Guest Blog from the RAC: Ploughing on

The RAC foundation has produced a report looking into winter resilience on the roads.

The report found that there was good preparation for the winter of 2012/2013 and that local highways authorities and councils were helped by generally good advance warning of the arrival of harsh weather. According to the report, “forecasting from the Met Office was to a high standard.” Also the majority of local highways authorities responded well to the snow and ice seen across much of the country earlier this year. There was no repeat of the salt shortages which helped create major disruption during the cold spells of winter 2009/10.

However the report said that as the climate appears to change we should not confuse extreme weather with rare weather, and if we continue to experience more frequent periods of inclement conditions then drivers will have to change their travel expectations and their view of what is ‘normal’.

Although there is evidence that more road users are taking notice of weather warning and being prepared, drivers need more advice on the potential benefits of winter tyres and ‘add-ons’ such as snow socks and snow chains. Drivers also need to be reminded of the importance of simple measures such as maintaining adequate tread depth on their normal tyres.

More information about Met Office weather warnings and for advice in what to do in severe weather you can visit the Met Office website.

Guest Blog: Risk of summer drought no greater than average

There have been some reports in the press that dry weather in May will bring a return of drought conditions.

Here Victoria Williams, Drought Advisor at the Environment Agency, explains what the risks currently are.

Every week we measure water resources in England to assess how dry the soils are and how much rain they can soak up, the amount of water flowing in rivers, stored below ground in aquifers and above ground in reservoirs, and the outlook for the coming months.

Our latest water situation report details a positive outlook for water resources in the coming months. 2012 was the second wettest year on record, and despite a relatively dry start to 2013, river levels are normal or above normal at the majority of our monitoring sites. We also look ahead by modelling how rivers and groundwaters may respond to different future rainfall patterns over the summer. The results shows a positive picture even if rainfall is below average and point to the risk of drought this summer being no greater than average.

However it is still as important as ever to use water wisely. If the weather does turn hot and dry there could be localised impacts on rivers and the environment. Modelling suggests that a changing climate could reduce some river flows by up to 80 per cent during the summer in the next 40 years – increasing the challenge of ensuring there is enough water for people, business, farmers and the environment.

NASA International Space Apps Challenge London

The Met Office hosted the NASA led International Space Apps Challenge at the Google Campus in London on the weekend of the 20 – 21 April.

Chris Gerty, from the Open Innovation Programme at NASA was at the London event and thanked the Met Office for making the weekend such a success.

More than 85 people attended the event from across the UK and Europe, making 13 different teams working on challenges over the weekend. See all the pictures from the weekend on our Flickr account.

Two challenges from London will go forward for global judging and these were decided by a panel of three judges, Chris Gerty from NASA, Irini Papadimitriou, Digital Programmes Assistant Manager at the V&A and Phil Evans, Government Services Director at the Met Office.

The two winning challenges from London were People of the Soil and T-10.

People of the Soil developed a low cost digital soil testing kit, web and SMS protocols and a web application to collect and share soil data globally.

T-10 created an app that astronauts can use on the Space Station to alert them to suitable times to photograph specific parts of Earth.

These will now be judged against other winning challenges globally, with winners being announced by NASA in the coming weeks. Follow @spaceappslondon to find out which challenges win NASA’s global judging next month.

Countdown to NASA Space Apps Challenge

This weekend will see the Met Office again linking up with sites across the world for the NASA International Space Apps Challenge.

This year, the Met Office is the European lead event for the Space Apps Challenge, with other events in the UK being held in London, Glasgow, York and Leicester.

In Exeter, over 70 people will be collaborating on challenges which have been submitted by NASA teams and other contributors around the globe.

One challenge designed by Catherine Muller of Birmingham University and Michael Saunby of the Met Office is Smart Cities, Smart Climate. The challenge will look at how sensor networks in cities can be used to monitor the climate in urban areas.

As more of the world’s population now inhabit towns and cities, and the part of the world’s surface covered by built-up environments is growing, Urban environments are becoming increasingly important and relevant to study. Therefore much more data and tools for analysing that data are required.

Spaces are still available for Space Apps Challenge in Exeter. You can follow all the action from the weekend on Twitter @spaceappslondon and @spaceappsexeter.

March is joint second coldest on record

Provisional full-month Met Office figures for March confirm it has been an exceptionally cold month, with a UK mean temperature of 2.2 °C.

This is 3.3 °C below the 1981-2010 long-term average for the month, and ranks this March as joint second coldest (with 1947) in our records dating back to 1910. Only March 1962 was colder, with a record-breaking month mean temperature of 1.9 °C.

In an unusual turn of events, this March was also colder than the preceding winter months of December (3.8 °C), January (3.3 °C) and February (2.8 °C). This last happened in 1975.

