Heaviest rain moves away after wet day in South West

It has been another very wet day across parts of the UK, resulting in widespread flooding across parts of the south west of England. Severe Flood Warnings were issued by the Environment Agency for several rivers through the day. This followed the Met Office issuing a Red Severe Weather Warning on Friday evening  for heavy rain in parts of south west England.

The heavy rain that had affected parts of the north Midland and northern England on Friday pushed further north bringing heavy rain to parts of the far north of England and southern and central Scotland.

The table below shows the amount of rain that fell between 7.00 pm on Friday and 4.00 pm on Saturday.

UK RAINFALL 06 July 7.00 pm – 07 July 4.00 pm
SITE NAME	AREA	RAINFALL        AMOUNT ( MM)
DUNKESWELL AERODROME	DEVON	56.2
ISLE OF PORTLAND	DORSET	52.6
NETTLECOMBE, BIRDS HILL	SOMERSET	46.8
EXETER AIRPORT	DEVON	44.8
EDINBURGH, ROYAL BOTANIC GARDEN	MIDLOTHIAN	42.8
LISCOMBE	SOMERSET	40
CHARTERHALL	BERWICKSHIRE	38.8
CAMBORNE	CORNWALL	37.8
PLYMOUTH, MOUNTBATTEN	DEVON	36.6
HURN	DORSET	35.6
WIGHT: ST CATHERINES POINT	ISLE OF WIGHT	34.4
ST ATHAN	S. GLAMORGAN	33.8
CULDROSE	CORNWALL	31.8
SWANAGE	DORSET	30
CARDINHAM, BODMIN	CORNWALL	29.6
YEOVILTON	SOMERSET	28.4
STORMONT CASTLE	DOWN	26
NORTH WYKE	DEVON	24.6
SAUGHALL	AYRSHIRE	23.8
HELENS BAY	DOWN	23.8

 

The forecast for the rest of tonight is for outbreaks of rain to continue in both far northern and southeastern parts of the UK. Showers in many other areas should die away, with western parts in particular becoming largely dry. Some eastern and central parts may continue to see isolated heavy showers. The forecast for the rest of tonight is for outbreaks of rain to continue in both far northern and southeastern parts of the UK. Showers in many other areas should die away, with western parts in particular becoming largely dry. Some eastern and central parts may continue to see isolated heavy showers.

Updated rainfall totals: over a month’s worth of rain falls in south east

An area of low pressure across south-eastern areas of Britain has given some persistent and heavy rain over the last couple of days, with parts of Surrey and Sussex seeing more than a month’s worth of rainfall in 36 hours.

Rain is still currently falling in parts of the South East and heavy showers are forecast for south west England and Wales. The Met Office currently has severe weather warnings in place for south west England, Wales and south east England for further heavy rain.

The table below shows rainfall totals from 7 pm Sunday evening until 7 am this morning. Wiggonholt in West Sussex has seen 72 mm of rain, almost one and a half times its monthly average for June of 52.9 mm.

Site name	Area	Precipitation amount (mm)
Wiggonholt	West Sussex	72
Thorney Island	West Sussex	68.6
Shoreham Airport	West Sussex	67.8
Swanage	Dorset	55.2
Charlwood	Surrey	55.2
Odiham	Hampshire	55
Otterbourne W Wks	Hampshire	53
Kenley Airfield	Greater London	49.2
Wisley	Surrey	47
Middle Wallop	Hampshire	45.8
London, St James’s Park	Greater London	44.6
Rothamsted	Hertfordshire	44.4
South Farnborough	Hampshire	44
Hampstead	Greater London	43.2
Alice Holt Lodge	Hampshire	40.8
Boscombe Down	Wiltshire	40.4
High Wycombe, Hqair	Buckinghamshire	37.6
Goudhurst	Kent	37.4
Larkhil	Wiltshire	36.8
Woburn	Bedfordshire	36.2
Kew Gardens	Greater London	36.2
Benson	Oxfordshire	35.8

The jet stream is partly to blame for our unsettled conditions at the moment. It is currently flowing to the south of the UK, allowing a series of low pressure systems to spread in from the Atlantic.

