Volcanic activity in Iceland continues

29 08 2014

The Icelandic Met Office (IMO), who monitor volcanoes in the country, have been reporting increased seismic activity around the Barðarbunga volcano in Iceland since 16 August.

That activity continued with a small fissure eruption being observed some distance from the volcano in the early hours of Friday (29 August). This led to the IMO raising their ‘aviation colour code’ for the Barðarbunga volcano to Red for a few hours.

This has now been lowered back to Orange after further study of the area revealed the eruption is small and activity is decreasing, with no ash emitted. Under the IMO’s codes, Orange means ‘Volcano shows heightened or escalating unrest with increased potential of eruption’.

The volcanic activity has been variable, with the IMO colour code being briefly Red for Barðarbunga on 29 August and also on 23 August before being downgraded back to Orange.

Another nearby volcano, Askja, is currently Yellow on the IMO code, which means ‘Volcano is exhibiting signs of elevated unrest above known background level’.

The IMO will be continually monitoring the region for any further changes – you can see their latest updates on their website.

The Met Office, as one of nine Volcanic Ash Advisory Centres (VAAC) around the world, will continue to keep in close contact with the IMO. The Met Office has responsibility for forecasting the dispersion of ash originating from volcanic eruptions in the North East Atlantic, primarily in Iceland.

The volcanic ash forecasts are used by airlines, the CAA (Civil Aviation Authority) and NATS (National Air Traffic Services) in the UK, as well as aviation organisations around the world, to make decisions on airspace flight management.

Advice will be issued once ash is released into the atmosphere by an eruption and this can be seen on the Met Office’s VAAC pages on our website.

Because the dispersal of any ash would heavily depend on the type and extent of eruption, as well as the prevailing weather and atmospheric conditions at the time, we can’t provide any speculation on where ash may go. If an eruption occurs that releases ash our advice on potential dispersal will be available on our website.

The Met Office will continue to stay in regular contact with the IMO and will keep the CAA fully informed as the UK’s aviation regulator as well as other stakeholders in the UK and abroad.





How will ex-Hurricane Cristobal affect the UK’s weather next week?

27 08 2014

The third tropical storm in the North Atlantic, Cristobal, has been making some headlines about its potential positive impact on us here in the UK – so what’s actually happening?

Cristobal is currently categorised as a hurricane and is currently between Bermuda and northeast Florida in the western Atlantic.

The storm is forecast to move north-east across the Atlantic over the coming days, changing to an ex-hurricane as it moves away from the warmer waters where it formed.

However, unlike ex-Hurricane Bertha which moved straight to the UK and brought strong winds and heavy rain to much of the British Isles, ex-Hurricane Cristobal is set on a very different track.

Instead it is forecast to move towards Iceland, staying well away from the UK as you can see from the forecast pressure chart below.

Forecast pressure chart for 1pm on Sunday 31 August shows ex-Cristobal heading towards Iceland.

Forecast pressure chart for 1pm on Sunday 31 August shows ex-Cristobal heading towards Iceland.

As Cristobal tracks to the north-west of the UK it could bring stronger winds across northwestern parts of Scotland for a time and there will also be some rain moving across the UK on Sunday into Monday.

It will have a longer lasting and more positive impact on our weather, however, as the track of the storm will result in an area of high pressure building further to the south and over the UK.

This high pressure will be maintained through next week as the jet stream moves to the north of the UK, bringing settled conditions across the country.

At this time of the year, high pressure generally brings dry and fine weather with some spells of sunshine, and that’s what we expect to see from around Tuesday next week.

With high pressure, daytime temperatures could reach the low to mid 20’s Celsius in places. This warmth will be especially noticeable following the cool conditions of late.

This spell of warm weather, however, doesn’t fit the definition of an Indian Summer – which you can read about on our website.





Severe weather to affect western France

12 08 2014

A spell of severe weather is expected to affect parts of France overnight and through Wednesday morning as an area of low pressure makes its way in from the Bay of Biscay.

