A brief spell of heat and thunderstorms

11 06 2015

Southern parts of the UK can expect some very warm and humid conditions on Friday, along with an increasing risk of some heavy, thundery showers.

Partial thickness values from the Met Office Global Model for 1200Z Friday 12 June

Partial thickness values from the Met Office Global Model for 1200Z Friday 12 June

Isolated thunderstorms are possible from Thursday, but they will become more likely and potentially more severe by Friday afternoon, with some locally torrential downpours possible, especially for parts of southeast England. A yellow warning has been issued for heavy rain. There is the potential for large amounts of rain is a short space of time, and this could lead to surface water flooding, but as is the case with showers, some places will stay dry. We are also likely to see frequent lightning, and hail is possible in places – as we saw last Friday.

Away from the south, there will be sunshine for many, though it will be cloudier with a little light rain in the far north.

Into the weekend, temperatures will take a tumble across much of the country. Saturday will see a band of rain across central areas, with occasional brighter spells either side. The rain will become increasingly light and patchy by Sunday with drier conditions developing for many. It will feel noticeably cooler though, with the return of some chilly nights.

Partial thickness values from the Met Office Global Model for 1200Z Sunday 14 June

Partial thickness values from the Met Office Global Model for 1200Z Sunday 14 June

With many people out and about at this time of year including at the Isle of Wight and Download festivals, we should be prepared for all types of weather over the next few days, from humid to cool and from rain to shine.





Summer returns but no heatwave

2 06 2015

There have been some stories in the press that a heatwave is on the way later this week.  Although we are expecting temperatures to rise over the coming days with some pleasant early summer weather, any very warm weather will be fairly short-lived.

After an unseasonably cold, wet and windy start to June and the meteorological summer, high pressure is expected to build across southern parts of the UK from Wednesday, resulting in a much quieter and more pleasant spell of weather.

By Friday, a plume of hot air from the continent could bring temperatures in the mid 20s°C  across south eastern parts of the country, but this in turn is likely to trigger some thundery showers. So although temperatures are likely to peak on Friday, this may not necessarily be accompanied by blue skies and sunshine, as a good deal of cloud is possible along with rather humid and hazy conditions.

Deputy Chief Meteorologist Martin Young said “although things will be a good deal warmer than of late, there still remains considerable uncertainty about how hot it will be and exactly where will see the highest temperatures on Friday, and the public should keep in touch with the latest forecasts”.

This coming weekend is likely to see temperatures a little lower than Friday’s in the south east, but plenty of pleasantly warm sunshine is expected across much of the UK with temperatures widely in the high teens, and reaching the low 20s°C  in parts of the south.





Possible record heat in Spain, while heavy rain and snow affect the Alps

13 05 2015

Parts of Spain, Portugal and southern France are experiencing unusually high temperatures at the moment. On Tuesday, Seville recorded 38C, and today will be another very hot day for the time of year, with temperatures widely expected to reach the low to mid 30s Celsius.

Met Office Global Model mean sea level pressure and temperature

Met Office Global Model mean sea level pressure and temperature

The hottest conditions will be across the Andalucía region of southern Spain. If temperatures reach or exceed 40C in Seville today this will be a new May record. Cooler conditions will gradually spread from the north tomorrow, although another very hot day is likely in southern Spain. Temperatures are then expected to return closer to average in all regions by Friday.

Meanwhile, southern Germany, Switzerland, Austria, and northern Italy are at risk of heavy rainfall over the coming days, with heavy snow possible on Friday across the Alps. Up to 150mm of rain could fall within 48 hours, possibly leading to flash flooding and landslides in this mountainous region of Europe, as well as increasing the avalanche risk due to fresh snowfall.

Whilst neither of these two weather events in Europe will affect the UK, we are expecting some heavy rain of our own on Thursday. The band of rain will move across southwest England during the early hours and edge slowly northeastwards through the day, but become almost stationary across parts of Wales, central-southern and southeast England. However, northern England, Northern Ireland and Scotland will remain largely dry and fine.





Ten Tors

8 05 2015

This weekend sees the 2015 Ten Tors challenge and once again, the Met Office will be providing tailored forecasts for the organisers to help with event planning and coordination. This year, for the first time, an Operational Meteorologist will also be at Okehampton Camp for the weekend, providing the latest information on weather conditions across Dartmoor throughout the event to help the organisers make the necessary decisions to keep the teams safe.