There are many factors which can impact the notoriously changeable weather in the UK, so no single one on its own can be said to be fully responsible. However, it is possible to isolate contributing factors and, in this case, one of those is the northern hemisphere jet stream. This is a narrow band of fast flowing westerly winds (ie blowing from west to east) in the high atmosphere. This band moves around and also changes its track, from a fairly straight line to something more closely resembling a meandering river. Its position can, and does impact weather in the UK and other parts of the northern hemisphere.

What’s bringing the cold weather to Europe and the UK?

The current cold weather across Europe is in sharp contrast to the mild, wet and windy conditions across much of Europe through December and January. The cause of the cold conditions is the development of a large ‘blocking’ anticyclone over Scandinavia and north-western Russia. Easterly winds on the southern edge of this system has transported cold continental air westwards, displacing the more usual mild westerly influence from the Atlantic Ocean all the way to the British Isles.

Global land and sea surface temperature anomalies for 1-5 February 2012

A ‘blocking anticyclone’ can be thought of being like a very large boulder in a stream. This boulder acts like a dam, stopping the flow of the stream.  In this instance a block stops the more normal westerly flow that brings milder conditions, allowing colder conditions to win out from the east.

The origin and persistence of blocks has been a subject of much research, and unfortunately we are still not absolutely clear on why we see blocks form. What we do know though is that the origins of this large blocked pattern across Europe can be traced back to the appearance of two individual regions of mid-latitude blocking over central Russia and the Bering Sea in mid January. Over the next two weeks, these two regions merged together to form the ’block’ we see now.

The appearance of significant blocking after a long absence is reflected in the strong decline of the Arctic Oscillation (AO) index, which effectively describes a state in the atmosphere where the flow of westerly winds is either stronger or weaker than usual in the northern hemisphere. It is currently in its negative phase, meaning the westerly flow is less strong than normal. The switch to a negative AO was seen in late January and highlights the dramatic change from generally strong westerly flow to the much less westerly or even easterly blocked state.   

Despite the general unpredictability of blocking patterns, there were potential signs of an increased risk of a significant cold weather several weeks ago when the high altitude winds began to weaken in longer-range forecasts. We now understand that there is a clear link between the weakening of these high altitude winds and the surface weather that operates on monthly timescales and in situations like this it can provide a ‘window of opportunity’ for monthly forecasts to warn of increased risk. Based on this understanding, the Met Office 16 to 30 day forecast has reflected the increasing risk of cold conditions since mid January.

Met Office Hadley Centre scientists have investigated and demonstrated a clear stratospheric influence on surface climate during these events, with easterly winds burrowing down through the atmosphere to affect the jet stream and surface climate. The result is a switch from mild westerly Atlantic flow over Europe to easterly winds with an increased risk of cold extremes.

Weakening of the jet stream in the Stratosphere can allow easterly winds to move down through the atmosphere to give cold easterly winds at the surface. This can result in cold and snowy weather across the UK.

A similar situation occurred at this time of year in 2009 when we had significant snowfall across the UK and other parts of Europe, following a strong breakdown of the high altitude jet. Although only some cold winter spells can be predicted in this way, other recent winters such as 2006 and 2010 have also shown clear examples of the effect.

Last night’s temperatures: A night of contrast

Freezing temperatures combined with rain in the north to bring treacherous ice conditions across parts of southern Scotland, northern England and north east Wales last night and this morning as temperatures fell well below freezing across Wales, England and southern Scotland.

However, there was a marked contrast further to the north and west. Milder Atlantic air across northern Scotland and Northern Ireland to the north and west of the rainband straddling the UK resulted in a relatively mild night for mid February.

The coldest place in the UK was Linton on Ouse in North Yorkshire, recording a low of -9.6 °C, whilst at the other end of the scale, Aultbea in Ross and Cromarty, saw temperatures fall no lower than 7.6 °C.

The two tables below show the coldest and mildest spots in the UK last night.