The  area of low pressure highlighted in the satellite image above is expected to deepen and develop before affecting parts of France this evening and overnight.

Pressure chart for 1 am Wednesday 13 August

Pressure chart for 1 am Wednesday 13 August

Forecast rainfall for 1 am Wednesday 13 August

Forecast rainfall for 1 am Wednesday 13 August

 

 

 

This brings the risk of severe thunderstorms across western, then southern France overnight and during Wednesday morning. This will bring the potential for flash flooding and will give squally winds, with disruption to local infrastructure and to holiday makers in the region. Very strong winds and high seas are also likely for a time overnight along the western coastline of France. Meteo France currently has severe weather warnings in force.

 

This area of wind and rain should then move quickly across Switzerland and southern Germany during Wednesday afternoon.





Is Tropical Storm Bertha heading for the UK?

4 08 2014

Update: The latest update about the whether ex-Bertha will affect the UK can be found in our news release

A Tropical Storm called Bertha, which is currently in situated off the east coast of the US, could head towards Europe over the next week – so what’s the outlook?

Forecast tracks for Bertha, which was a hurricane but has now been downgraded to a tropical storm, suggest it will head north – staying offshore from the eastern coast of the US before turning to track east across the Atlantic.

Forecast track for Bertha from StormTracker shows it heading north off the east coast of the US before turning east.

Forecast track for Bertha from StormTracker shows it heading north off the east coast of the US before turning east.

While all forecast models suggest the storm will head in the general direction of UK and continental Europe, there remains a lot of uncertainty about exactly what it will do.

One certainty is that as the storm heads north away from the very warm seas which drive its power, it will lose strength and become what’s known as an extra-tropical storm – so we won’t be seeing a ‘hurricane in Europe’, but there is a chance we could see a fairly active summer storm.

The development of hurricanes and extra tropical storms can present complexities for meteorologists, and Bertha is a good example of that.

Here at the Met Office we use several world-leading forecast models as well as our own, and this gives an indication of how certain a forecast is. If all the models agree, there’s higher certainty, if they diverge, we know the atmosphere is finely balanced and there are several possible outcomes.

Satellite image of Bertha in the Caribbean taken at 11.45am on Monday, 4 August 2014 (Picture from NOAA)

Satellite image of Bertha in the Caribbean taken at 11.45am on Monday, 4 August 2014 (Picture from NOAA)

In the case of Bertha each of the models we use gives a very different picture of what the storm will do. This ranges from Bertha heading towards France as a weak feature which will completely miss the UK, to it arriving as a fairly active summer storm.

In terms of timing, there’s also a spread of possibilities – but it looks likely that the earliest Bertha would affect the UK would be on Sunday or into the start of next week.

As time progresses, different models normally come more in to line with each other and uncertainty decreases. The Met Office will be keeping an eye on how this situation develops over the next few days to give everyone in the UK the best advice on what Bertha is likely to do.

Given the time of year and the potential heavy rain, strong winds and large waves Bertha could bring if it does head to the UK, we’d advise everyone to stay up to date with the latest forecasts and warnings from the Met Office over the next few days.

You can also see the forecast track for Bertha and other tropical storms on our StormTracker pages.

NOTE – story updated to reflect Bertha’s status after being downgraded to a tropical storm.





Thunderstorms bring intense rainfall to parts of England

28 07 2014

This morning has seen some intense downpours across parts of south east England.

They developed across parts of East Anglia in the early hours of the morning, with further areas of heavy showers across Sussex, Surrey, Kent and the south of London following later.

The showers were very heavy in places with thunderstorms, hail, and torrential rain reported, giving high rainfall totals and localised flooding in some areas.

The high rainfall totals were caused by an area of low pressure and a plume of warm air that moved in from the near continent accompanied by light winds, meaning that the showers were slow moving.

Several spots have seen more than half of their average monthly rainfall for the whole of July in just one hour.

