Spring on track to be coldest for 30 years

Early figures from the Met Office show spring (March, April and May) 2013 is on course to be the coldest in the UK since 1979.

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

	UK	England	Wales	Scotland	NI
Mean temp (° C)	6.1	6.8	6.2	4.7	6.3
Diff from avg (° C)	-1.7	-1.7	-1.8	-1.6	-1.5
Coldest since:	1979	1962	1979	1979	1986
Rainfall (mm)	214	158	246	292	240
% of avg	89.8	87.3	84.3	92.3	99

*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?

Met Office keeping a close eye on space weather

The Met Office will be keeping a close eye on the Sun over the coming days after a recent surge in its activity.

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.

April weather summary video and your photos

Following on from the second coldest March on record, April was another cool month, with  temperatures below average everywhere. The provisional UK mean temperature was 6.3 °C, which is 1.1 °C below the 1981-2010 average, very similar to 2012 but otherwise the coldest April for the UK since 1989. Forecaster Helen talks through the weather we’ve seen this month in our 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)

Visible satellite image of triple lows over the UK

This visible satellite and rainfall radar image shows the three areas of low pressure affecting the UK today.

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.

The jet stream and why it’s too early to write-off summer

There have been one or two stories in the press today saying we’re in for another washout summer, which would rightly inspire collective misery across the country.

However, it’s a far too early to be writing off any chance of a decent summer season – after all, it doesn’t officially start (for us meteorologists) for more than two weeks (on 1 June).

It appears the news stories are borne out of the current position of the jet stream, a band of fast moving westerly winds high up in the atmosphere. But why is this important?

A quick Jet stream explainer

The jet stream tends to guide the generally wet and windy weather systems which come in off the Atlantic. So, if it’s over us or just to the south, we tend to get a lot of wet and windy weather – which is what we expect through winter.

If the jet is to the north of us, it guides that changeable weather to the north to give us more settled conditions – which is what we expect in the summer.

(You can read a bit more about the jet stream, how it impacted our weather last year, and any potential connections to climate change in a blog story we wrote last year).

What’s going on now?

Right now the jet stream is sitting to the south of the country and it is influencing the unsettled weather we are seeing at the moment.

Forecast chart showing position of the jet stream at midday on 13 May 2013

It’s fair to say that this is roughly the position it was in for extended periods during the exceptionally wet weather that we saw last year, particularly in June.

Crucially, however, the jet stream does move around quite a bit and it can change its track significantly in just a few days. So the current position of the jet stream does not mean that it’s stuck in that position.

Looking ahead

Much like our weather, it’s a huge challenge to predict the exact track of the jet stream more than five or six days ahead, so there’s still a great deal to play for in the outlook for our summer.

In short, it’s far too early to write-off summer 2013 based on the current position of the jet stream.

To get the best information on what to expect you can see the latest detailed forecasts out to 5-days on our website, as well as a general view of what we expect out to 30 days.

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

April drier and colder than average

After the wettest April on record in 2012, provisional full-month Met Office figures show this April has been slightly drier than average in the UK.

Rainfall throughout the UK was 64 mm this year, compared to the 1981-2010 average of 72.7 mm. That’s considerably less than the 128 mm we saw last year.

There were big regional differences in April rainfall this year. Scotland saw 121.2 mm of rain which is above the 91.1 mm average and Northern Ireland saw 75.2mm, almost spot on the 75.0 mm average.

However, both England and Wales saw well below average rainfall. Wales had 50.3mm, compared to an average of 89.3mm, and England saw 30.4mm, compared to an average of 58.7 mm.

The month was characterised by generally cold and dry weather, following on from the theme set in March. Despite this, April registered as only slightly colder than average with a mean UK temperature of 6.3 °C, which is 1.1 °C below the 7.4 °C long-term average.

This is the same mean temperature as recorded in April 2012. To find a colder April than the last two years, you have to go back to 1989 – which saw a mean temperature of 5.5 °C.

Scotland saw the coldest temperatures compared to country specific averages, with a mean temperature of 4.8 °C, which is 1.3 °C below average – and is the same temperature as recorded in 1998.

