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.





First half of April has been dry and warm

17 04 2015

Early statistics up to the 15th of April show that month so far has been generally settled and warm, with limited rainfall in most areas.

The mean temperature for the UK was 8.2C, which is 0.8C above the long-term (1981-2010) average for the whole month.

Daytime temperatures have risen to well above average in many areas, especially in the south, with the year’s highest temperature so far of 25.1C recorded at Frittenden in Kent on the afternoon of the 15th. This is the highest April temperature anywhere in the UK since 2011.

The UK as a whole has seen average maximum temperatures 1.4C above normal, though much closer to average in coastal parts of northwest England and western Scotland.

Map shows the UK mean temperature for 1-15 April compared to the whole month average.

Map shows the UK mean temperature for 1-15 April compared to the whole month average.

Rainfall has been well below normal so far in most areas. After 15 days of the month you’d expect about 50% of the full-month average to have fallen in a ‘normal’ April, but the UK has seen just 35% (25.2mm). However, there was some persistent and heavy rain across parts of northwest Scotland on 13th and 14th, and parts of western Scotland have had most of the whole-month average already.

It has also been rather a sunny month so far for most parts of the UK, with 63% of the full-month average already – again you would expect around 50% by mid-month.

The forecast for this weekend is for a good deal of dry and bright weather. However, it’s still far too early to judge how this April will finish overall, with half of the month still to add in to the statistics.

Mean Temperature Sunshine hours Rainfall  
1-15 Apr
Actual Diff to Avg Actual % of Avg Actual % of Avg
  degC degC hours % mm %
UK 12.9 1.4 92.8 63 25.2 35
England 14.0 1.6 98.4 63 14.1 24
Wales 13.5 1.9 92.0 60 20.1 22
Scotland 10.8 1.1 85.8 64 43.7 48
N Ireland 12.8 1.2 81.5 56 32.6 44

Data from the Met Office’s UK digitised records dating back to 1910. You can explore our climate data on our website. Clearly these are early month figures and the statistics at the end of the month will change somewhat.





More warm weather this week – but what’s in store for the summer?

13 04 2015

This week is set to see some unseasonably warm weather for parts of the UK – with temperatures expected to climb to the low to mid-20s Celsius in the south on Tuesday and Wednesday.

Warm air flowing up from the south west will combine with high pressure, bringing settled conditions and sunny spells for many.

Warmest days of the year so far

This week’s above average temperatures follow on from a similar spell last week, which saw temperatures top out at 21.9C at St James’s Park in London on Friday.

This was the ‘warmest day of the year so far’, but It looks like Tuesday and Wednesday will top that – which is to be expected as we head through spring and edge closer to the start of summer.

Unfortunately, the weather we get in April doesn’t necessarily tell us anything about the kind of summer we can expect. We’re still in the midst of spring, so it’s far too early to say what the months of June, July and August may hold.

Summer ‘heatwave’ speculation

That hasn’t stopped speculation about heatwaves, the warmest summer ever and record temperatures in the media. Some stories cite our three month outlook for contingency planners as proof of the impending heatwave, but this is in no way an accurate reflection of what it shows.

The outlook shows probabilities attached to different scenarios for temperature and rainfall over the whole three-month period it covers. This is useful for those who use probabilities to plan ahead on longer-timescales, but not very useful for deciding where and when to go on your UK summer holiday, for example.

What does the longer outlook show?

Our current three month outlook does show that above average temperatures are more likely than below average temperatures for the April-June period. The outlook is essentially the scientific equivalent of factoring the odds on a horse race and, just like a horse race, the favourite doesn’t always win.

It’s also important to note that above average temperatures over a three-month period could come about in a variety of ways in terms of actual weather – we can still see warmer than average temperatures when it’s cloudy and wet, for example. Also, even in an above average three-months not all individual months would need to be above average.

This just reinforces the point that the contingency planners outlook doesn’t tell us what specific weather we are going to see at a specific location. For the best information on the weather ahead, people should use the Met Office’s 5-day weather forecast supplemented with our 30-day outlook.

By keeping up to date with the latest forecast, you’ll always have the most up-to-date and accurate view of the weather in store for the UK.





UV levels over 2015 Easter holidays

5 04 2015

Updated Tuesday 7 April 2015

At this time of year, despite still feeling quite cool, the sun can be as strong as it is in September. The UK often experiences higher than normal UV levels in April and May as a result of ozone anomalies, where pockets of low ozone move across the UK. This means that there is a higher chance than normal of getting sunburnt in prolonged spells of sunshine.

