Estimates of the mean temperature for the whole season have been made based on data from 1 March up to 15 May as well as an assumption of average conditions through to the end of this month. The final figures could therefore be different, depending on the temperatures we actually see up to the end of May.

The estimates suggest the mean UK temperature for spring will be around 6.1 °C, which would make it the 6th coldest spring in national records dating back to 1910 and the coldest since 1979 when the mean temperature was 6.0 °C.

The estimated figure this year goes against recent form for spring, with eight of the past ten years being above the long-term (1981-2010) average for the season of 7.7 °C.

However, looking further back, the most recent colder spring of 1979 came in the middle of a long run, lasting from 1962 to 1989, of springs which were almost all colder than the current average*.

This year’s particularly cold spring was heavily influenced by an exceptionally cold March which had a mean temperature 3.3 °C below the long-term average. April and May (so far) have been less cold, but have also registered slightly below average mean temperatures.

The colder than average conditions have been caused by frequent east and northerly winds which have brought cold air to the UK from polar and northern European regions.

This spring also looks to be slightly drier than average, with an estimate of about 214 mm of rain which would be roughly 90% of the average amount we would expect through the season. This isn’t that notable when compared with the the springs of 2010 and 2011, which were much drier – notching up 79% and 70% of the average respectively.

Estimated provisional statistics for spring 2013

*The Met Office operates 30-year climate averages which are updated every decade. Looking at the 30-year averages of 1961-90, 1971-2000 and the current climate averages of 1981-2010, you can see the average mean temperatures for spring have increased over that period. This means defining what is ‘below-average’ depends on which 30-year period is used. All references in this article use the current 1981-2010 climate averages.

30-year period                 Average spring UK mean temperature

1961-1990                                            7.1 °C

1971-2000                                            7.4 °C

1981-2010                                            7.7 °C

Related articles

• April drier and colder than average
• Why was the start of Spring so cold?

The research paper looked at a ‘best estimate’ of the warming expected when the concentration of carbon in the atmosphere is doubled over pre-industrial levels (known as the Transient Climate Response).

Alexander Otto, Research Fellow in Climate Decisions at the Environmental Change Institute, University of Oxford, was the lead author of the research.

He has written an article discussing the science and the implications of the research which can be seen on the Research News pages on our website.

Here is a short extract from Alexander Otto’s article :

“We published a paper in Nature Geoscience on Sunday giving a new best-estimate of 1.3°C for the Transient Climate Response, or the warming expected at the time carbon dioxide reaches double its pre-industrial concentration, using data from the most recent climate observations.

This best-estimate is lower than the HadGEM2 [one of the Met Office climate models] TCR value of 2.5°C and it is also 30% lower than the multi-model average of 1.8°C of the CMIP5 models used in the current IPCC assessment. Does this mean that the Met Office’s advice to government is based on a flawed model? Certainly not.

It is well acknowledged by all that the HadGEM2 model is at the top end of the range of TCR values in CMIP5, but we need a diverse range of TCR values to represent the uncertainties in our understanding of climate system processes. And the Met Office’s advice to government, like any solid policy advice, is based on the range of results from different models, not just their own.

…

The ‘warming pause’ over the recent decade does not show that climate change is not happening. And it certainly does not mean that climate scientists are “backing away” from our fundamental understanding.

Every new decade of data brings new information that helps reduce uncertainties in climate forecasts. In some ways, the picture changes surprisingly slowly for such an intensely scrutinised problem… This study highlights the importance of continued careful monitoring of the climate system, and also the dangers of over-interpreting any single decade’s worth of data.”

Where do they occur and how do they form? - Most continents have regions with favourable conditions for tornado formation. The central and southern states of the USA have the most violent tornadoes in the world due to a unique combination of geographical and meteorological circumstances. This region, from Nebraska through Oklahoma to Texas, is known as ‘Tornado Alley’. Here cold dry air moving south and east from the Rocky Mountains meets warm moist air from the Gulf of Mexico, giving perfect conditions for severe ‘supercell’ thunderstorms to develop. These thunderstorms can often produce tornadoes, especially in late spring and summer.

Tornadoes form as air starts to spin due to winds at different heights blowing at different speeds, creating wind shear. This causes the air to start spinning horizontally. If this gets caught in a supercell updraft, the updraft tightens the spin,  speeds it up and tilts it towards the ground.

As tornadoes develop, funnel shaped clouds extend from the base of the cloud. It is only when these funnel clouds touch the ground that we get a tornado. If the funnel cloud touches down at sea we get a waterspout.

