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.”





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.





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.





Typhoon Melor bringing stormy weather to the Philippines

14 12 2015

After an extremely active northern hemisphere tropical cyclone season in 2015, the last couple of weeks have been very quiet. This is not unusual as the season often tails off in November and December. However, there has been a sting in the tail in the form of Typhoon Melor. Late last week a disturbance in the western North Pacific started to develop and during the weekend quickly intensified into Typhoon Melor. On Monday morning at landfall, winds averaged over 1-minute peaked near 130 mph which makes Melor equivalent to a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Remarkably that makes Typhoon Melor the 27th tropical cyclone in the northern hemisphere to reach category 4 or 5 this year – a full nine more than the previous record set in 2004.

Melor has already tracked along the north coast of the Philippine island of Samar and has now made landfall over the south-east of the island of Luzon. Population centres such as Sorsogon City and Legazpi City are likely to experience very strong winds and heavy rainfall. Some areas of the central Philippines could see as much as 500-1000 mm of rain fall in the next couple of days which could bring floods and mudslides. Melor is expected to continue westwards towards Mindoro Island before moving into the South China Sea as a weakening storm.

Typhoon Melor at 0710 UTC on 14 December 2015 Image from the Himawari satellite

Typhoon Melor at 0710 UTC on 14 December 2015
Image from the Himawari satellite

Although the main season for typhoons in the Philippines is from June to November, the country has been hit by several storms in December in recent years. In 2012 Typhoon Bopha struck the island of Mindanao with winds near 165 mph causing much damage and numerous fatalities. A year earlier Tropical Storm Washi struck a similar location. Although winds were not exceptional, huge amounts of rain caused flooding and mudslides, again resulting in many casualties.

Official warnings for the latest tropical cyclones in the western North Pacific are produced by the Japan Meteorological Agency. 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.





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.”





Wind and rain records for Storm Desmond

6 12 2015

Storm Desmond, the fourth named storm of the season, bought widespread heavy rain and storm force winds to areas of northern England and Scotland.

The rainfall experienced in many parts of the north west of the UK is thought to have been exceptional and early provisional rainfall statistics indicate many places have seen totals widely over 180 to 200 mm in the Lake District. It is thought very locally event totals may be in excess of 300 mm locally.  The Met Office issued a Red ‘take action’ severe weather warning for rainfall yesterday, the first red warning since February 2014.

48 Hour UK Rainfall Total 0900 4th December – 0900 6th December
Site Name Area Rainfall Total mm
Shap Cumbria 262.6
Keswick Cumbria 178.4
Blencathra Cumbria 174.8
Capel Curig Gwynedd 170.6
Tyndrum Perthshire 141
Eskdalemuir Dumfriesshire 139.2
Bainbridge North Yorkshire 136
Cluanie Inn Ross & Cromarty 132.8

The rainfall caused some rivers to flood and homes had to be evacuated in areas of Cumbria and in Northumberland. The Environment Agency still has a number of flood warnings in place.

An Amber ‘be prepared’ warning for wind was in place for parts of  SE Scotland and NE England as wind speeds were expected that could potentially cause disruption, structural damage and disrupt transport.  Gusts of over 80 mph were experienced in more exposed locations, with the strongest recorded gust of 99 mph at Great Dun Fell, a high level site in Cumbria at 847m.

Max Gust Speeds 5 December 1800 – 6 December 0900
Site Name Area Max Gust mph
Capel Curig Gwynedd 81
Needles Old Battery Isle of Wight 78
High Bradfield South Yorkshire 77
Redesdale Camp Northumberland 73
Loftus Cleveland 70
Aberdaron Gwynedd 69
Charterhall Berwickshire 68
Valley Gwynedd 67

 

There are no weather warnings in place for the rest of today (Sunday), however the Environment Agency and the Scottish Environment Protection Agency (SEPA) still have a number of flood warnings in place as water courses are still reacting to yesterday’s rainfall. A warning is in place for Monday and will be updated as required.

You can keep up to date with the latest forecast using our five day forecast pages, the latest weather warnings on our National Severe Weather Warnings pages and find out what to do in severe weather.