The main factors affecting the strength of UV radiation reaching the Earth’s surface are:

  • the time of year
  • the latitude
  • the amount of cloud, dust and pollution in the atmosphere
  • the amount of ozone gas in the stratosphere

The first three of these four factors are well-represented in our model, and so for the vast majority of the year, the UV forecast gives excellent guidance. However, the amount of ozone is currently modelled on climatology, i.e. the average concentration for the time of year. The presence of ozone in the stratosphere is important because it absorbs much of the UV radiation before it reaches even the top of the highest clouds in the atmosphere.

Our forecast for UV for this week is indicating generally moderate levels, however there is a possibility that where it is sunny or where the cloud is thin, UV levels may, in fact, be higher than forecast. UV can also be stronger at higher altitudes, so be aware and prepared if hill walking or mountain climbing this week.

If you are in an area that is sunny, make sure you take steps to ensure that you and your loved ones enjoy the sunshine safely, particularly as your skin may not be acclimatised to sunshine after the long winter months.

You can check the current levels of UV on the DEFRA Monitoring pages.

For more information on UV and ozone, visit our learning pages:





Powerful super-typhoon heads for Philippines

1 04 2015

There is currently a super typhoon in the western North Pacific called Maysak. This is a particularly strong storm for the time of year with winds in excess of 160 mph. The strongest storms in this region usually occur between August and October. Tropical storms, including typhoons, are reliant on sea surface temperatures for their energy, and as the northern hemisphere has just moved from winter to spring, this is the coldest time of year for sea temperatures. However, in the region where Typhoon Maysak formed just north of the equator, sea temperatures are almost always above 26°C, which is the critical value for tropical storm formation. Furthermore, the sea temperatures are unusually warm in this area by more than 2°C.

Super Typhoon Maysak is the fourth tropical storm of the season in the western North Pacific, the others being Mekkhala, Higos and Bavi. There has not been a year with four or more tropical storms in this region forming before the end of March since 1965. Three of the four storms have been typhoons – only Bavi remained below the 74mph threshold (the sustained wind speed required to become a typhoon). There have never been as many typhoons before the end of March in the era of reliable records (since World War II). Maysak was also the strongest typhoon to develop in March in this region since Mitag in 2002.

Typhoon Maysak as seen from the MTSAT satellite on 1 April 2015 Image courtesy of digital-typhoon.org

Typhoon Maysak as seen from the MTSAT satellite on 1 April 2015
Image courtesy of digital-typhoon.org

Maysak has now started to weaken as it moves west-northwest towards the Philippines. However, Maysak is still likely to be a typhoon when it makes landfall this weekend. There is still some uncertainty over the exact track of the storm, but the most probable path suggests the Philippines’ northern island, Luzon, is most at risk – including the capital Manila. Wind damage and flooding are likely, particularly in coastal areas.

Typhoon Maysak on 1 April 2015. Image courtesy of the US Naval Research Laboratory

Typhoon Maysak on 1 April 2015.
Image courtesy of the US Naval Research Laboratory

The Eye of the Storm

Air sinks at the centre of a typhoon, resulting in the formation of an ‘eye’ which is sometimes free of cloud and mostly calm. However, on occasions small scale rotations can develop within the eye causing distinctive ‘mesovortices’ (small scale columns of rotating air) in the low level cloud pattern. These can be seen in this satellite loop of Typhoon Maysak created by the Cooperative Institute for Meteorological Satellite Studies at the University of Wisconsin:

http://cimss.ssec.wisc.edu/goes/blog/wp-content/uploads/2015/03/MAYSAK_H8VIS_064_31March_end0600_fast.gif

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 Maysak 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, as well as the latest observed cloud cover and sea surface temperature. We also provide updates on current tropical storms via @metofficestorms on Twitter.





March continues sunny theme for UK

31 03 2015

Following the sunniest winter in records dating back to 1929, March has continued the trend with above average sunshine hours according to early Met Office statistics.

Map showing sunshine hours between 1-29 March compared to the full-month long-term average.

Map showing sunshine hours between 1-29 March compared to the full-month long-term average.

Up to the 29th of the month, there had been 115.0 hours of sunshine which is slightly above the full-month long-term (1981-2010) average of 101.8 hours.

Northern Ireland has been particularly sunny compared to average, with 126.9 hours of sunshine so far this month – which is well ahead of its long-term March average of 97.7 hours.

It has also been a slightly drier than average month up to the 29th, with 80.4mm of rain for the UK so far making up about 85% of the long-term average for the whole month (95.1mm). We’d expect to have had about 94% of the full-month average by this stage of the month.

England has been particularly dry, with the 39.4mm notching up just 62% of the full month average (64.0mm).