What happened this time? - Air masses have been colliding over the last few days. Unusually cool dry air from the Rocky Mountains and the northern plains, hot dry air from the desert and warm, humid air from the Gulf of Mexico have collided in a region stretching from Texas to Chicago, forming severe supercell thunderstorms and, in some instances, large tornadoes.

How severe was the tornado that hit Oklahoma? - It is virtually impossible to measure the speed of winds in tornadoes. Their strength is estimated by the amount of damage they cause. They are categorised using the Enhanced Fujita (EF) Scale of zero (weak) to five (strong). The tornado that hit Oklahoma yesterday is estimated to have been EF5 with winds of up to 200 mph. It was up to two miles wide and on the ground for 45 minutes. The tornado that hit Oklahoma yesterday was of a similar strength to the worst ever tornado to hit the area on 3 May 1999.

What about tornadoes in the UK? - It is claimed that the UK gets more tornadoes per square kilometre than the USA, but not more tornadoes in total. On average, around 30 tornadoes are reported each year in the UK. However, these are generally much weaker than their American counterparts.

How will climate change affect tornadoes? - It is currently not possible to make a link between climate change and tornado activity. Climate change may have a number of effects on atmospheric conditions that may or may not favour tornado formation, the relatively short and unreliable record of tornado activity makes it difficult to determine a definite trend in this. Climate models are currently unable to resolve small-scale phenomena such as tornadoes, and no models exist which can use climate model data to predict future tornado activity.

Related articles

• How often do we have tornadoes in the UK?

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.

The long-term average over the period 1980–2010 is 12 tropical storms. The last three hurricane seasons have all recorded above average tropical storm activity.

The most likely Accumulated Cyclone Energy (ACE) index — a measure of the strength and duration of storms over the season — is 130, with a 70% chance that the index will be in the range 76 to 184; the 1980–2010 average ACE index is 104.

For the first time this year, the Met Office are also releasing a forecast of the number of hurricanes (storms with winds of at least 74 mph), following the success of experimental forecasts produced throughout the 2012 hurricane season.

Between June and November 2013 the best estimate is for 9 hurricanes, with a 70% chance that the number will be in the range 4 to 14; the 1980–2010 average is 6 hurricanes.

Overall, these indicators point to a preference for above-average activity this year.

The evolution of the El Niño/La Niña cycle over the next few months is likely to play a large part in the North Atlantic hurricane season.

Joanne Camp, climate scientist at the Met Office, said: “El Niño conditions in the Pacific can hinder the development of tropical storms in the Atlantic whereas La Niña conditions can enhance tropical storm activity, so how these conditions develop will be important for the storm season ahead.”

The tropical storm forecast is produced using the Met Office’s new seasonal prediction system GloSea5. The model has higher resolution than its predecessor, with better representation of the complex physical processes that cause tropical storms and hurricanes. The forecast also uses information from the seasonal prediction system of the European Centre for Medium-Range Weather Forecasts (ECMWF).

For regular updates on tropical cyclones worldwide follow @metofficestorms on Twitter.

The recent activity on the Sun has now decreased back to levels we would normally expect at this point in time, close to a maximum of the 11-year solar cycle.

This follows a period where a sunspot, identified as 1748, emitted a number of powerful solar flares which were directed away from Earth.

There was a concern that another eruption from 1748 would be more directly aimed at Earth as it moved round with the Sun’s rotation. However, 1748 has reduced in size and has seen no significant activity for more than 48 hours.

While the risk of impacts on Earth has decreased, it is still possible that high levels of activity will re-emerge from 1748 while it is facing Earth. The Met Office will continue to monitor the situation.

Mark Gibbs, Head of Space Weather at the Met Office, said: “This sunspot was particularly active last week, sending out one solar flare which was the largest measured for over a year. Fortunately its eruptions were not directed at Earth and we saw very minimal impacts.

“We have observed a decrease in the spot’s activity in the past couple of days and, while a risk remains, we are now at a normal level of activity for this point in the solar cycle.”

Previous updates:

Updated on 17th May 2013

As per our blog article published yesterday, the Met Office continues to closely monitor the Sun following a recent surge in its activity related to a sunspot (identified by the number 1748).

This morning saw a Coronal Mass Ejection (CME), which is an eruption of electromagnetically charged gas (plasma), from the sunspot. The CME is due to catch Earth with a glancing blow which is not expected to cause any significant impacts.

There remains a low risk through to the end of next week that we could see a CME from 1748 which is aimed more directly at Earth, but after that the risk is expected to diminish.

We’ll continue to monitor the situation closely and provide updates if there are any changes.

It’s fairly common for eruptions from the Sun (often called “space weather”) to occur, and these are usually associated with sunspots – dark areas of intense activity on the surface of the star.