 Coldest places in the UK overnight 8 – 9 February 2012

SITE NAME	MIN TEMP (celsius)	AREA
LINTON ON OUSE	-9.6	NORTH YORKSHIRE
TOPCLIFFE	-8.6	NORTH YORKSHIRE
BALA	-7.3	GWYNEDD
PATELEY BRIDGE	-7.0	NORTH YORKSHIRE
SENNYBRIDGE	-6.9	POWYS
WOODFORD	-6.7	CHESHIRE
RAVENSWORTH	-6.7	NORTH YORKSHIRE
CHURCH FENTON	-6.7	NORTH YORKSHIRE
DISHFORTH AIRFIELD	-6.7	NORTH YORKSHIRE
OKEHAMPTON	-6.5	DEVON
LEEMING	-6.4	NORTH YORKSHIRE
TREDEGAR	-6.2	GWENT
BINGLEY	-6.1	WEST YORKSHIRE
GOGERDDAN	-6.1	DYFED
EMLEY MOOR	-6.0	WEST YORKSHIRE
PRESTON MONTFORD	-6.0	SHROPSHIRE
BRADFORD	-5.8	WEST YORKSHIRE
ROCHDALE	-5.7	GREATER MANCHESTER
ALBEMARLE	-5.5	NORTHUMBERLAND
REDESDALE CAMP	-5.4	NORTHUMBERLAND
PENNERLEY	-5.4	SHROPSHIRE
LLYSDINAM	-5.3	POWYS
BRAMHAM	-5.3	WEST YORKSHIRE
BAINBRIDGE	-5.1	NORTH YORKSHIRE
CAPEL CURIG	-5.0	GWYNEDD

Mildest places in the UK overnight  8 – 9 February 2012

SITE NAME	MIN TEMP (celsius)	AREA
AULTBEA	7.6	ROSS & CROMARTY
SOUTH UIST RANGE	6.8	WESTERN ISLES
STORNOWAY AIRPORT	6.7	WESTERN ISLES
KINLOCHEWE	6.6	ROSS & CROMARTY
TIREE	6.3	ARGYLL
ALTNAHARRA	6	SUTHERLAND
BALLYKELLY	5.8	LONDONDERRY
SKYE: LUSA	5.6	WESTERN ISLES
ACHNAGART	5.5	ROSS & CROMARTY
ISLAY: PORT ELLEN	5.5	ARGYLL
MAGILLIGAN	5.5	LONDONDERRY
BALTASOUND	5.3	SHETLAND
FAIR ISLE	5.3	SHETLAND
MURLOUGH	5.3	DOWN
RESALLACH	5.2	SUTHERLAND
MACHRIHANISH	5.2	ARGYLL
CASTLEDERG	5.2	TYRONE
KILLOWEN	5.1	DOWN
BALLYWATTICOCK	5	DOWN
ST ANGELO	4.8	FERMANAGH
KIRKWALL	4.8	ORKNEY
LOCH GLASCARNOCH	4.7	ROSS & CROMARTY
WICK AIRPORT	4.7	CAITHNESS
HELENS BAY	4.6	DOWN
STORMONT CASTLE	4.6	DOWN

The battle between the milder Atlantic air and the very cold air in the southeast continues across the UK, bringing the risk of snow across parts of the country later today and into Friday. Whilst there is uncertainty about where the heaviest and most persistent snow will fall, accumulations of up to 10cm are possible in the worst affected regions. As a result Met Office warnings have been issued and there could be some disruption to travel.

The Met Office is working closely with government departments, contingency planners and transport agencies to make sure they have the best advice available to help them prepare for possible weather impacts.

Snow brings disruption in the east as ice becomes hazard into next week

Credit: Marco Anderson

As forecast, an Atlantic weather front pushed across the UK through yesterday and overnight bringing snowfall to many parts of the UK. As expected the worst of the conditions were across the east of the UK, where the cold air from the continent was able to hold on, leading to significant snowfall, especially across South East England, East Anglia, Lincolnshire, parts of the Midlands, Yorkshire, the North East and the southern uplands of Scotland.

Further west, although there was some snow for a time, the milder air, associated with the weather front soon turned the snow to rain, leaving a grey rather than a white start to Sunday.

