Warm start to November

16 11 2015

Early provisional figures* (1-15 November) show the first half of November has been very mild with maximum daily temperatures 3.8C above average for the UK

Central England Temperature data set shows the start to the month has been the second warmest since this record began in 1772.

Local temperature records have been broken at various stations with only November 1938 seeing a warmer start to the month.

There has been an absence of frosts in almost all areas, largely because a humid south-westerly airflow means the weather has been cloudy and there have been very few clear nights.


MeanTemp 1-15 November 2015

MeanTemp 1-15 November 2015

The increased cloud means most areas have seen very little in the way of sun, with levels well below normal across southern and central England and also south-west Scotland. At this time in the month we would expect to see 50% of the monthly average however very few places have had as much as this and the UK as a whole has seen just 32% and Wales has seen less than half the sunshine we would expect mid month.   In the case of southern England it has also been remarkably dull, with some stations having only had 10 hours or less of bright sunshine in 15 days.

For many the start of the month has been wet, with the UK as a whole having had 75% of the whole months average rainfall (we would expect to see 50% at this time of the month). Parts of southern & central Scotland, the Lake District, Pennines and Snowdonia are among the areas already well above their whole-month average. However it was not a wet picture across the whole country, north-east Scotland and most of southern & eastern England have had slightly less rain than would be expected by this point in the month.

EARLY mean temperature sunshine duration precipitation
1-15 Nov 2015 Act Anom  Act Anom  Act Anom 
  degC degC hours % mm %
UK 10.0 3.8 18.1 32 90.5 75
England 11.2 4.3 17.5 27 59.8 68
Wales 10.7 3.9 20.3 36 128.5 79
Scotland 8.0 3.0 18.4 40 132.5 80
N Ireland 9.6 3.1 18.3 34 83.1 74


For the rest of November indications are that after an unsettled week the weather will turn colder with temperatures dropping nearer to the expected average for Novemeber if not a little below.  However milder conditions look likely to return for a time at the end of the month with rain and strong winds for much of the UK.

Please note that these provisional figures, especially for rainfall & 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.

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.

The impacts of Typhoon Koppu

19 10 2015

Typhoon Koppu made landfall in the early hours of Sunday (local time) close to Casiguran in northern Philippines as an intense Typhoon. At landfall it was equivalent to a category 4 Hurricane with sustained winds averaged over a minute estimated to be close to 155 mph with gusts near 185 mph. There were reports of significant storm surge/large waves.

Through Sunday Koppu tracked slowly west across Luzon and was near San Fernando this morning (Monday) where it was downgraded to a Tropical Storm. It is expected to continue slowly across the north of Luzon through Monday and much of Tuesday.

Satellite image courtesy of the Joint Typhoon Warning Center.

Satellite image courtesy of the Joint Typhoon Warning Center.

Rainfall and flooding are now the main threat with torrential rain forecast in areas over the next 48 hours. 238mm was recorded in the city of Baguio in just 6 hours earlier today.  Total rainfall from Saturday to Tuesday could be as high as 1500mm in places. Several dams are at risk of overflowing and there is a significant landslide risk in the coming days.

There is considerable uncertainty in the track of Koppu as it clears the Philippines later this week. Some models take this system north, perhaps strengthening into a typhoon again and producing a risk of flood impacts in parts of Taiwan. However, it is possible Koppu could move north-east avoiding any impact on Taiwan, but posing a threat to the Ryukyu Islands of Japan.

Hurricane Joaquin lashes the Bahamas but will it hit the USA?

1 10 2015

In recent months attention has focused on the very active tropical cyclone season in the Pacific Ocean brought about primarily by the strong El Niño which has developed this year. Meanwhile, the Atlantic has been very quiet with most tropical storms remaining fairly weak and only two reaching hurricane strength until now.

However, Joaquin has become the third hurricane of the Atlantic season and the second to achieve ‘major’ status – category 3 or above on the Saffir-Simpson Hurricane Wind Scale. Joaquin is currently lashing the Bahamas with winds in excess of 100 mph near the centre of the hurricane. A storm surge of over two metres is possible and rainfall totals could be as high as 500 mm. Once the hurricane starts moving away from the islands the big question is whether it will make landfall over the US east coast.