Below you can see some of the highest recorded hourly rainfall totals from Environment Agency rain gauges through the morning of Monday 28th July 2014:

Great Dunmow Essex 43 mm (4am to 5am)
Isfield Sussex 37 mm (8.30am to 9:30am)
Ardingly Sussex 35 mm (8.30am to 9:30am)
Santon Downham Suffolk 33mm (4am to 5am)
Weirwood Sussex 28 mm (9am to 10am)
Northolt London 20mm (7am to 8am)

 

The band of showery rain is now easing, but a yellow warning for rainfall remains in place for the south east of the UK as the risk of seeing some further isolated downpours remains.

In addition, the far south east of England could see further persistent and perhaps locally heavy rain later today and overnight, with parts of Kent and Sussex most at risk. Conditions across all areas should then improve through tomorrow.





First half of July is… average?

18 07 2014

With the recent run of generally fine, dry and warm weather you’d be forgiven for thinking this July so far would be anything but average – but the statistics tell a different story.

The UK mean temperature for 1-16 of the month is 15C, just 0.1C above average. UK rainfall is perhaps surprisingly close to the average too, with 36.3mm of rain making up 46% of the whole-month average – we’d expect to see about 52% of the average by now.

Sunshine is the only measure which is notably above average, with 111.4 hours for the UK which is about 65% of the whole-month average (again, we’d expect about 52% at this point in the month).

These figures might not fit in with how many have perceived this month so far, which has seen a good deal of dry and fine weather.

One possible reason for this is that UK day-time maximum temperatures have been slightly higher than average (19.7C), while the night-time minimums have been slightly lower than average (10.4C). So we’ve experienced warmer days, and cooler nights, which adds up to a very average mean temperature (which includes day and night-time temperatures).

Another reason for the statistics bucking the expectation is because, with the exception of last year, the preceding few summers have been generally a little disappointing.

While last year’s July was drier than average, five out of the six previous to that were wetter than average and three were cooler than average.

So perhaps we feel that the recent fine and dry weather is more unusual than it really is because of recent history.

Obviously it’s far too early to judge how this July will finish overall, with half of the month still to add in to the statistics.

You can explore all kinds of climate information, including monthly summaries back to 2001, and climate data back to 1910, on our climate pages.

  Mean temperature Sunshine Rainfall
1 – 16 July 2014 ** Actual Diff from 81-10 average Actual % of 81-10 average Actual % of 81-10 average
  degC degC hours % mm %
UK 15.0 0.1 111.4 65 36.3 46
England 16.3 0.2 120.2 62 29.0 46
Wales 14.7 -0.3 110.6 62 29.5 32
Scotland 13.1 0.0 101.1 72 50.0 50
N Ireland 14.5 0.1 88.1 63 36.7 45

** Please note these are half month statistics from 1-16 July. The final figures will change once statistics from the second half of the month are included.





With hot and humid weather could we see a ‘Spanish Plume’?

15 07 2014

Over the next few days increasingly warm and humid air moving up from the continent will see UK temperatures on the rise, with the warmest days of the year so far expected.

Temperatures in the south east of the country could climb to the low 30s Celsius by Friday, while other parts of England and Wales are likely to see temperatures in the mid to high 20s.

These very warm conditions will be accompanied by a close and humid feel in the air, which could make it feel quite uncomfortably warm in places – particularly during the nights.

While there is a good deal of dry and fine weather in the next few days, there is also the chance of seeing some heavy rain and thunderstorms as we go into the weekend.

Friday may see an area of thundery showers moving north east across parts of England and Wales.

Our meteorologists are also keeping a very close eye on the potential for more widespread thundery downpours on Saturday.

These could develop from what meteorologists call a ‘Spanish Plume’, which is a catchy name for a rather complex set of conditions.

It involves very warm and humid air moving up from the Spanish plateau to the UK. If this meets cooler air from the Atlantic, the warm air can be forced rapidly upwards to produce thunderstorms.

There are a number of ingredients that all have to come in to place for this to happen, however, so the risk of disruption from any heavy, thundery downpours is low for Saturday at the moment rather than a certainty. A yellow alert has been issued for this risk and will be updated in the coming days.