The eruptions from these spots come in several different forms, but if the events are of sufficient strength and directed towards the Earth, they can all cause impacts on our modern-day technology. Impacts range from minor interference to communication networks to temporary disruption to electricity supply, satellites and GPS navigation.

Over the past few days a sunspot, identified by the number 1748, has been the cause of many solar eruptions which have already caused some minor impacts.

NASA image showing one of the recent solar flares ejecting from sunspot 1748

Some of the eruptions have been in the form of Coronal Mass Ejections (CMEs), which are plumes of electromagnetically charged gas (plasma). These have been focused away from Earth so far, but, as the sun rotates, there is a chance the sunspot could emit a CME in our direction.

Mark Gibbs, Head of Space Weather at the Met Office, said: “If a strong CME were to be directed at Earth it could have some disruptive impacts, but at the moment the probability of this happening appears to be low.

“We’ll be keeping a close watch on the situation, particularly from Friday evening onwards, to advise on anything that could cause disruption to help the UK minimise any potential impacts. Hopefully this event will pass without the majority of people noticing, but it’s important we monitor the risk.”

Since February 2011, the Met Office has been working with a range of partners, including the US National Oceanic and Atmospheric Administration (NOAA), the British Geological Survey (BGS) and the UK Space Agency to develop a UK-based space weather forecasting service.

This monitors the Sun’s activity and then predicts how these changes are likely to affect the Earth’s environment. The Met Office Hazard Centre currently has forecasters trained in space weather forecasting, and awareness is being raised across different industry sectors to make them aware of their potential vulnerability and how we can help lessen the risks.

In the event of a CME, space weather monitoring can provide anything from 17 hours to 3 days advance warning – allowing vital time to prepare.

Solar activity is currently expected to be high as we are near the peak of an 11-year solar cycle, which sees the Sun’s activity increase and decrease over the period.

You can see more about space weather forecasting in our Youtube video.

For a full written summary of the weather in April visit the climate section of our website.

Your weather pictures

Thank you for sharing your weather pictures with us on Twitter, here’s some of our favourites.

@metoffice April showers from Friday eve in Shropshire: flic.kr/p/ef8rDm

— Rockwolf (@rockwolf74) April 29, 2013

.@metoffice crazy skies, rain, sun and a rainbow in Islington in North London on Saturday. #weather twitter.com/andrew_spires/…

— Andrew Spires (@andrew_spires) April 29, 2013

@metoffice Mammatus over Frimley twitter.com/cambriangirl1/…

— cambriangirl (@cambriangirl1) April 29, 2013

@metoffice twitter.com/shaunys10/stat…

— Shauny10 (@shaunys10) April 29, 2013

@metoffice a wet day in the lakes looking for respite from wind and rain twitter.com/aimcourses/sta…

— stuart smith (@aimcourses) April 29, 2013

@metoffice Snowy Nith… twitter.com/vickimead/stat…

— Victoria McNamara (@vickimead) April 29, 2013

Related articles

• March weather summary video and your photos (metofficenews.wordpress.com)

We can see three low pressure areas showing up as swirls of cloud to the north of Scotland near Shetland, north of Northern Ireland and off south-west England. The centre of the lows show up as cloud free areas.

The low to the south west has developed quickly through today and will bring strong winds this evening to parts of Cornwall.

Keep up to date with forecasts and warnings for your local area on our website.

Met Office warnings and what they mean

If a yellow warnings is issued: Be aware.

During a yellow warning for rainfall there may be some minor traffic delays due to slower traffic and outdoor events may be disrupted or cancelled. There may be localised flooding of fields, car parks and recreational land.

When an amber warning is issued: Be prepared.

An amber warning indicates the need to be prepared for some disruption of daily routines and travel only if well prepared as the journey may take longer. Some flooding of homes, businesses and transport connections is possible. Utility services (gas, electricity and water) may also be affected and protecting property will be needed (for example moving possessions upstairs and using sandbags).

A red warning means action must be taken.

It is essential to follow advice from authorities under all circumstances and expect significant disruption. Only take journeys if absolutely essential and carry emergency food and clothing. Red warnings mean there could be widespread flooding of property and severe disruption to travel. There may be some loss of utilities (gas, electricity and water). There may be possible risk to life and the advice of the emergency services needs to be followed.

Check the latest forecast for your area on our severe weather page.

You can also sign up to our severe weather RSS feed or severe weather twitter account for your local area.

For more information on our severe weather warnings service, watch our video guide:

The Environment Agency’s Floodline 0845 988 1188 is available 24 hours a day for flood advice or you can see the latest flood warnings on our website.

For more detailed travel information check the Highways Agency’s website.