Storm Imogen brings gales to southern areas of Britain

7 02 2016

An area of low pressure, which will bring some very strong winds across southern parts of the UK as it moves eastwards on Monday, has been named as Storm Imogen.

Gusts of 60-70 mph are possible in southern England and parts of south Wales with 80 mph gusts possible in exposed coastal districts. Some very large waves are also likely along some coasts, especially along the north coast of Cornwall and Devon.

The Met Office has today (Sunday 7 February) issued an Amber “be prepared” National Severe Weather Warning for for wind for Storm Imogen which is valid from 3 am until 6 pm on Monday.  There is also a larger Yellow “be aware” Severe Weather Warning for wind valid from 3 am to 6 pm on Monday.

Surface Pressure Chart Monday 8 Februrary

Surface Pressure Chart Monday 8 Februrary

There remains some uncertainty just how far north and east the strongest of the winds will extend. However, you can keep up to date with the latest for your area using our forecast pages and by checking the Severe weather warnings.

Storm Imogen follows Storm Henry, which passed close to the north of Scotland through Monday 1 February 2016 into Tuesday 2 Feb.

Winds are expected to ease through Tuesday leading to a short drier, quieter and colder interlude for many on Wednesday before more wind and rain follows later in the week.





Storm Henry forecast to bring severe gales in places on Monday

30 01 2016

A rapidly deepening area of low pressure pushing quickly across the Atlantic and expected to run close to the north of Scotland through Monday and into Tuesday has been named as Storm Henry. Keep up to date with the latest for your area using our forecast pages.

Forecast chart for Monday 1 February 2016

Forecast chart for Monday 1 February 2016

The Met Office issued an Amber National Severe Weather Warning for Storm Henry on Saturday morning. The Amber warning is valid from 3pm on Monday afternoon until 3am on Tuesday morning. Storm Henry closely follows Storm Gertrude, which tracked away from Shetland on Friday night.

The weather is expected to remain unsettled over the coming days with the prospect of further deep Atlantic depressions bringing spells of wind, rain and snow at times. You can stay up to date with the latest forecast for your area using our UK forecast pages and Severe weather warnings. You can also view our latest forecast Videos

During Saturday it will remain very windy in the north of the UK with severe gales across Scotland. These strong winds will be combined with frequent sleet or snow showers, leading to some drifting and blizzard conditions, especially over high ground, but even at low levels for a time. Severe weather warnings for wind and snow have been issued for Scotland, Northern Ireland, Wales and northern England to the Midlands.

For Saturday night snow showers will remain in the north and west and there will be some icy patches.

During Sunday milder, cloudier and wetter conditions will spread slowly northeastwards across the UK, but only slowly with northern, eastern and some central regions staying cold for much of the day and these wetter conditions preceded by some transient snow over higher ground in northern, western and central Britain..

On Monday the vigorous low pressure system – named as Storm Henry –will be approaching the UK from the Atlantic. Currently, this system is expected to pass just to the north of Scotland, bringing very strong west or southwesterly winds across much of the UK. Gales or severe gales with heavy rain are expected across northwestern parts. These winds could bring disruption to transport as well as power supplies.

Dan Suri, Chief Operational Meteorologist said: “With several periods of severe weather forecast to affect the UK over the coming days, it’s a good idea to keep a close eye on the forecast and the National Severe Weather Warnings as the details of what areas are to be affected and when, are likely to change. Our forecast pages, Facebook and Twitter sites and our Weather App can all help you keep up to date with the weather so that you can plan ahead and be prepared.”





Another unusual January hurricane forms

14 01 2016

Just two days ago we reported how Pali had become a very unusual out-of-season hurricane in the North Pacific. This afternoon another unusual hurricane has formed – this time in the North Atlantic. The hurricane season for both these regions usually runs from about June to November.

Earlier in the week a non-tropical area of low pressure developed near Bermuda. This was a depression primarily driven by the clash of cold air from the north and warm air from the south, similar to the kind of depressions we experience in the UK. Strong winds were recorded on Bermuda as the depression tracked to the east. Then in the last two days the depression has started to develop a concentrated area of storm clouds near its centre to the extent that the National Hurricane Center declared it to be ‘Subtropical Storm Alex’. Being ‘subtropical’ is a hybrid state for storms which exhibit some, but not all the characteristics of a fully tropical storm. Alex became the first subtropical storm to develop in the North Atlantic in January since 1978.