As the snow and rain moved away, skies cleared allowing it to turn cold again with widespread ice in many conditions. The Met Office still have an Amber warning for icy roads in force at the moment valid until midday today. Overnight lows got to -9.8C at Bramham, -8.9C at Church Fenton, -8.4C at Topcliffe, Dishforth and Leeming, -7.3C at Church Fenton. -7.2C at Linton-on-Ouse and -6.2C at Ravensworth.

The table below shows snow depths recorded at 9 am this morning.

Location	Snow Depth ( CM)
Church Fenton	15
Wattisham	15
Marham	14
Conningsby	12
Cranwell	12
Leek, Thorncliffe	11
Herstmonceux	11
Northolt	10
Bingley	10
High Wycombe	9
Wittering	9
Eskdalemuir	8
Waddington	8
Coleshill	7
Heathrow	7
Nottingham, Watnall	7
Charlwood	6
Leconfield	6
Brize Norton	4
Woodford	4
Leeming	4
Loftus	4
Benson	3
Odiham	3
Albemarle	3
Odiham	3
Larkhill	3
Sennybridge	3
Andrewsfield	2
Hereford, Credenhill	2
Middle Wallop	2
Shawbury	1
Manston	1

The band of snow has now cleared the far southeast of England and for the rest of the day it will remain largely dry, but cold in the east, Further west it will turn cloudier with some outbreaks of rain, with some sleet or snow on higher ground. Overnight, cloud and a little rain will slowly spread to many places, although eastern Scotland will probably remain dry. Cold and foggy, especially in areas with lying snow and frosty in the east.

Heading into next week there is only a little snow in the forecast at the moment. Monday will be rather cold with ice likely to be a hazard especially in the southeast. It will then be generally cloudy with only occasional brighter intervals. Patchy rain will affect many areas, this mainly light. It will stay very cold in the east and southeast, but will be less cold elsewhere.

A busy year for the Met Office in 2011

It has been another very busy year for us here at the Met Office as we have helped the UK manage the risks of severe weather, supported the world in the aftermath of natural disasters, continued our support of the UK economy and celebrated successes.

January

As the big freeze of December 2010 weakened its grip on the UK our forecasters focused on heavy rain and the risk of flooding in Cumbria in mid January. The Met Office, working with the Environment Agency, provided guidance and warnings of the severe weather and its impacts from the joint Flood Forecasting Centre based at the Met Office in Exeter.

February

The Met Office forecast the most likely track of  Tropical Cyclone Yasi as it headed for Queensland in Australia, keeping the Foreign and Commonwealth Office and other National Meteorological Services around in the world informed.

Our first award of the year was won by our Ocean Scientists who were awarded the Denny Medal for the best research paper of 2010 by the Journal of Operational Oceanography.

March

The Met Office used its global forecasting capability to support UK Government and relief charities in the aftermath of the earthquake and tsunami that devastated parts of Japan. Closer to home, the Met Office launched the Scotland Flood Forecasting Service in partnership with the Scottish Environment Protection Agency. This is a new service providing emergency responders and the Scottish Government with the tools and forecasts to better prepare for and respond to floods.

We also launched improvements to the National Severe Weather Warning Service that brought clearer, more targeted warnings based on the likely impacts severe weather can bring.

April

High pressure dominated through the month bringing fine weather and warm temperatures.  April 2011 became the warmest on record for the UK with temperatures some 3.7 °C above the average for the month.

By the end of the month the world’s attention was focused on Westminster Abbey as HRH Prince William married Catherine Middleton. Our forecast of sunny spells and a 10% chance of a shower through the morning was spot on as the centre of London stayed dry for the wedding while showers ran to the north.

May

Toward the end of May the Met Office Volcanic Ash Advisory Centre (VAAC) was called into action as the Grimsvötn volcano on Iceland erupted.  We provided forecast guidance to support decision-making by the Civil Aviation Authority and airline operators on whether aircraft can fly safely.

US President Barack Obama, on a visit to the UK, joined Prime Minister David Cameron to welcome the growing partnership between the Met Office and the U.S. National Oceanic and Atmospheric Administration’s (NOAA) in working toward the delivery of space weather alerts.