Wales and Northern Ireland were also fairly dry (notching up 74% and 78% of their full month average respectively), whereas Scotland is slightly wetter than average – having seen 148.2mm of rain which is just over the full-month average.

When it comes to temperatures – the month has been spot-on average up to the 29th, with a mean temperature of 5.5C.

Looking closer at individual countries, England, Wales and Northern Ireland were all slightly colder than average (by no more than a few tenths of a degree), while Scotland again bucked the trend with slightly above average temperatures (by 0.3C).

Overall the month has been fairly average so far, with no records broken. The final figures are likely to change slightly once the final two days of the month are added.

You can explore Met Office statistics on our UK Climate pages.

UK statistics for 1-29 March:

Mean Temperature Sunshine hours Rainfall  
1-29 March
Actual Diff to Avg Actual % of Avg Actual % of Avg
  degC degC hours % mm %
UK 5.5 0.0 115.0 113 80.4 85
England 6.1 -0.1 122.0 113 39.4 62
Wales 5.4 -0.4 118.7 117 86.1 74
Scotland 4.4 0.3 100.2 108 148.2 105
N Ireland 5.6 -0.2 126.9 130 74.3 78




The Met Office Pollen Forecast goes live

25 03 2015

Different types of pollen, released at varying times throughout the year, cause millions to suffer from hay fever and other allergies and these symptoms can have a serious impact on well-being. The Met Office counts pollen from March to August, however, pollen can be in the air much earlier – from January right through to November.

The pollen season has three main pollen type phases :

  1. Tree pollen – late March to mid-May.
  2. Grass pollen – mid-May to July.
  3. Weed pollen – end of June to September

Our pollen calendar has a detailed breakdown of the different types of pollen and their peak times within a season. We manage the only pollen count monitoring network in the UK using information from our network, our weather data and expertise from organisations such as the National Pollen and Aerobiological Unit and PollenUK to produce forecasts that help support allergy and hay fever sufferers through the most difficult time of the year.

There are millions of hay fever sufferers across the UK, and the Met Office forecasts provide vital information to help reduce the impact pollen has on their health.  At this time of year, tree pollen is more prevalent with grass and weed pollens becoming more prevalent from mid May onwards.

Yolanda Clewlow said: “The best way to manage your condition, if you suffer from hayfever, is to keep an eye on the Met Office pollen forecasts to help you understand the best time to take appropriate medication and avoid exposure to pollen.”

We provide free, public pollen forecasts to all of the UK.

Pollen Diary

As part of an important Europe-wide study, hay fever sufferers are recording their symptoms online through the European Aeroallergen Network (EAN) Patient’s Hay fever Diary.

Document your symptoms and compare them with concentrations of pollen in the air, to help identify which pollen you are allergic to, look back at pollen levels from previous seasons and read the latest pollen news. This is a long-term study that will significantly aid research into pollen and hay fever.

Sign up to the pollen diary.

Pollen Maps

Together with Public Health England we have produced species location maps for the south west of key allergenic plant species (Cornwall, Devon, Somerset). The maps show the locations of six different tree and plant species – grass, alder, ash, birch, oak and pine – key allergenic plants for asthma and hayfever.

The pollen forecasts are part of a range of weather-related services offered by the Met Office, which include UV indexHeat Health watch and data supporting the UK air quality forecasts.

 





What did the solar eclipse look like from space?

20 03 2015

If you were lucky enough to see the solar eclipse this morning, you will have experienced a moment of darkness as the Moon temporarily blocked the Sun’s light from reaching the Earth.

You will have been briefly standing in the Moon’s shadow as it travelled over the surface of the Earth. The shadow moved over the Atlantic Ocean towards the UK, before passing to the north of Scotland and on towards Svalbard, over a period of approximately 4 hours.

During the hours of daylight this shadow was visible from space, and EUMETSAT’s geostationary imaging satellite, Meteosat-10, was perfectly placed to observe it.

Sitting at 0 degrees longitude (the same as Greenwich, London), approximately 35,000km above the Earth, the satellite captures the Sun’s light that is reflected back into space from the Earth’s atmosphere and surface.

It does this using the visible channels of its imaging instrument, SEVIRI. During an eclipse the Moon blocks the path of the Sun’s light rays, leading to an absence of reflected light from the affected part of the Earth. Hence, the SEVIRI imagery observes an anonymously dark patch: the Moon’s shadow.

A SEVIRI image captured during the solar eclipse on 3rd November 2013. The Moon's shadow is centred over the ocean to the south of West Africa.

A SEVIRI image captured during the solar eclipse on 3rd November 2013. The Moon’s shadow is centred over the ocean to the south of West Africa.