In the last day Alex has continued to develop a strong central mass of storm clouds rotating around a small eye and the National Hurricane Center has now designated it as a full blown hurricane. Alex is the first North Atlantic hurricane to exist in the month of January since Alice in 1955 and the first to actually form in the month of January since 1938.

Hurricane Alex at 1315 UTC on 14 January 2016 Image courtesy of the US Naval Research Laboratory

Hurricane Alex at 1315 UTC on 14 January 2016                                                  Image courtesy of the US Naval Research Laboratory

 

Alex is currently situated about 1000 km to the west of the Canary Islands. It is expected to move northwards bringing stormy conditions to the Azores where hurricane warnings have been issued. Winds over 75 mph and 100 mm rain or more is possible. An area of high pressure is expected to develop over the UK this weekend which should keep Alex over the ocean and away from our shores. Alex is eventually expected to be absorbed into a larger depression in the Atlantic near the southern tip of Greenland on Sunday.

Official warnings for the tropical cyclones in the North Atlantic are produced by the US National Hurricane Center. 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. We also provide updates on current tropical storms via @metofficestorms on Twitter.

Hurricane Alex at 1330 UTC on 14 January 2016 Image courtesy of the US Naval Research Laboratory

Hurricane Alex at 1330 UTC on 14 January 2016





Reporting the weather across the UK

8 01 2016

December 2015 was the wettest calendar month for the UK in a series of monthly weather records stretching back to 1910. But why does the Met Office state 1910 when listing records, especially when some records existed well before that time?

Part of the answer is that the Met Office has a responsibility to collate weather records for the entire UK, the UK countries and historic counties.  The digital archive used to generate our UK analyses includes station observations back to 1853, but only since 1910 has there been a sufficiently dense network of stations to allow an analysis of the whole UK.

One station, the Oxford Radcliffe Observatory, which is managed by Oxford University School of Geography and the Environment – holds rainfall records back to 1767. This allows a greater understanding of the rainfall in Oxfordshire, but doesn’t allow greater comparison with England or the UK: vital when you are trying to provide a complete picture.

The England and Wales Precipitation (EWP) series stretches back to 1766. In recent times the EWP – a highly significant climate series – is based on records from around 100 stations, but the further you go back the fewer recording stations there were. This provides a good analysis of records for England and Wales, but doesn’t capture the remainder of the UK: Scotland and Northern Ireland. Additionally, it doesn’t take account of the thousands of recording stations which provide more detailed picture for the UK in more modern times.

Dr Mark McCarthy is the head of the Met Office’s National Climate Information Centre. Commenting on the results he said: “Although our UK dataset currently only stretches back to 1910 we are adding to it by digitising more of our extensive paper archives in order to extend these records further back in time. When we have done that it is possible that months like October 1903 may rival or even surpass some of the UK records set in December 2015.

“However for December 2015 we have a good picture  of the rainfall patterns across the UK such as the record breaking rainfall in: Cumbria, North Wales; eastern Dumfries and Galloway; and parts of the Cairngorms.”

December 2015 rainfall anomaly map

December 2015 rainfall anomaly map

“In fact, as our very high-resolution rainfall map in December 2015 shows, parts of England were close to average and some places actually recorded lower than average precipitation. Just like a digital photograph, greater resolution allows you to observe finer detail.  Therefore picking any one place or region may not be representative of the UK as a whole.”

Met Office national records are created using a method to interpolate observations from our network of stations onto a 5km by 5km grid covering the UK. The gridding method is a more sophisticated approach for analysing rainfall than simply taking an average of station data. However, because it also requires a denser network of stations it is not as long running a series as the EWP and some long running observing sites. The different datasets are therefore complementary and we use both to monitor our changing climate.

So, the UK’s national climate series – the records you will see quoted when the Met Office routinely releases statistics – is a comprehensive rainfall analysis covering the whole of the UK back to 1910 using all available observations. Other series including the EWP are also a vital part of our national climate monitoring and provide us with an even longer historical context for some parts of the UK.