This weekend’s UK rainfall

15 11 2015

Following the heavy rainfall over the weekend, here are the latest rainfall totals:

Site Name Area 48hr Rainfall total 9am Sat to 9am Mon (mm)
Capel Curig Gwynedd 106.0
Lake Vyrnwy Powys 82.0
Keswick Cumbria 81.6
Blencathra Cumbria 72.6
Tyndrum Perthshire 72.4
Shap Cumbria 69.8
Pately Bridge North Yorkshire 69.2
Bala Gwynedd 66.0  

With more unsettled weather on the way this week bringing further rain and strong winds, keep up to date with the latest forecast for your area and see the latest National Severe Weather Warnings.


 

Heavy rain has fallen widely throughout the night across much of north-west England, with the heaviest being over some of the higher ground in Cumbria.  The Environment Agency had recorded rainfall totals of 178mm in 12 hours by 5 am this morning in Cumbria.

National Severe Weather Warnings, still in place for parts of northern England, southern Scotland and Northern Ireland, are valid until this evening when the rain will start to clear out to the southeast.

Rainfall radar image 10pm 14 November 2015

Rainfall radar image 10pm 14 November 2015

The Environment Agency, Natural Resource Wales (NRW) and the Scottish Environment Protection Agency (SEPA) are continually monitoring the flood risk as this rainfall makes its way through the river network.

The amber warning issued for parts of North Wales has now been lifted. However a yellow severe weather warning is still in place until 10 pm this evening. Met Office rain gauges recorded 76mm in the 24 hour period up to midday today (Sunday) at Capel Curig in Snowdonia.

Warnings are constantly under review and adjusted should the weather system change or develop and potential impacts vary.

Regions/Country  Rainfall gauge  24hr rainfall total 9am Sat to 9am Sun
Cumbria Keswick 60mm
Cumbria Spadeadam 45.8mm
North Yorkshire Grimwith 65.4mm
West Yorkshire Thornton Moor 70mm
Lancashire Colne 60.2mm
Wales Capel Curig 67.2mm
Northern  Ireland Castlederg 42,6mm
Scotland Threave 48mm

Many parts of northern and central UK will continue to see rain today, some of it heavy, especially within the warning areas.  You are advised to keep up to date with the latest forecast information for your area so you can plan and prepare for the expected weather.

The Environment Agency, NRW and SEPA are still concerned that additional rainfall on to already saturated ground could well still lead to flooding and you are advised to keep up to date with the latest flood warnings and advise.

This weekends heavy rainfall heralds the start of an unsettled week as a series of low pressure systems are expected to move across the country.  The first will arrive late Monday before another brings stronger winds and rain on Tuesday and another system brings rain on Wednesday.  National Severe Weather Warnings have been issued for some of these systems given the now saturated ground over parts of the UK and will be updated in the coming days.  Meanwhile the weather is expected to turn colder for many by the end of the week.





Wet weekend for parts of the UK

12 11 2015

Heavy rain is expected across parts of north Wales, northwest England and southwest Scotland on Saturday into Sunday, clearing to the southeast on Monday.  We have issued a yellow weather warning for rain for these areas, while the Environment Agency, Natural Resource Wales (NRW) and the Scottish Environment Protection Agency (SEPA) are assessing the potential flood risk.

A slow moving frontal system is bringing moist tropical air across the UK from the west resulting in some heavy and persistent rain, especially over exposed hills.  Parts of the warning area could see 70-100 mm of rain, with some of the more exposed parts of north Wales and northwest England possibly seeing as much as 150-200 mm through the period.

Pressure Chart 15th November 2015

Pressure Chart 15th November 2015

The Environment Agency is concerned that this amount of additional rainfall falling on to already saturated ground could well lead to flooding, either from standing water, or from rivers bursting their banks. Flood warnings have been issued for parts of northern England.

NRW are planning to put flood risk management procedures in place if required and will issue Flood Alerts and Warnings if rivers reach trigger levels. The warnings are updated on the NRW website every 15 minutes.

The warnings will be kept under review and adjusted should the weather system change or develop and potential impacts vary.





Cyclone Chapala brings flooding rains to Yemen

3 11 2015

Our blog yesterday reported on the imminent landfall of Cyclone Chapala which was located in the Gulf of Aden. As expected the cyclone made landfall over Yemen in the early hours of Tuesday UK time. Winds averaged over one minute were estimated to be near 75 mph at landfall which is equivalent to a category 1 hurricane.