Looking at individual countries, the mean temperature for England for March was 2.6 °C – making it the second coldest on record, with only 1962 being colder (2.3 °C). In Wales, the mean temperature was 2.4 °C which also ranks it as the second coldest recorded – with only 1962 registering a lower temperature (2.1 °C). Scotland saw a mean temperature of 1.3 °C, which is joint fifth alongside 1916 and 1958. The coldest March on record for Scotland was set in 1947 (0.2 °C). For Northern Ireland, this March saw a mean temperature of 2.8 °C, which is joint second alongside 1919, 1937, and 1962. The record was set in 1947 (2.5 °C).

This March was also much drier than average for the UK, with 62.1mm of rain falling during the month – just 65% of the 95.1mm average. Scotland was particularly dry, seeing 49.5mm of rain which is 35% of its long term average for the month.

Sunshine hours were also slightly down compared to average, with 82.9 hours for the UK notching up 81% of the average.

The cold and dry conditions seen in March were largely due to high pressure dominating UK weather patterns, allowing cold and relatively dry air to move in from the east. While this pattern is set to continue through the first week of April, milder and more unsettled conditions are expected to move in for the start of next week. You can stay up to date with the latest information with the Met Office’s forecasts.

March 2013	Actual	Difference from average	Actual	% of average
Regions	°C	°C	mm	%
UK	2.2	-3.3	62.1	65
England	2.6	-3.6	64.4	101
Wales	2.4	-3.4	86.2	74
Scotland	1.3	-2.9	49.5	35
N Ireland	2.8	-3.1	74.1	78
England & Wales	2.6	-3.6	67.4	95
England N	1.8	-3.7	56.4	75
England S	3	-3.5	68.6	118

March – top five coldest in the UK

1	1962	1.9 °C
2	2013	2.2 °C
2	1947	2.2 °C
4	1937	2.4 °C
5	1916	2.5 °C

Met Office continues to drive forward research on long-range forecasting

The BBC Radio 4 ‘Today’ Programme have run a story this morning regarding the advice the Met Office gave to our government customers ahead of the exceptionally wet weather of April to June 2012.

This was an extreme period of weather that saw a marked change from dry conditions to very wet conditions in a very short period of time.

Following the exceptionally wet weather of late spring 2012 the Met Office provided a full report into the possible reasons for the switch from dry to wet conditions. Our report states that the advice provided in the long-range outlook for April to June 2012 issued in March 2012 ‘was not helpful’ to our government customers.

However, looking at the skill of these outlooks over many individual forecasts clearly shows that they provide useful advice to their specialist users on over 65% of occasions. In addition these outlooks are never used in isolation but form one part of a range of forecasts from the Met Office including regular monthly outlooks and highly accurate 1 to 5 day forecasts and warnings.

Facing up to the challenge of long-range forecasting

The science of long-range forecasting is at the cutting edge of meteorology and the Met Office is leading the way in this research area. We are continuing to work hard to develop the science of long-range forecasting. We are confident that long-range outlooks will improve progressively and that the successes we have achieved in other parts of the world already will, in the future be mirrored in the UK.

The Met Office constantly reviews the accuracy of our forecasts across all time scales and is recognised by the World Meteorological Organization as one of the top two national weather forecasting services in the world. We also routinely verify our short-range forecasts on our website.

The ‘big switch’ of April 2012

During March 2012 the La Nina event that had persisted from 2009 was finally waning in the Pacific (as predicted by the seasonal forecast system), although many parts of the global oceans and tropical weather patterns still retained characteristics associated with La Nina. In the northern hemisphere the jet stream was very disturbed, resulting in a wave pattern of high and low pressure regions. The UK was positioned under a strong high pressure region resulting in very dry and warm conditions. In April, the wave pattern underwent a significant shift to bring the UK under the influence of strong low pressure, with prevailing south-westerly flow and heavy rainfall.

As detailed on ‘Today’, one of the potential causes of this shift in the northern hemisphere circulation may have been associated with a shift in tropical weather patterns. In particular, this may have been caused by a strong Madden Julian Oscillation (MJO) which occurred in March. This is a large-scale tropical phenomenon which leads to disturbed weather patterns over a timescales of typically 30-60 days. This changes originating over the Indian Ocean may have influenced our northern hemisphere weather regimes. Understanding the initiation of an MJO event is, however, largely unpredictable, and remains one of the great unsolved challenges of tropical meteorology.

Due to the fact that the initiation of an MJO is largely unpredictable – combined with knowledge that often subtle, and sometimes small, shifts in hemispheric circulation patterns can make all the difference between fine, dry weather and unsettled, wet weather over the UK – it is very unlikely that its impacts could have been anticipated in any forecasts for the coming months issued in early and mid-March.

A complicated world

Finally, although one reason for the switch in the fortunes of our weather in 2012 may have been the MJO, there are other parts of the climate system which we increasingly recognise as having an influence on our weather patterns. These include the North Atlantic Ocean temperatures, solar variability, the circulation of the upper atmosphere – the stratosphere – and of increasing interest, the changing state of the Arctic.

Better understanding and representing the drivers of predictability in the global climate system that influence our weather patterns is as ever a priority for Met Office research in order to deliver improved advice and services on all timescales.

• Continually improving our forecasts
• How accurate are our public forecasts?
• What you say about our forecasts and warnings
• Read case studies about our forecasts

Is there a UK ‘heatwave’ on the way?