How noticeable this dark patch is in the SEVIRI imagery is determined by the atmospheric conditions. Regions of cloud exhibit high albedo (the degree to which light is reflected), and consequently they reflect a great deal of light. The Moon’s shadow will therefore be most noticeable when it passes over cloudy areas.

Land surfaces have a lower albedo, but the reduction in reflected light will still be noticeable to SEVIRI. The ocean surface has the lowest albedo, reflecting only 6% of the Sun’s light. Accordingly, in oceanic regions with clear skies the Moon’s shadow may not be very clear in the satellite imagery.

A SEVIRI image captured during the solar eclipse that occurred on 3rd November 2013 can be seen in the picture on the left, above. At 13:15 GMT the Moon’s shadow was centred over the ocean to the south of West Africa.

The reduction in the brightness of clouds in the region is the most obvious impact of this. The centre of the shadow indicates the region of total eclipse. Moving away from this area the shadow fades, indicating regions that experienced only a partial eclipse.

While cloud cover in some parts of the UK meant that many saw only glimpses of the eclipse, or nothing at all, those same clouds provided a good opportunity to capture some images of the shadow from space.

You can see a loop of imagery from this morning’s eclipse below.





Partial eclipse of the sun

19 03 2015

Friday morning will see a partial eclipse of the sun over the UK. So what does the weather have in store?

Friday Weather

There is expected to be a lot of cloud around for Friday morning. There may be some clearer spells across central England, Wales and the south west England, with a chance of some breaks in the cloud either side of this.

It looks like Southern England, Northern England, Northern Ireland and Scotland will have cloud and this will be thicker the further north you go.

Check out the expected cloud cover in your area on our cloud map.

If you’re interested in seeing the eclipse, it’s worth heading out to take a look regardless of the weather. If it’s cloudy it’ll still get noticeably darker as the moon passes in front of the sun, and you may just get a better look if the cloud thins or a small break in the clouds appears at the right time – but do remember to use appropriate viewing equipment.

Will the Eclipse affect Space Weather?

Earlier in the week we saw the biggest solar storm in 11 years which led to sightings of  the Northern Lights, or aurora borealis, as far south as Somerset.  The solar storm was caused by a large explosion on the Sun on Sunday (15 March) throwing huge amounts of magnetically charged particles into space, called a Coronal Mass Ejection (CME).

The eclipse won’t have an impact on the space weather we experience, however it will give scientists an opportunity to study the corona of the Sun in more detail. The detail within the corona is only visible when the extremely bright light from the Sun is obscured during an eclipse. A number of instruments used for monitoring the Sun for space weather forecasting, such as the LASCO instrument on the SOHO satellite, produce an artificial eclipse by placing an obscurer in front of the solar disc. This produces images like the one below showing a ‘streamer’ to the left of the Sun and a twisted magnetic structure within a coronal mass ejection on the right.

Picture courtesy of NASA

Picture courtesy of NASA

In the image, the position of the Sun is indicated by the white circle, with a larger obscurer blocking out the bright light from the Sun exposing the finer and fainter structures.





Air quality issues in the UK – what’s really going on?

19 03 2015

There has been some media coverage about air pollution issues in the UK today, so what’s really going on?

It is true to say that since Tuesday this week the UK has seen elevated levels of air pollution. This is mainly due to high pressure dominating over the country, which means a lack of wind and atmospheric circulation which would normally disperse pollution.

This allows pollution from things like cars and industry to build up in the lower atmosphere, affecting our air quality. This means much of the pollution we are seeing is due to home-grown sources, but with some contribution of pollution from the continent.

As you can see from the current air quality forecast on Defra’s air quality pages, whilst most areas of the country are seeing moderate or low levels of pollutants today, some areas are seeing high levels.

The situation is improving, however, with air quality levels expected to return to a normal level over the next couple of days.

Levels we have seen over the past few days and today are by no means unusual – we expect to see conditions similar to this several times a year.

The air pollution is also nowhere near record levels – in fact, we saw higher levels than this during a period of poor air quality at about the same time last year.

It’s also worth noting that the current air quality issues don’t fit any scientific definition of smog – which is a term which describes a mixture of smoke and fog.

There’s no fog around at the moment and smoke would only be a tiny fraction of any contribution to the poorer air quality we’re currently seeing.

The main effects of the current conditions will be felt by individuals with existing heart or respiratory conditions, who may experience increased symptoms. More health advice is available online on Defra’s air quality pages.

Throughout the next couple of days, the Met Office will continue to work closely with Defra, Public Health England and Public Health Wales to ensure they have the most up-to-date and accurate air quality forecasts in order to provide relevant advice to the public.








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