Professor Adam Scaife is a climate scientist with the Met Office’s Hadley Centre. He said: “It’s clear that December 2015 was a very significant month for rainfall and was the highest since our records began in 1910.  We have been asked about the link between climate change and the rainfall in December 2015.

“With or without climate change there have always been exceptional spells of weather and there always will be. But climate change can add to the natural variations in our climate and it is this that increases the chance of record breaking weather and unprecedented extremes.  It is therefore vital that we monitor our weather and climate in as much detail as possible to assess and predict future weather extremes.”





What’s been happening to our weather?

31 12 2015

December 2015 will go down in meteorological history as one of the wettest – and warmest – on record. It will also be remembered for the devastating floods in Cumbria, Lancashire, Yorkshire and Scotland. The extensive flooding of homes and businesses, loss of electrical power, major damage to roads and bridges, and disruption to the rail network have caused great misery and incurred huge losses.

In this blog our Chief Scientist, Professor Dame Julia Slingo, discusses what factors may have influenced the record breaking weather we have seen in recent weeks.

As with all high-impact weather, the meteorological set-up was critical in defining the severity of these events. Throughout the month, the winds have come from the south or southwest, bringing both extreme warmth but also very high levels of moisture.

There has been a lot of debate whether this has been associated with El Nino – an intermittent warming of the equatorial Pacific Ocean which has been very strong this year – or whether this is a sign of a changing climate. The links to El Nino are certainly very clear in the set up of large waves (troughs and ridges) in the atmospheric circulation, which we expect to see in these events.

Latest monthly anomalies in sea surface temperatures showing the strong El Nino lying along the equator, the warmth of the north-east Pacific and western Atlantic and the colder than normal ocean temperatures of the northern North Atlantic

Latest monthly anomalies in sea surface temperatures showing the strong El Nino lying along the equator, the warmth of the north-east Pacific and western Atlantic and the colder than normal ocean temperatures of the northern North Atlantic

However, it does seem that this year the unusual warmth of the North East Pacific Ocean may have altered the position of these waves across North America and into the Atlantic sector, setting up the conditions for the devastating tornadoes in the US and for the southerly feed of moisture-laden air into the UK.

Circulation anomalies in the middle troposphere for 1-30 and 24-30 December

Circulation anomalies in the middle troposphere for 1-30 and 24-30 December, showing a persistent pattern of troughs (blue/purple) and ridges (green/orange) across the US, North Atlantic and into Europe. The trough over the western US set up the conditions for tornadoes along the confluence of cold air from the north with very warm air from the Gulf (see elevated sea temperatures above). The southerly airstream from Spain to the North Pole is established by the gradient between the trough over the North Atlantic and the ridge over Europe.

Storm Desmond in early December was associated with a strong west-south-westerly flow around the ridge over the eastern seaboard of the US, reaching far back across the Atlantic, as far as the Caribbean. With ocean temperatures well above normal in the southern part of the North Atlantic (see above) – possibly due to the much weaker than normal hurricane season this year associated with the current El Nino – the air was primed with more moisture than normal. This river of atmospheric moisture fed the storms that formed on a stronger than normal jet stream, and as the air impinged on the mountains of Cumbria, large quantities of rainfall were released.

Later in the month the southerly flow intensified, with a high pressure system to the east of the UK over continental Europe providing a block to the normal passage of the westerly jet. With colder than usual ocean temperatures over the northern part of the North Atlantic (see above), a strong temperature gradient formed which acted to strengthen the jet and set up the conditions for the formation of rapidly deepening cyclones, such as Storm Frank. These cyclones drew in warm, moist air from far south leading again to heavy rainfall and further flooding on already saturated ground. And the southerly winds on the eastern flank of Storm Frank, and strengthened by the high pressure to the east, enabled extremely warm air to penetrate, temporarily, the deep Arctic leading to very high temperatures.

Surface pressure chart 0001 30 December 2015

Surface pressure chart 0001 30 December 2015

The potential for December to be stormy and wet was picked up in the three-month outlook and is consistent with what we expect in early winter when there is a strong El Nino in place. However, early analysis suggests that the specific nature of this December’s extreme weather might be linked to the detailed structure of this El Nino, to the warmth of the north-east Pacific Ocean and to their combined effects on the atmospheric circulation.