The warmest day of the month was 25 April at Faversham in Kent when the temperature recorded was 23.1°C.

In terms of sunshine, Scotland was sunnier than the rest of the UK with hours of sunshine totalling 170.9, followed by Northern Ireland with 168.0, England at 167.7 and Wales at 162.7 hours.

This compares with only 127.9 hours of sunshine in April last year throughout the UK. The sunniest April in the last 10 years was 2007 with 203.5 hours.

	Mean Temperature		Sunshine hours		Rainfall
Apr-13	Actual	Diff to Avg	Actual	Diff to Avg	Actual	Diff to Avg
	degC	degC	hours	%	mm	%
UK	6.3	-1.1	168.4	114	64	88
England	7.2	-0.9	167.7	108	30.4	52
Wales	6.4	-1.2	162.7	105	50.3	56
Scotland	4.8	-1.3	170.9	127	121.2	133
N Ireland	6.5	-1.1	168	115	75.2	100

Warm but unsettled weekend ahead as cold eases grip on UK

The UK is set to see some warmer temperatures this weekend as the colder than average weather seen so far this April eases its grip.

Temperatures have been steadily climbing since the exceptionally cold weather towards the start of the month, with today through to Friday set to see double-digit figures for many places.

On Saturday temperatures will be generally between 11 and 13 °C, feeling much milder than recent days. However, the weather will be wet, fairly windy and unsettled for many parts – with the best of any drier and brighter weather in the south and east.

Forecast chart for midday Saturday shows low pressure moving in from the Atlantic to bring mild but wet and windy weather for most of the country. High pressure still dominates in the south and east, bringing the best of any drier and brighter weather.

Warmest day of the year so far

Sunday looks set to be the warmest day of 2013 so far, with temperatures expected to be widely in the mid-teens Celsius. While the weather will be slightly more settled than Saturday, many places will see cloudy and breezy conditions with a risk of some light showers.

Once again the south and east will see the best of the weather, with drier and brighter conditions and temperatures of 15-18 °C – with a possibility that some isolated spots could reach around 20 °C.

Leading in to next week temperatures look set to cool slightly, but remain around average for the time of year.

Jet stream shift brings milder weather

The reason for the shift away from the colder weather is the re-alignment of the jet stream, a band of fast moving westerly winds high up in the atmosphere which tends to guide Atlantic weather systems. It’s these weather systems that bring us the mild and unsettled weather we normally expect at this time of year.

During the prolonged cold conditions the jet stream tracked far to the south of the UK, guiding those mild weather systems towards the Mediterranean. The UK, meanwhile, saw an easterly flow – bringing in cold conditions from the cold winter climes of north-east Europe.

Now the jet stream has started to shift its track, moving north to a position more in line with what we’d expect at this time of year. This means we expect to see milder, but also more unsettled weather coming in from the Atlantic over the coming week or so.

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

Cold Weather Alert Service extended to help support

With cold weather forecast across the UK as we head through the Easter weekend and into the start of April, the Cold Weather Alert Service, which usually finishes at the end of March, has been extended for an additional two weeks.

The Cold Weather Plan, which has run successfully since 2011, has been developed by the Department of Health, Met Office and Health Protection Agency, and supported by AgeUK.

The purpose of the Cold Weather Plan is to help raise awareness of the dangers of cold weather on health with both the general public and professionals alike. It spells out what preparations both individuals and organisations could make to reduce health risks and includes specific measures to protect at-risk groups.

The Cold Weather Plan has been supported again this winter by the Met Office Cold Weather Alert Service, which notifies frontline staff across the health, social care, community and voluntary sectors, and AgeUK, as well as the general public across England, when cold weather could impact on our health.

The continued period of cold weather has brought substantial media focus. By extending the service we are ensuring that accurate and reliable forecasts and alerts are sent to frontline staff and carers in our health services. This will help them to look after those who are more vulnerable and ensure that they stay well and healthy during this prolonged spell of cold weather.

You can keep up to date with the latest forecasts from the Met Office on our website.

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.