You can keep up to date with how this situation develops by checking our forecasts and warnings over the next few days.

Interestingly, the warm weather we’re expecting can be traced back to the jet stream, a narrow band of fast moving winds high up in the atmosphere which forms where cooler air from the polar region meets warmer air from the tropics.

The jet stream has dipped south over north eastern parts of the US, allowing cooler air to flood in over the area and bringing much lower temperatures than usual for this time of year.

New chart v1

Top image shows forecast jet stream at 1am Wednesday, with an obvious kink over the NE of the US. The bottom forecast image, for 1am on Saturday, shows a kink now over Spain, with warm air from that region flowing towards the UK.

This kink in the jet stream causes a knock-on effect which pushes the cooler air south across the Atlantic, which in turn pushes the warm humid air over the continent (around Spain) towards the UK later this week.

This provides yet further proof of the way in which all weather is connected, but there are no hard and fast rules as to how events in one part of the world will affect us here in the UK.





Early figures suggest one of the warmest Junes on record

27 06 2014

Early statistics from the Met Office National Climate Information Centre show that this has been one of the warmest Junes in records dating back to 1910.

Based on figures up until 25 June the mean temperature for the UK for the month is 14.4 °C, making it joint 6th at the moment and more than likely one of the top ten warmest once final figures are in. The warmest June on record is 1976 with 15 °C.

This continues a run of seven months where the UK mean temperature was warmer than average, with all the months from December through to April each being at least 1 °C warmer than the long-term average.

Looking at specific countries it is currently the second warmest June on record in Scotland with 13.2 °C – the warmest being 1940 with 13.5 °C. For England, Wales and Northern Ireland it’s currently the 9th warmest.

Rainfall totals have been below normal as a whole and sunshine totals have been near normal, brightest over south-west England and Wales but duller over Scotland.

  Mean temperature Sunshine Rainfall
1 – 25 June 2014 ** Actual Diff from 81-10 average Actual % of 81-10 average Actual % of 81-10 average
  degC degC hours % mm %
UK 14.4 1.4 161.1 95 45.9 63
England 15.2 1.2 184.3 101 33.0 53
Wales 14.2 1.0 203.1 117 43.9 51
Scotland 13.2 1.9 113.6 76 67.0 75
N Ireland 14.0 1.2 146.8 98 50.5 66

** Please note these are preliminary statistics from 1-25 June. The final figures will change once statistics from the final few days of the month are included.





Early figures suggest third warmest spring on record

30 05 2014

Early statistics from the Met Office National Climate Information Centre show that this has been one of the warmest springs in records dating back to 1910.

Based on figures up until 28 May and then assuming average conditions to the end of the month, the mean temperature for the UK for the season is 8.97 °C, third warmest in the records (beaten by 2007 with 9.05 °C and 2011 with 9.15 °C).

Looking at specific countries, it is currently the third warmest spring for England, Wales and Northern Ireland.

However, it has been particularly warm in Scotland compared to average. Depending on temperatures in the final three days of May, this spring could be Scotland’s warmest since records began with a current mean temperature of 7.63 °C, just above the record set in 2011 of 7.61 °C.

Each of the three months of spring have seen above average temperatures. The figures for May up to the 28th of the month show it has been 0.8 °C above the long-term average for the UK.

This continues a run of six months where the UK mean temperature was warmer than average, with all the months from December through to April each being at least 1 °C warmer than the long-term average.

Apart from the above average temperatures, statistics for May otherwise show it has been duller and wetter than average so far.

Sunshine is down compared to the long-term average, with the UK having seen 141.8 hours which is 76% of what we would normally expect.

Scotland and Northern Ireland have seen particularly low levels of sun – Scotland has seen 103.8 hours which is 58% of the average, and Northern Ireland has seen just 51% of its average with 92.9 hours.