However, it is the rainfall which poses the biggest threat. The coastal strip of Yemen is usually very dry with approximately 50mm (2”) rain per year. Chapala is likely to produce 100-200mm widely and as much as 500mm in some locations. Although Chapala has weakened to a tropical storm it has become very slow-moving near the coast which increases the threat from heavy rainfall.

Cyclone Chapala at 0715 UTC on 03 November 2015 Image courtesy of NASA

Cyclone Chapala at 0715 UTC on 03 November 2015
Image courtesy of NASA

Observing stations are few and far between in this part of the world, but images and videos being posted in online media indicate that flooding is occurring in populated areas under the path of the cyclone such as the city of Al Mukalla.

The last time heavy rains from a tropical cyclone occurred in this region was 2008. This event caused much destruction and loss of life even though it was only classified as a tropical depression. Cyclone Chapala was a much stronger cyclone and thus has a much greater potential for disruption and damage.

Given the disruption caused by Cyclone Chapala, there is heightened interest in an area of disturbed weather developing to the west of India. This has the potential to develop into a tropical storm and latest forecasts suggest it will move west across the Arabian Sea. It is too early to be sure about the likely intensity and precise track of this disturbance, but it is being watched closely for further development.

Image of Arabian Sea at 1130 UTC on 03 November 2015 Image courtesy of US Naval Research Laboratory

Image of Arabian Sea at 1130 UTC on 03 November 2015
Image courtesy of US Naval Research Laboratory

Official warnings for the latest tropical cyclones in the Arabian Sea are produced by the India Meteorological Department. 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.





World weather this week

26 10 2015

Southern USA
After making landfall on Saturday 23 October as a category 5 hurricane, Hurricane Patricia weakened rapidly as it moved over the mountains of Mexico. Hurricane Patricia became the deepest hurricane on record with minimum central pressure of 879hPa, beating the previous record of 882hPa set by Hurricane Wilma in the Atlantic in 2005. The remnants of Patricia formed an area of low pressure over the Gulf of Mexico over the weekend and brought intense rainfall to the southern states of the USA. Severe flood impacts were reported in parts of Texas and Louisiana with up to 500mm of rain reported. New Orleans reported 220mm in the last 24 hours with an unconfirmed total of 457mm in 24 hours at Corsicana, Texas. This torrential rain also led to delays at the USA Grand Prix. The eastern fringes of Texas, along with Louisiana, Mississippi, Alabama and Arkansas are at risk of receiving another 100-200mm of rainfall today (Monday) bringing further flooding impacts. Looking ahead, further heavy rainfall will affect areas of the Pacific coast of Mexico that were impacted by Patricia; Texas and Louisiana from Friday with another 200mm or more of rain. This will exacerbate the current flooding in these regions.

Hurricane Patricia

Map showing rainfall totals across Mexico and the southern states of the USA

Eastern Mediterranean
A spell of very unsettled weather is affecting the eastern Mediterranean bringing heavy rainfall, localised flooding to the Levant coasts along with reports of baseball-sized hail in parts of Egypt. This weather will continue to move eastwards across countries such as Syria, Israel, Lebanon and into Iraq and Iran over the coming days with daily rainfall likely to approach 100mm. This will lead to a risk of flash flooding and may be accompanied by further damaging hail.

Sri Lanka and SE India

Heavy rain associated with the northeasterly monsoon has brought some high rainfall totals across Sri Lanka with 89mm recently recorded in 3 hours. There is a risk of a tropical depression forming in the southern Bay of Bengal this week which would bring further very heavy rainfall across Sri Lanka and SE India. Some places may see up to 200mm a day, with an event total of up to 600mm. This will lead to significant flood and landslide risk across this region, with the large Indian city of Chennai and Sri Lanka capital Colombo at risk.

Eastern Canada/NE USA and eastern Europe

Over next weekend and early next week, a cold plunge of air is likely to dip southwards across the eastern provinces of Canada and far northeastern states of the USA such as Maine, New Hampshire, Vermont and Massachussetts. Daytime temperatures may only just rise above freezing in what will be a fairly early cold snap for the regions.

Cold air will also sink southwards from the arctic to bring an early taste of winter to eastern Europe affecting Ukraine, Belarus, Poland and also western Russia.








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