June

June saw the launch of the Met Office Weather Observations Website. Supported by the Department for Education and the Royal Meteorological Society the website provides a platform for sharing current weather observations from across the world. After just six months more than 12.5 million observations had been submitted.

Late June saw the first Heat-Health alert of the summer as temperatures reached 33.1 deg C in Gravesend in Kent – the warmest summer day in over 5 years. This didn’t last, however, as the summer was relatively cool with average temperatures of 13.7 deg C. This didn’t stop key events from going ahead, with the Met Office providing accurate forecasts for the organisers of Wimbledon and The Open Championships.

July

In July we saw responsibility for the Met Office move to the Department for Business Innovation and Skills (BIS). The move provides us with the opportunity to create, together with partners, a centre of excellence for scientific delivery in support of UK economic growth.

This month the Met Office became one of only a handful of organisations to achieve the prestigious Wildlife Trust Biodiversity Benchmark Award for protecting and promoting biodiversity.

August

The Met Office celebrated 150 years of forecasting for the nation on the 1^st of August as it marked the anniversary of the first ever weather forecast appearing in print. This gave us, and the media, a chance to reflect on the huge progress made in meteorology and the Met Office’s role as a pioneer at the forefront weather science.

September

A research project investigating how people respond to probabilities in weather forecasts became the largest of its kind ever carried out after thousands of people logged on to play an online game. This is part of our ongoing work to look at ways to help people make better use of our forecasts.

After tracking across the Atlantic, a post tropical storm that had formerly been Hurricane Katia arrived on UK shores bringing some very strong winds. This was the most powerful ex-hurricane to reach the UK since Hurricane Lili in 1996. Accurate forecasts from the Met Office and frequent updates on the progress of the storm helped people in affected areas to prepare and stay safe.

October

The UK set a new record temperature for the month of October when Gravesend recorded 29.9 °C on the 1st October. This followed several days of exceptionally warm weather. Wales also secured a new October record when Hawarden reached 28.2 °C on the same day.

November

The Cold Weather Alert Service was launched to provide public alerts to help vulnerable groups keep well during winter. We also launched a number of products including a new route based forecast service for winter road maintenance that gives road operatives the opportunity to grit routes selectively and Weather Windows – designed to help airports manage resources around weather-related demands.

The Met Office also secured three awards. Our Atmospheric Dispersion Group won the Science, Engineering & Technology Award at the prestigious Civil Service Awards for their work during the volcanic eruptions and Japan nuclear incidents. Dr Adam Scaife, one of our leading scientists won the Lloyd’s Science of Risk prize for research which has shed new light on how UV radiation from the Sun can influence weather over Europe.  We also garnered the Best Use of Social Media award in the public sector at the Computer Weekly’s Social Media Awards 2011.

December

December saw the publication of the results of a major new scientific assessment of climate change, highlighting the changes the world has already seen and the impacts it could face if global temperature changes are not limited. The assessment, commissioned by Chris Huhne – the UK’s Secretary of State for Energy and Climate Change – and led by the Met Office Hadley Centre, studied 24 different countries, to support policy decisions on climate change.

What’s behind the stormy weather so far this winter?

So far this winter the UK has seen some very strong winds associated with a series of Atlantic storms. This has included some near-record strength gusts of wind in places, with Scotland particularly badly affected.

On 8 December a gust of 165mph was recorded at Cairngorm Summit (1245m above sea level) during the first of the winter storms – that gust was just 8mph off the strongest ever recorded in the UK (set at the same spot in 1986). Even at low level there were strong winds, with 105mph at Tulloch Bridge in Highland.

Another powerful storm affected Scotland on 28 December, and today we saw another – this time notching up winds of around 100mph in parts of Scotland. The 102mph gust at Blackford Hill in Edinburgh is the third highest recorded at that station, and the strongest since 1998.

So has this winter been particularly stormy? We actually expect stormy weather in the UK at this time of year. In normal circumstances, low pressure systems develop over the Atlantic and track from west to east – eventually moving over the UK bringing strong winds and often heavy rain with them. This year we’ve seen nothing to disrupt that westerly flow, leading to the succession of low pressures systems we’ve seen so far.