Forecast

Chief forecaster Dan Suri said “The event may start on rather a wet note, with some heavy showers likely on Saturday morning”. These showers will clear later in the morning leaving a drier and brighter afternoon. It will be breezy too, making it feel quite chilly in the wind. Saturday night will be largely dry, but it is likely to become murky through the early hours of Sunday, with occasional drizzle and hill fog. The cloud base will probably lift a little during Sunday morning, but higher parts of the Moor are likely to stay murky, and whilst the odd brighter spell may develop with shelter from the wind, it will remain largely cloudy. Still quite breezy on Sunday too.

The challenge

The weather plays a major part in the successful completion of the event for everyone taking part. Around 400 teams of six take part in the challenge to complete the course. There are three different course lengths, depending on the age and ability of the team:

  • 35 miles
  • 45 miles
  • 55 miles.

The idea of the challenge is for the teenagers to become self-sufficient for the weekend – carrying everything they’ll need for the trek and making their own decisions.

At this time of year, conditions can be varied, from torrential rain to hot sunshine.

Ten_Tors_infographic_2015

For more information about the event, including the latest weather and a video explaining the variety of conditions you might expect on Dartmoor, take a look at our events pages.

Our National Park forecast service includes forecasts for a wide range of locations on Dartmoor, many of which are included within the Ten Tors event. You can also find forecast information on our weather pages.





Active tropical storm season in the Northwest Pacific as another typhoon heads for the Philippines

7 05 2015

Typhoon Noul is currently to the east of the Philippines in the Northwest Pacific, and is heading steadily west-northwest. Noul is expected to continue moving towards the Philippines whilst intensifying further to a very strong typhoon. The storm is expected to make landfall in the Philippines this weekend.

Noul pacific sat pic

There is still some uncertainty in the exact track, but currently Noul looks likely to make landfall on the east coast of Luzon, bringing very strong winds with gusts of 130kt (150mph), coastal and inland flooding with total rainfall accumulations of up to 400mm possible, and potential landslides across large parts of northern Luzon. There is also a risk of significant impacts in Manila if Noul takes a slightly more southerly track.

Track from Japan Meteorological Agency

Track from Japan Meteorological Agency

Although the typhoon is expected to weaken next week, Noul could also bring some heavy rain to parts of Japan.

This is the sixth tropical storm of the north-west Pacific season and the fourth to become a typhoon, which is an unusual level of activity so early in the season. And yet another tropical storm looks set to develop behind Noul, possibly following a similar path.

The Met Office works closely with counterparts at the Philippines weather service PAGASA, providing the latest information on computer model predictions of the likely track and intensity of Typhoon Noul as it nears the country.

Official warnings of west Pacific tropical storms 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.

Met Office StormTracker provides a mapped picture of tropical cyclones around the globe with access to track history and six-day forecast tracks for current tropical cyclones from the Met Office global forecast model and latest observed cloud cover and sea surface temperature. We also provide updates on current tropical storms via @metofficestorms on Twitter.





Intense storm threatens Sydney

22 04 2015

Parts of New South Wales in southeast Australia have had severe flooding and wind damage over the past few days due to an intense low pressure system. Parts of the region have already seen more than 300mm (around a foot) of rainfall. Areas around Sydney have been affected, with flooding claiming three lives and causing evacuations of properties, as well as disrupting power and transport. Officials warned that hundreds of homes in the city are under threat from rising river levels, and it has been reported that the State Emergency Service (SES) have received nearly 10,000 calls for help and carried out more than 100 rescues.

Analysis chart from Austrlian Bureau of Meteorology

Analysis chart from Austrlian Bureau of Meteorology

The storm is now weakening and moving away southeastwards into the Tasman Sea, so conditions are expected to improve over the next 24 hours, however remnants of the system are likely to bring a further 50 to 75mm of rainfall to some coastal parts today, before conditions gradually become quieter.

Rapid Response image from NASA

Rapid Response image from NASA

For more information on current warnings and forecasts across New South Wales, visit the Australian Bureau of Meteorology website.





Two cyclones to hit Australia

19 02 2015

Whilst here in the UK, we are coming towards the end of our winter season, Australia is coming towards the end of summer, but is in the middle of its cyclone season, and unusually there are currently two tropical cyclones affecting the country.

Severe Tropical Cyclone Lam is currently to the north of Australia’s Northern Territory, in the Arafura Sea. The storm is expected to make landfall on Thursday as a category 4 storm, between Milingimbi and Gapuwiyak. Huge rainfall figures are forecast, with 300 to 600mm daily, potentially adding up to more than 800mm in places throughout the storm event, with flooding likely inland, as well as coastal flooding and damaging winds. Residents close to the coast have been advised to be ready to move to shelter with emergency kit. However, as the area is not densely populated, significant impacts are not expected. The nearest large population centre is Darwin, and although it is likely that there will be some wet and windy weather here, it is not expected to be anything that Darwinians aren’t used to.