Rainfall statistics for May show that it has been a wet month so far, with the UK having seen 97.7mm of rain which is 140% of the long-term average.

When it comes to rainfall for spring overall, it has been only slightly wetter than average. The figures show that spring is about 7% wetter than the long-term average.

Northern Ireland actually had a slightly drier spring, with only 91.8% of the average rainfall.

 

Mean Temperature Rainfall
Spring* Actual Diff from Avg Actual % of Avg
degC degC mm %
UK 8.97 1.23 255.1 107
England 9.76 1.24 201 111
Wales 9.04 1.03 295.5 101
Scotland 7.63 1.3 339.8 107
N Ireland 9 1.12 222.7 92

*Please note these are projected numbers that include statistics from 1 March to 28 May, then assume average conditions for the final few days of the season. They may not accurately represent the final full-season figures.

 

Mean Temperature Sunshine hours Rainfall
May** Actual Diff from Avg Actual % of Avg Actual % of Avg
degC degC hours % mm %
UK 11.1 0.8 141.8 76 97.7 140
England 12 0.8 170.6 90 91.1 156
Wales 11.1 0.5 138 74 124.2 145
Scotland 9.7 0.9 103.8 58 102.9 122
N Ireland 11.2 1 92.9 51 90.1 124

** Please note these are preliminary statistics from 1-28 May. The final figures will change once statistics from the final few days of the month are included.





Rain over the Bank Holiday Weekend, with more to come

27 05 2014

The Bank Holiday weekend saw a good deal of dry and bright weather in places, but there was also heavy rainfall in some spots over the three days with some significant rainfall totals.

Much of England and Wales had a wet Saturday as rain pushed northwestwards with heavy, and thundery showers following.

Sunday brought heavy showery rain to western and northern parts of the UK, with 25 mm of rain falling in three hours around the Edinburgh area.

Heavy rain pushed in from the southeast on Bank Holiday Monday, whilst to the west and north of this there was some sunny weather, but also heavy and thundery showers for Cornwall, Northern Ireland and Scotland.

Here are the highest UK rainfall totals for each of the three days of the Bank Holiday:

 

Rainfall totals from 0900 Saturday 24 May – 0900 Sunday 25 May
Site Area Amount (mm)
Liscombe Somerset 32.2
Usk Monmouthshire 29.0
Tredegar Gwent 23.4
Okehampton Devon 22.5
Waddington Lincolnshire 22.0
Sheffield South Yorkshire 22.0

 

Rainfall totals from 0900 Sunday 25 May – 0900 Monday 26 May
Site Area Amount (mm)
Edinburgh, Gogarbank Midlothian 26.2
Cardinham Cornwall 17.8
Edinburgh, Royal Botanic Garden Midlothian 17.4
Tyndrum Perthshire 17.2
Camborne Cornwall 14.2

 

Rainfall totals from 0900 Monday 26 May – 0900 Tuesday 27 May
Site Area Amount (mm)
Wattisham Suffolk 31.2
Brooms Barn Suffolk 25.4
Cavendish Suffolk 21.8
Charsfield Suffolk 19.2
Cambridge Cambridgeshire 17.0

 

Looking ahead through the rest of this week there is more rain to come, particularly for eastern and northeastern England, while Scotland (especially the north) has the best of the warm, sunny weather.

Suffolk has already seen heavy rainfall through Tuesday morning with over 30 mm of rainfall at Wattisham through the first 9 hours of the day.

This is going to push northwards through Tuesday into Norfolk and Lincolnshire. A Met Office yellow warning has been issued to warn of rainfall amounts reaching around 30mm in some spots which could lead to some localised flooding.

There are also going to be some heavy showers over southern parts of Wales and parts of the West Country.

Wednesday will again be wet for many, especially around northeast England with parts of Yorkshire at risk of over 30 mm, for which another yellow rainfall warning has been issued. With strengthening winds this will make it feel quite unpleasant at times.

More showers or longer spells of rain are expected for Thursday, before things should turn generally drier, brighter and warmer by the weekend.








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