While the general weather pattern is what we expect to see at this time of year, the strength of the storms and winds has been unusual. This is down to the jet stream – the high altitude winds which blow from west to east across the Atlantic and brings us our traditional changeable weather.

Over the past few weeks the jet stream has occasionally been particularly strong and some of the low pressure systems have interacted with that as they have tracked over the Atlantic, boosting their strength. This has led some of the lows to develop into powerful storms which have brought very strong winds to the UK.

The weather is set to remain changeable for the rest of this week, and beyond that it’s not possible to say whether we will see any more particularly strong storms this winter. However, we’ll continue to keep everyone up to date with the latest outlook in our forecasts and warnings.

Met Office in the Media – 25 November 2011

There are a couple of interesting articles about the weather in today’s press.

First of all, in the Daily Telegraph, a contradictory story with a headline which claims we shouldn’t “expect a big freeze this Christmas“. The introduction goes on to say the Met Office is predicting “unseasonable weather” – when actually, we are predicting normal weather for the time of year.

The Met Office quote further down the article gives a more accurate picture: “Last December saw a very prolonged period with wave after wave of cold spells and snow, ice and sub-zero temperatures. Rather than that, it looks like we’re in for a mixed, unsettled December this year, with some cold spells but also milder spells.”

To clarify, last year we had the coldest December in more than 100 years. The Met Office forecast for 30 days ahead, which still does not cover the whole month of December, suggests that we are unlikely to see a repeat of the persistent and extreme cold and snowy conditions that we saw last year.

Instead the current Met Office forecast is for much more normal conditions for the time of year, with periods of wind and rain interspersed with colder spells bringing some overnight frost and a chance of snow – mostly over the higher ground in Scotland. As always we will keep the British public warned and informed when severe weather is expected to affect the UK through our 5 day forecasts and our National Severe Weather Warning Service.

There’s also an article in the Daily Express which suggests Scotland will be “blanketed” with snow. There has been some snowfall in Scotland overnight and this morning, but – as forecast by the Met Office – this has generally been on high ground above 400m. We are expecting further snowfalls over the next few days, but again only on the high ground in Scotland.

 

Met Office launches changes to the National Severe Weather Warning Service

The Met Office has launched improvements to the National Severe Weather Warning Service that will bring clearer, more targeted warnings based on the likely impacts that severe weather can bring.

The new Alerts and Warnings, issued by the Met Office National Severe Weather Warning Service will:

• Be easier to understand – using clear language, making the information less technical.
• Be impact based – warnings will be based on the impacts of expected weather conditions in the area likely to be affected.
• Use consistent language – The use of Alerts and Warnings is consistent with that used by other organisations such as in SEPA and EA flood warnings.
• Improve the display of information – using clear, concise and distinct graphics on the Met Office website.

Patricia Boyle, Public Weather Service Manager at the Met Office said: “Severe weather can have differing impacts depending on time and location. For example heavy rain in one part of the country may have a greater impact than in another or severe gales may have a greater impact in autumn than in winter.

“Taking this information into account should lead to fewer weather warnings being issued whilst making them more relevant to the public and emergency services.”

Finally, the Met Office will be changing the way warnings are displayed on its website to make it easier to find the information that is relevant to users’ particular needs. Users will be able to see at a glance the basic information they are interested in and then, if they wish, drill down to find more detail.

These latest improvements follow an extensive 18 month consultation with local councils, police and fire services as well as the public. It is hoped they will lead to a greater awareness of severe weather and its potential impacts, helping the public to be prepared and take action if necessary.

Nick Baldwin, Chairman of the Public Weather Service Customer Group said: “The Met Office provides extremely accurate short-term forecasts and warnings, and the Met Office’s severe weather warnings are highly trusted by the British people.

“Research from the Met Office has shown that during the snow in December last year, 80% of people surveyed said they were aware of the warning and 95% of those found the warning useful.”

The improvements will continue to deliver critical, safety of life information to those that need to know it, when they need to know it; keeping the public and emergency services informed of high impact weather so that they can take action to keep safe and well.

Find out more about the new National Severe Weather Warning Service