Hurricane Joaquin at 1237 UTC on 01 October 2015 Image courtesy of the US Naval Research Laboratory [local copy at http://www-nwp/~frjh/tropicalcyclone/images/nhem15/joaquin_20151001_1237z.png]

Hurricane Joaquin at 1237 UTC on 01 October 2015
Image courtesy of the US Naval Research Laboratory

The forecasting conundrum

Joaquin is currently slow moving near the Bahamas and all computer models agree that a gradual turn north will happen in about two days time. However, beyond this point there is great uncertainty as to what will happen. Joaquin is being pulled in two directions. A developing trough of low pressure over the USA would act to pull Joaquin westwards towards the US coast. However, an area of low pressure to the east – including the remnants of Tropical Storm Ida – would act to pull Joaquin east away from the USA. The situation is finely balanced and any of several outcomes could happen.

One scenario is that Joaquin could make a turn north-westwards and make landfall near the Outer Banks of North Carolina at the weekend. Computer models are now mostly moving away from this as a likely outcome. Alternatively, Joaquin could take a mostly northwards track and reach New York and New England by early next week then continue up the eastern seaboard of Canada. Finally, a third scenario allows for the possibility that Joaquin could turn north-eastwards and avoid a US landfall altogether. We recommend that a close watch is kept on guidance issued by the National Hurricane Center in coming days for updates on which scenario is the most likely to occur.

Irrespective of whether or where Hurricane Joaquin makes landfall on the US east coast, large amounts of rain are expected in this area in the coming few days due to a slow-moving frontal zone. The impact of this will be exacerbated if Hurricane Joaquin does take a turn towards the USA in the next few days with further heavy rain accompanied by strong winds and a storm surge.

 Latest forecast track of Hurricane Joaquin from the National Hurricane Center

Latest forecast track of Hurricane Joaquin from the National Hurricane Center

Recent history of US landfalling hurricanes

Hurricane strikes on the USA have been fairly infrequent in recent years – particularly those at the stronger end of the scale. In 2014 Arthur crossed the Outer Banks of North Carolina as a category 2 hurricane. Going back to 2012, Isaac came ashore over Louisiana as a minimal category 1 hurricane. In 2011 Irene made landfall on the east coast of the USA also as a category 1 hurricane. The USA avoided hurricane strikes altogether in 2010 and 2009, but in 2008 three made landfall, the most significant of which was Hurricane Ike which caused a huge storm surge as it came ashore over Texas as a category 2 hurricane. However, you have to go back to 2005 to find the last ‘major’ hurricane strike on the USA (category 3 or above), when Hurricane Wilma hit Florida.

Hurricane Sandy (sometimes referred to as ‘Superstorm Sandy’) also caused much devastation to parts of the USA east coast in 2012. It is ranked as the second most costly hurricane in US history, although technically ceased to be a hurricane just prior to the time it made landfall.

Official warnings for the latest tropical cyclones in the 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.

Will Joaquin affect the UK?

With the confidence around the exact track of Joaquin being so low, it is currently too early to tell if this system will affect the weather in the UK. There is, however, already high confidence that we will return to more autumnal and unsettled conditions across the UK early next week. Make sure you keep up-to-date with the Met Office five-day forecast.

So what happened to our summer?

28 08 2015

Our Chief Scientist Professor Dame Julia Slingo OBE FRS reflects on this summer’s weather and what has influenced it:

No-one can deny that we have had a pretty disappointing summer with a lot of unsettled weather and only a few warm spells, especially through July and August. Our weather has been dominated by low pressure over and to the west of the country that has brought us periods of heavy rain from the south – what we call the Spanish Plume. So what has been happening?