As for whether climate change has played a role, we know that the overall warming of the oceans increases the moisture content of the atmosphere by around 6% for every 1°C warming. This extra moisture provides additional energy to the developing weather system, enabling even more moisture to be drawn in to the system, so that the overall enhancement of rainfall when the moisture-laden air impinges on the mountains of Wales, northern England and Scotland may be even more significant. So from basic physical understanding of weather systems it is entirely plausible that climate change has exacerbated what has been a period of very wet and stormy weather arising from natural variability.





Record breaking December rainfall

28 12 2015

This is has already been a record breaking month for rainfall in some parts of the UK, with exceptional amounts of rain falling onto already saturated ground.

The very wet Boxing Day in parts of north Wales and northwest England was well forecast five days in advance with Amber, be prepared, warnings in force from as early as last Wednesday.

In the event the highest rainfall amounts were around 100mm with peaks of 130mm in Lancashire and in excess of 200mm in Snowdonia and caused high impacts across parts of north Wales and northern England.

Map showing two day rainfall totals for Christmas Day and Boxing Day

Map showing two day rainfall totals for Christmas Day and Boxing Day

Here is a selection of the highest two day rainfall totals from Met Office observing sites for Christmas Day and Boxing Day:

48hr UK RAINFALL TOTALS 9am 25 DEC – 9am 27 DEC 2015
SITE AREA RAINFALL TOTAL (MM)
CAPEL CURIG GWYNEDD 210.6
STONYHURST LANCASHIRE 100
PATELEY BRIDGE, RAVENS NEST NORTH YORKSHIRE 97
BINGLEY WEST YORKSHIRE 93.6
BAINBRIDGE NORTH YORKSHIRE 89.8
BALA GWYNEDD 89.4
SHAP CUMBRIA 86.4
SPADEADAM CUMBRIA 79.4
PRESTON, MOOR PARK LANCASHIRE 73.2
MYERSCOUGH LANCASHIRE 72.4
BRADFORD WEST YORKSHIRE 69.4
ROCHDALE GREATER MANCHESTER 68.2
MORECAMBE LANCASHIRE 65.8
MONA ISLE OF ANGLESEY 63.6
KIELDER CASTLE NORTHUMBERLAND 61.2
DISHFORTH AIRFIELD NORTH YORKSHIRE 60.8

This wet spell has added to the heavy rainfall through the rest of the month to make December 2015 already the wettest on record in parts of the UK.

Here is a small selection of new December records from Met Office observing stations around the UK 9am 1 – 9am 28 December 2015:

Site Total (mm) 81-10 avg (mm) Previous record
Shap (Cumbria) 773.2 215.6 504.4mm in 2006
Keswick (Cumbria) 517.6 173 376.4mm in 2013
Warcop Range (Cumbria) 281.6 94.1 218.4mm in 2006
Stonyhurst (Lancashire) 331.4 141.6 319.3mm in 1951
Morecambe (Lancashire) 281.4 109.2 272mm in 1909
Bainbridge (North Yorkshire) 496.2 156.5 327.2mm in 2006
Bingley

(West Yorkshire)

241.4 114.3 247.2mm in 2006
Eskdalemuir (Dumfries and Galloway) 500 184.9 390.4mm in 2014
Glasgow Bishopton 311.4 145.6 294.8mm in 2006
Capel Curig (Conwy) 1012.2 308.9 612.8mm in 2006

This very unsettled and occasionally stormy spell was well signalled in our recent three month outlooks and is not unusual for this time of year, indeed this is when climatologically we would expect to have most of our storms.

Throughout this unsettled spell Met Office meteorologists and advisors are working round the clock with our partners to keep everyone up to date with the latest forecast information so they can plan and prepare for the expected weather.





December on track to be the mildest on record

24 12 2015

Mowing the lawn has been the reality for some so far this December, with unseasonably high temperatures. It looks as though the UK is on track to break the record for the warmest December since records began in 1910 and some areas have also seen their wettest.

The latest temperatures for December (1st to 22nd) reveal that the month so far has been far warmer than normal. Early provisional figures* reveal that the mean temperature for December in the UK has so far has been 8.1C, which is 4.2C above the long-term average for the month and well above the previous record of 6.9C set in 1934.