There have been some headlines today suggesting the Met Office has forecast a ‘heatwave’ by the end of spring.

The articles reference a line from our March to May three-month outlook for contingency planners which refers to how our Spring weather can change depending on where large areas of ‘blocking’ high pressure systems lie in relation to the UK – something we recently wrote about when contrasting the weather this March to that of last year.

This is not, however, a forecast of what the weather is expected to be like at the end of the spring or whether a ‘heatwave’ is likely or not, but is an indication of how average temperatures may differ from normal throughout the whole three month period of March, April and May.

Clearly this is the time of year when temperatures rise in response to the sun getting higher in the northern hemisphere sky, the days get longer and continental Europe warms up. So we will undoubtedly get some warmer spells of weather as the months go on and these will be picked up in our accurate five-day forecasts, as well as our forecasts out to 30 days ahead, which gives a more general view of the weather ahead over a longer-timescale. It is our accurate five-day forecasts and weather warnings provide the best possible advice and detail on what weather to expect in the UK.

This week is set to remain very cold with further wintry flurries in places.

Five things you might not know about thunderstorms

1. Lighting can strike twice. The empire state building in New York has been struck by lightning as many as 48 times in one day.
2. The average flash of lightning would light a 100 watt light bulb for three months.
3. Lightning can strike in volcanic ash clouds. Not much is known about volcanic lightning, but we’re using it to help track ash clouds.

Volcanic lightning

4. Thunderstorms can trigger asthma. The Met Office has worked with the NHS and Asthma UK to try and understand why.
5. The most thundery part of the earth is the island of Java where the annual frequency of thunderstorms is about 220 days per year.

Setting the record straight in the Daily Mail

In response to our complaint to an article by James Delingpole in the Daily Mail on 10 January 2013 the Daily Mail has now published a response from the Met Office Chairman on its letters page.

Met Office mettle

James Delingpole’s views misrepresent the Met Office’s reputation for world-class weather and climate forecasting and research (Mail). The UK can be rightly proud that the Met Office is among the world’s top two national weather forecasting services.

We’re proud that, in independent surveys, more than 90 per cent of the public regard our warnings as useful and more than 80 per cent of the UK public trust our forecasts and warnings. This respect for our professionalism and impartiality has been built over 150 years of forecasting for the nation.

We aim to use our world leading scientific expertise to protect life and property and increase prosperity and wellbeing right across the UK. We provide impartial services ranging from forecasts and warnings to the public, services to transport operators, so we can fly, drive or sail safely, and advice to the energy, retail and health sectors so we can all go about our daily lives safely and efficiently.

Our forecasts on radio, TV, mobile phone apps and newspapers are a source of daily interest as well as essential advice to the public.

Whatever a journalist’s views are about climate change – and they have a right to air them – let’s not degrade the institutions on which the public rely.

GREG CLARKE,

Met Office chairman, Exeter, Devon.

Although this does not fully address all the issues we had with the original article we do accept that a published letter recognises our concerns and has taken steps to resolve some of them. The Daily Mail has also offered to append this letter to the original article.

We are grateful to the Daily Mail for dealing with our objections to the inaccuracies in the original article and the efforts made to find a constructive resolution. We are, as ever, grateful for the role the Daily Mail, and other print, online and broadcast media have in bringing key forecasts, warnings, and science to the attention of the public.

Why does it feel so cold? A guide to ‘feels like’ temperatures

With bitterly cold conditions across parts of the UK just now, have you been asking yourself why it can feel so much colder in the wind?

The temperatures that you normally see on our website represent the temperature of the air, but this takes no account of how we actually experience the temperature. It is our ‘feels like’ temperature that gives you a better idea about how the weather will actually feel when you step outdoors.

Our ‘feels like’ temperature takes into account wind speeds and humidity to assess how the human body actually feels temperature.  For example in winter a strong wind can feel much colder than the measured temperature would indicate. The impacts of the temperature and wind combined can be much greater  than each on their own and the feels like temperature allows users to make a better assessment of conditions outdoors.

But how do you actually calculate the ‘feels like’ temperature?

We calculate a ‘feels like temperature by taking into account the expected air temperature, relative humidity and the strength of the wind at around 5 feet (the typical height of an human face) combined with our understanding of how heat is lost from the human body during cold and windy days.

On windy days the speed of moisture evaporation from your skin increases and serves to move heat away from your body making it feel colder than it actually is. The exception to this rule, however, is when higher temperatures are concerned. At higher temperatures, wind chill is considered far less significant. Instead humidity plays a greater role. When a human being perspires, the water in his or her sweat evaporates. This results in the cooling of the body as heat is carried away from it. When humidity is high, the rate of evaporation and cooling is reduced, resulting in it feeling hotter than it actually is.

Using these facts we use a formula to adjust the air temperature based on our understanding of wind chill at lower temperatures, heat index at higher temperatures and a combination of the two in between.

You can get ‘feels like’ temperatures on our five day forecast and on our Android, iPhone and Windows Phone apps.