in Moray, Scotland on 27 December. By contrast, this is unusually mild. During most winters we would expect the temperature to fall below -10 °C, if not -15 °C, most likely in Highland Scotland.

Max wind gust – 109mph at the Needles Old Battery on the Isle of Wight on 14 February

Wettest day – 146.8 of rain at Ennerdale, Black Sail, Cumbria on 6 March 2014. The high fells of the English Lake District are climatologically one of the wettest parts of 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








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