If we look beyond our shores there have been some big changes in the global climate this year. El Niño is in full flight, disturbing weather patterns around the world. The low pressure that has dominated our weather is part of a pattern of waves in the jet stream around the world that has brought crippling heat waves to places like Poland and Japan. And, looking back over past El Niños, you could have expected that a more unsettled summer might be on the cards for the UK. Closer to home the North Atlantic is more than 2 degrees colder than normal. It seems quite likely that the unusually cold North Atlantic has strengthened and pushed our jet stream south, also contributing to the low pressure systems that have dominated our weather.

So could all this have been anticipated? Seasonal forecasts for this summer suggested that temperatures and rainfall would be near normal. However, as the season progressed all the leading models around the world failed to capture the signal for unsettled weather over the UK. We all know that forecasting months and seasons ahead is still in its infancy and much more research needs to be done. On the other hand our day-to-day forecasts have been really successful in allowing us to warn of bad weather, highlighting yet again the benefits of our research that has delivered year-on-year and decade-by-decade improvements in forecasting skill. Our 5-day forecast is now as accurate as our 1-day forecast was when I started my career. This enables us to make so many decisions that keep us safe, protect our property, keep our infrastructure running and even when to go out and enjoy the sunshine!

All of this cannot happen without improvements to research and technology, and this week the first phase of our new supercomputer went live, five weeks ahead of schedule. This will enable us to provide even more accurate and relevant weather and climate forecasts to all of us, our government, emergency responders, and our many other customers at home and abroad.

The news that the BBC has decided that the Met Office won’t be their main weather provider when the current contract ends has raised the question of where will the new provider get their information from. It’s important to understand that no weather forecasting organization, whether it is a National Met Service like the Met Office or an independent company, can provide a service without a forecast, and that it is the leading meteorological agencies, like the Met Office, that build and deliver those forecasts. So whoever the BBC chooses to deliver their weather services in future, you can be sure that Met Office observations and forecasts will continue to be at the heart of them. We are committed to driving forward the skill and usefulness of our forecasts and ensuring that all of us benefit from the advances the Met Office makes in the coming years with our new supercomputer.

Highest temperatures and rainfall over the weekend

23 08 2015

Over the past 24 hours the weather has delivered a mixture of hot sunshine, thunderstorms, hail and heavy rain as we highlighted earlier in the week.

As expected, sunny skies and warm air being pushed northwards from the continent allowed temperatures to climb across central and eastern parts of the UK, reaching maximums in the high 20s and low 30s on Saturday with a humid feel:

Table showing Maximum temperatures for Saturday 22 August 2015

Location Maximum Temperature in C
Gravesend 30.9
Kew Gardens 30.9
Heathrow 30.7
St James’s Park 30.7
Northolt 30.6

These high temperatures set off two areas of thunderstorms, one over central southern England and another over the Midlands, moving into northern England. These storms caused localised surface water flooding and flooding of some properties in North Yorkshire as up to 30mm of rain fell in an hour. There were also impacts to the York-Leeds rail line.

Across the northwest of the UK it was fresher and mainly dry with some sunshine, while the areas in between were rather cloudy with some rain.

Overnight, the heavy, thundery downpours continued to move northwards, while heavy rain also spread into western parts of the UK. By this morning at 10am the rainfall totals for the 24 hours were as follows:

Table showing rainfall totals for the 24 hours up until 10am on Sunday 23 August 2015

Location Rainfall in mm
Bramham 62.6
Ryhill 54.6
Tredegar 40.6
Linton-on-Ouse 39.8
Scolton Country Park 36.8

During today, the heavy rain has continued to spread north and eastwards with a mixture of sunny spells and heavy showers following across the south. Ahead of this, temperatures across eastern England have again peaked in the mid to high 20s.

Table showing rainfall totals bwtween 10am and 4pm on Sunday 23 August 2015

Location Rainfall in mm
Hereford 20.8
Llanbrynmair 20.4
Sarn 17.8
Lake Vyrnwy 17.2
Porthmadog 17.2

The changeable weather will continue as we head into next week. Met Office National Severe Weather Warnings have been issued and everyone is encouraged to keep up to date with forecasts and warnings over the next few days and to make plans accordingly.