The December figure for England has so far been 9.5C, that’s 5.1C above the same long-term average and 2C above the record of 7.5C set in 1934, and the other UK nations have been similarly warm:

  • the mean temperature of 9.3C in Wales, higher than the previous post-1910 record of 7.5C set in 1934, and 4.8C above average
  • the mean temperature of 5.6°C in Scotland is 2.8C above average, but is so far slightly lower than the previous December record of 5.8C set in 1988
  • the mean temperature of 7.5°C in Northern Ireland is 3C higher than average, and marginally higher than the 1988 December record

Tim Legg of the Met Office National Climate Information Centre said: “With no sign of any significantly cold weather to come in the remaining 9 days of the month, we’re on track to break the warmest December record which was set back in 1934.”

Rainfall 1 - 22 Dec 2015

Rainfall 1 – 22 Dec 2015

MeanTemperature Dec 1 - 22, 2015

MeanTemperature Dec 1 – 22, 2015

 

 

 

 

 

 

 

 

 

 

Rainfall and sunshine figures so far confirm December has been dull and wet across most of the UK, with sunshine well down on the long-term average while precipitation (which of course has fallen mainly as rain) has been well above.  Some places have seen record breaking rainfall:

  • Cumberland 310.9mm rainfall 1 – 22nd Dec (previous record 248.2mm 2006),
  • Westmorland 474.4mm 1 – 22nd Dec (previous record 365.1mm 2006)
  • Dumfriesshire 314mm rainfall 1 – 22nd Dec (previous record 307.5mm 2013)
  • Carnarvonshire 441.3mm rainfall 1 – 22nd Dec (previous record 376.6mm 1965)
  • Roxburghshire 237.8mm rainfall 1 – 22nd Dec (previous record 219.7mm 2013)

 

EARLY mean temperature sunshine duration precipitation
1-22 Dec 2015 Act Anom Act Anom   Act Anom
  Deg C Deg C hours % mm %
UK 8.1 4.2 17.7 43 148.0 123
England 9.5 5.1 19.8 42 86.5 99
Wales 9.3 4.8 16.3 39 237.1 143
Scotland 5.6 2.8 14.1 46 229.1 140
N Ireland 7.5 3.0 20.7 56 130.4 114

 

You can find out what the rest of the year has been like on our climate pages.

*Data from the Met Office’s UK digitised records dating back to 1910.

Please note that these provisional figures, especially for rainfall and sunshine, are subject to revision. Anomalies are expressed relative to the 1981-2010 averaging period.





Mild start to December

16 12 2015

Looking at figures dating back to 1960 this has been the mildest start to December for Wales (8.7C), south west England (9.8C) and south east England (10C), and the 4th warmest for the UK as a whole (7.1C), with 1979, 2000 and 2006 being marginally milder.

Early provisional figures* (1-14 December) show the first half of December has been very mild across England and Wales with the maximum daily temperatures 3.2C above average for the UK as a whole.

However there has been a sharp north-south contrast at times with much colder air over Scotland and some frosts.  Elsewhere the humid south-westerly airflow means the weather has remained similar to last month: cloudy with very few clear nights, mild nights and very little sunshine for most areas.

Mean Temperature 1 -14 December 2015

Mean Temperature 1 -14 December 2015

 

The main talking point so far this month has been Storm Desmond, bringing record-breaking rainfall totals over the Lake District and a lot of rain over many northern areas.

Around 200% of the whole month’s normal rainfall has already fallen in a few places in the Pennines and the Lake District, it has also been wet in Snowdonia and parts of southern & central Scotland.  There has been near-normal rainfall across many other areas, and actually below average, for this point in the month, in parts of southern England.

EARLY mean temperature sunshine duration precipitation
1-14 Dec 2015 Act deg C Anom deg C   Act Hours Anom %   Act mm Anom %  
Regions            
UK 7.1 3.2 13.4 33 100.2 83
England 8.6 4.3 15.7 33 56.7 65
Wales 8.7 4.2 11.0 26 140.9 85
Scotland 4.2 1.4 10.4 34 161.6 99
N Ireland 6.1 1.6 13.1 35 99.0 87

 

Despite the mild start to winter following on from a mild autumn, it looks like 2015 will be an average year as far as weather is concerned.