Credit: Courtesy of the Naval Research Laboratory

Credit: Courtesy of the Naval Research Laboratory

Storm track and warning areas for Tropical Cyclone Lam

Storm track and warning areas for Tropical Cyclone Lam

Meanwhile, Severe Tropical Cyclone Marcia is heading towards the Queensland coast, and is expected to make landfall between Mackay and Gladstone on Thursday night as an extremely powerful category 5 storm. The Australian Bureau of Meteorology are forecasting Marcia to track inland for a while and quickly weaken, before turning parallel with the coast, which keeps the main risk area to the north of Brisbane. However, there is some uncertainty with the exact track of the storm, and if it were to remain closer to the coast, Brisbane could be in line for a significant amount of rainfall, potentially as much as 400mm. Destructive winds are likely around the coast and abnormally high tides will be experienced with water levels expected to rise above the highest tide of the year. Dangerous storm tides are forecast as the cyclone crosses the coast, as well as treacherous surf on exposed beaches.

Credit: Courtesy of the Naval Research Laboratory

Credit: Courtesy of the Naval Research Laboratory

Storm track and warning areas for Tropical Cyclone Marcia

Storm track and warning areas for Tropical Cyclone Marcia

Met Office StormTracker provides a mapped picture of tropical cyclones around the globe with access to track history and six-day forecast tracks for current tropical cyclones from the Met Office global forecast model and latest observed cloud cover and sea surface temperature. We also provide updates on current tropical storms via @metofficestorms on Twitter.





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.

rainfall

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.





Cold Weather for UK

26 01 2015

Cold weather is again on the way for the UK.  Later this week colder conditions will spread south, bringing a mixture of sunny spells and snow showers from Wednesday onwards.  Temperatures for many will be below normal for the time of year and the wind chill, due to strong winds, will make it feel very cold.

Snow showers are expected to affect parts of the northern half of the UK on Wednesday and Thursday and the Met Office has issued a yellow severe weather warning  for the potential impacts and this will be updated as required this week.  Don’t be surprised to see some snow showers across southern areas too, but these are not currently expected to be heavy enough for the snow to settle.  The northerly winds and cold weather are likely to continue into the weekend.

Is it due to the polar vortex?

There have been reports the cold weather is due to a “displaced polar vortex”.  The large-scale low pressure area in the stratosphere, known as the Polar Vortex, is displaced towards Russia and looks likely to stay that way over the next few days.  However this is not directly responsible for changes in the weather during the coming days. The cold northerly winds we are expecting at the end of the week are not unusual for winter.

What is the jet stream doing?

The jet stream is forecast to move south of the UK from Wednesday onwards. This means we will be on the ‘cold side’ of the jet and cold air from the poles/Arctic will work its way southwards to affect the UK.

Jet Stream forecast map for Saturday showing the track to the south of the UK.

Jet Stream forecast map for Saturday showing the track to the south of the UK.

Is the snowstorm in the USA coming our way?

The snowstorm affecting the east coast of the USA is not coming towards the UK.  It is expected to move away from the States, crossing the Atlantic to the south of the UK to bring heavy rain to Spain and Portugal at the end of the week.

 

 

 





Why are we now seeing colder weather across the UK?

16 01 2015

Over recent weeks, we have spoken about the very strong jet stream across the Atlantic, driving areas of intense low pressure towards the UK. This has bought spells of very wet, windy but relatively mild conditions to the country.

As many of you would have noticed, although the wind and heavy rain has eased, there is now a colder feel to the weather, both by day and night. But what has caused this change in the weather?

Once again the change is down to the jet stream. It has weakened and its track has moved further south, keeping the deep low pressure systems away from our shores. However, now the UK is to the north of the jet stream we are on its cold side, and this has allowed colder weather to feed in across the country.

Current jet stream

Current jet stream across the Atlantic

So what does this mean for us?

As we look ahead into the weekend and next week, the cold weather looks likely to continue. Daytime temperatures will be near or below average and there will be some frosty nights, as temperatures fall below freezing in many areas. We’ll see some sunny spells around and there will also be showers or longer spells of precipitation in places, giving a mixture of rain, hail, sleet or snow, which may settle in some areas.

Because of the threat of wintry weather over the coming days, we encourage everyone to keep up to date with the latest forecasts and national severe weather warnings and to stay weather aware this winter by following the Met Office on Twitter, Facebook, Google+ and YouTube for the latest weather information. You can find information about how to prepare for every aspect of the winter season at Get Ready for Winter.

As we head towards the latter part of the month, we can see some indications that milder weather may return, but there is considerable uncertainty about this so far in advance.








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