A wet getaway

24 07 2015

As many of us plan to head off on holiday, heavy rain and strengthening winds cross southern England today (Friday), persisting overnight in the east, before clearing on Saturday morning.

A Yellow warning has been issued for southeast England and East Anglia, valid from Friday afternoon to 11am Saturday because of the potential impacts the heavy rain and wind could have.


Weather warning 24.07.15

As an area of low pressure is crossing northeastwards across the UK today (Friday), close to southern England, it deepens into quite an intense feature for this time of year and is expected to bring disruptive rain and wind, particularly within the warning area.

More than 30 mm of rain is expected quite widely, but there is a chance some isolated locations could well see more than 70 mm of rain. Wind gusts are also expected to be strong across the warning area, with northerly winds gusting to 45 mph inland and around 55 mph along coasts. This combination of factors could bring the risk of disruption to outdoor activities and heavy holiday traffic.
Highways England has launched a website especially for drivers heading to the South West of England to help plan their journey.

One year on – A look back to last winter

17 02 2015

This weekend marked the one-year anniversary of the Valentine’s Day storm, which also marked the end of a particularly stormy three-month period. A new review article – ‘From months to minutes – exploring the value of high-resolution rainfall observation and prediction during the UK winter storms of 2013/2014’ – written by 16 Met Office co-authors reviews the accuracy of our forecasting and warning of severe weather during winter 2013-14, and assesses its performance.

The paper concludes that the “prolonged period of high impact weather experienced in the United Kingdom during the winter of 2013/14 was very well forecast by the operational tools available across space and time scales.”

Here Huw Lewis, the paper’s lead author, and Derrick Ryall, Head of the Public Weather Service, look at the extreme weather last year and the role of the Met Office in communicating severe weather through the National Severe Weather Warning Service.

Analysis chart 1200 GMT 26 January 2014

Analysis chart 1200 GMT 26 January 2014

Winter 2013/2014 in the United Kingdom was remarkable. The country was battered by at least 12 major winter storms over a three month period and was officially assessed as the stormiest period that the United Kingdom has experienced for at least 20 years.

The series of storms resulted in the wettest winter in almost 250 years (according to the England and Wales precipitation series from 1766), significantly wetter than the previous wettest winter in 1914/1915.

Snapshot of UK rain radar surface rainfall rate for 2200 GMT on 23 December 2013

Snapshot of UK rain radar surface rainfall rate for 2200 GMT on 23 December 2013

The extreme weather caused widespread flooding throughout Southern England and coastal damage – most notably in the South West and Norfolk coasts. The impact of the severe winter storms on individuals, businesses and the government were substantial, including several fatalities, widespread power cuts and damaged infrastructure.

Recent advances in forecasting, technology and the scientific developments in meteorology have been considerable. These developments and improvements in accuracy mean that a four-day weather forecast is as accurate as a one-day forecast was just thirty years ago. During the course of last winter, the Met Office was able to use these forecasts to warn of any severe weather well in advance. In the case of the St Jude’s Day storm at the end of October 2013 warnings went out to the Government and the public five days before the storm even existed.


As the accuracy of weather forecasts has evolved, so has the communication of the potential impacts of severe weather. The National Severe Weather Warning Service enables more ‘weather decisions’ which in turn help to minimise the consequences of severe weather. The Met Office was at the heart of the government response to the storms, providing advice on weather impacts through the National Severe Weather Warning Service and Civil Contingency Advisors. The Met Office also worked very closely with both the national and regional media, who in turn played a key role in ensuring that the public were fully informed about the potential impacts of any up-coming weather.

In addition to the Public Weather Service, commercial partners and customers were also provided with detailed updates throughout the period in order for them to plan effectively for logistical issues. Together, these advanced warnings helped authorities, businesses and individuals to be better prepared to take mitigating actions.

Driving further improvements in accuracy and therefore reducing the lead time and increasing the detail of severe weather warnings is one of the Met Office’s key priorities . The ultimate aim is to improve the potential for users to plan preventative measures for severe weather events much further ahead. Underpinning all of these developments is a continuing programme of scientific research and access to enhanced supercomputing over the next few years.


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