This year’s damp and cool spring and summer mean that despite the current mild spell, the rainfall, temperature and sunshine statistics for the year as a whole are all hovering around average, with just 17 days left until the end of the year.

Indications are that the unsettled weather will continue through Christmas and into the new year. Showers or longer spells of rain are expected across all parts, with the heaviest and most persistent rain in the north and west, and the best of the drier conditions across south-east England.

We can expect gales at times, again especially in the north and west. Temperatures will be closer to average than of late, but still generally above, with any snowfall restricted to the high ground of Scotland and northern England.

Please note that these provisional figures, especially for rainfall and sunshine, are subject to revision. Anomalies are expressed relative to the 1981-2010 averaging period.

*Data from the Met Office’s UK digitised records dating back to 1910.





Climate change and weather caught in a media storm

11 12 2015

December so far has been characterised by intense media discussions about climate change and its relationship to weather.

Early in the month, the Met Office welcomed the BBC Trust report, which recognised there was a serious breach of their editorial guidelines and that the What’s the Point of the.. Met Office programme, aired in August, had failed to make clear that the Met Office’s underlying views on climate change science were supported by the majority of scientists.

Trustees considered audiences were not given sufficient information about prevailing scientific opinion to allow them to assess the position of the Met Office and the Met Office position on these criticisms was not adequately included in the programme.

In the wake of Storm Desmond, there have been further media comments about the relationship between climate change and weather.

On Monday, in a blog, we were very clear not to link the record-breaking rainfall with climate change.  This is what Professor Dame Julia Slingo, Met Office Chief Scientist has said: “It’s too early to say definitively whether climate change has made a contribution to the exceptional rainfall. We anticipated a wet, stormy start to winter in our three-month outlooks, associated with the strong El Niño and other factors.

“However, just as with the stormy winter of two years ago, all the evidence from fundamental physics, and our understanding of our weather systems, suggests there may be a link between climate change and record-breaking winter rainfall. Last month, we published a paper showing that for the same weather pattern, an extended period of extreme UK winter rainfall is now seven times more likely than in a world without human emissions of greenhouse gases.”

So, we have been clear: it’s not easy to link a single weather event to climate change, but last weekend’s record rainfall aligns with the pattern highlighted by our scientists. The Met Office expects an increase in heavy rainfall associated with climate change and this is an active area of research. A recent paper by the Met Office’s Mike Kendon highlights several key findings connected with rainfall records:

  • Since 2000 there have been almost 10 times as many wet records as dry records.
  • Remarkably, the period since 2010 accounts for more wet records than any other decade – even though this is only a five-year period. It also includes the winter of 2013/14: the wettest on record.

Guided by peer-reviewed science, the Met Office recognises the climate is changing, and with that comes an expectation that more records will be broken.





Did climate change have an impact on Storm Desmond?

7 12 2015

The exceptional rainfall in Cumbria over the past few days saw the fall of numerous records and has led many to ask whether it is linked to climate change. The records are based on digitised data going back to the 19th Century.

A gauge at Honister Pass recorded 341.4mm of rainfall in the 24-hours up to 1800 GMT on 5 December 2015, making for a new UK record for any 24-hour period. This beat the previous record of 316.4mm set in November 2009 at Seathwaite, also in Cumbria. A new 48-hour record (from 0900 to 0900 hrs) was also set, when 405mm was recorded at Thirlmere in Cumbria in just 38 hrs.

The weekend’s record rainfall was associated with a persistent, south-westerly flow bringing a ‘river of moisture’ from as far away as the Caribbean and the Gulf of Mexico. Ocean temperatures in the West Atlantic are currently well above normal and may well have contributed to the very high levels of moisture in the air masses which unleashed rainfall on the Cumbrian fells.

Professor Dame Julia Slingo, Met Office Chief Scientist, says “It’s too early to say definitively whether climate change has made a contribution to the exceptional rainfall. We anticipated a wet, stormy start to winter in our three-month outlooks, associated with the strong El Niño and other factors.

“However, just as with the stormy winter of two years ago, all the evidence from fundamental physics, and our understanding of our weather systems, suggests there may be a link between climate change and record-breaking winter rainfall. Last month, we published a paper showing that for the same weather pattern, an extended period of extreme UK winter rainfall is now seven times more likely than in a world without human emissions of greenhouse gases.”








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