Typhoon heads for Japanese volcano

23 08 2015

Typhoon Goni, which was located just east of Taiwan on Sunday morning, is expected to track across the western side of Kyushu Island in SW Japan through Monday.  There is a risk it could bring up to 200mm of rainfall in 24 hours across Kyushu, leading to a risk of flooding and landslides along with the threat of Hurricane Force winds and a storm surge.  This comes as the Japanese Meteorological Agency issues a level 4 alert for a major volcanic eruption on Mount Sakurajima.

Mount Sakurajima is one of 16 ‘Decade Volcano’ around the globe, meaning that it is a potentially destructive volcano close to populated areas. The level of alert suggests that the local population should prepare for evacuation, which would be made more difficult by a Typhoon impact.

Satellite image courtesy of National Oceanic and Atmospheric Administration

Satellite image courtesy of National Oceanic and Atmospheric Administration

Typhoon Goni has already bought heavy rainfall and Typhoon strength winds across the NE tip of Luzon in the northern Philippines.  Goni is expected to remain a Strong Typhoon (equivalent of a Category 2 Hurricane) with sustained winds of 80 knots and gusts to 115 knots, tracking steadily north through the rest of Sunday and Monday across the eastern East China Sea.  There is a risk of a storm surge and coastal flooding up through Kagoshima Bay in southern Kyushu.

Once Goni passes across western Japan, it is likely to lose its tropical characteristics, but could still bring flooding rains to the Korean Peninsula on Tuesday.


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.

Five things you might not know about thunderstorms

20 03 2013

1. Lighting can strike twice. The empire state building in New York has been struck by lightning as many as 48 times in one day.
2. The average flash of lightning would light a 100 watt light bulb for three months.
3. Lightning can strike in volcanic ash clouds. Not much is known about volcanic lightning, but we’re using it to help track ash clouds.

Volcanic lightning

Volcanic lightning

4. Thunderstorms can trigger asthma. The Met Office has worked with the NHS and Asthma UK to try and understand why.
5. The most thundery part of the earth is the island of Java where the annual frequency of thunderstorms is about 220 days per year.

Volcanic Ash Guidance ceases from Met Office as Iceland Volcano remains ‘paused’

29 05 2011

Latest information received from the Icelandic Meteorological Office indicate that the volcanic activity in Iceland has paused.

As a result of this lower activity, UK airspace is not expected to be affected by any further ash cloud and the Met Office will no longer issue Volcanic Ash Guidance from the VAAC.

Volcanologists and Geologists term this quieter spell of volcanic activity as a “paused” phase. However, it is typical for a volcano like this to have several “pauses” as part of its overall eruption phase. Only when the volcano has been “paused” for three months will it then be regarded as being dormant.

Although no ash cloud is being emitted at the moment, while any volcanic activity continues the Met Office will continue to monitor the situation.

Grímsvötn ash cloud – better news for the Bank Holiday

25 05 2011

Latest information received from the Icelandic Meteorological Office (IMO) indicates that the Grímsvötn volcano is no longer emitting ash, and only minor steam plumes from the crater up to around 300 metres. According to the British Geological Survey (BGS), the volcano is still active with on-going low level seismic activity reported, even though this has decreased.

Our advice for today is that the ash has now moved away from the UK toward the continent. Further ahead, Met Office latest volcanic ash cloud advice is that we continue to be in an improving situation and it seems likely that there will only be minimal ash over the UK and Europeas we enter the Bank Holiday weekend. CAA and NATS together with the individual airlines can advise how this improving picture will affect flights.

The movement of the ash cloud will depend on whether we see any further volcanic eruptions and how weather patterns develop. The Met Office London VAAC continues to provide forecast guidance up to 24 hours ahead to support decision-making.

Met Office volcanic ash cloud advice is based on a combination of model output, satellite data and other information from radar, lidar and aircraft. Model information is validated using this observational data and is routinely modified to provide the best advice possible.

Grimsvötn Volcano Latest

25 05 2011

Latest information received from the Icelandic Meteorological Office (IMO) indicates that the Grimsvötn volcano is no longer emitting ash, only minor steam plumes from the crater up to 300 meters.

According to the British Geological Survey (BGS), the volcano is still active with on-going low level seismic activity reported, even though this has decreased. This means it is still possible that further ash emissions may occur at anytime.

As a result, the UK Met Office will continue to receive information from the IMO and BGS on whether the eruption may – or may not – continue.

Met Office in the Media: 09 February 2011

9 02 2011

Defence Codex, the MoD magazine for defence engineering and science has written two articles in the latest edition of the magazine looking back at the Iceland volcanic eruption from last spring. ‘Ash in the sky causes eruption of scientific support‘ looks at how scientists across the Mod, including the Met Office met the challenges of such an unprecidented incident.  The second article ‘Met Office model adapts to crisis‘ explored how our modeling capability was used through the incident, looking also at ongoing research and development.

Coincidentally, there have been reports in some media today. The Telegraph for example reports today ‘Icelandic volcano ‘set to erupt’‘, whilst the Daily Mail says ‘Not again! Icelandic volcano set to erupt dwarfing last year’s devastation, warn scientists‘.  Despite these recent reports, there is currently little evidence to support an assessment of an increased risk of a volcanic eruption in Iceland. The Icelandic Met Office is the mandated State Volcano Observatory and with whom the UK Met Office is in regular contact. They confirm that whilst there was a ‘seismic swarm’ in the north-west part of Vatnajökull on Sunday, this has since died down and there is now no unusual seismic activity in the area. No warnings were or have been issued and the situation across Iceland, as always, is being closely and continually monitored.

Volcanic lightning could help monitor volcanic ash

11 12 2010
Volcanic material thrust high into the atmosph...

Volcanic lightning (Source: Wikipedia)

Met Office researchers have published new findings in ERL suggesting that the amount of lightning produced near a volcano each hour is roughly proportional to the plume height. They believe that the technique could ultimately be used to monitor volcanoes in remote locations or those that are obscured by rain.

To assess the number of lightning strokes the team used ATDnet, the UK Met Office‘s long-range lightning-location network, which has recently been updated.

“ATDnet is used to monitor thunderstorms over a vast area of the world extending from the US to China and the Arctic to the South Atlantic, centred over the UK,” siad Alec Bennett of the Met Office. “Lightning emits powerful electromagnetic pulses over a broad frequency range creating both the bright flash seen by an observer and the crackles on a nearby radio. The peak energy of this emission is found in the very low frequency (VLF) radio band at about 10 kHz, and it is this part of the spectrum that ATDnet uses to locate lightning, utilizing sensors positioned across Europe and beyond.”

The system has previously located lightning from volcanic plumes in southern Chile and earlier eruptions in Iceland. “The availability of quantitative observations of volcanic lightning is sparse, so our results are hoped to add new and detailed observational data to this research field,” said Bennett. “The eruption of Eyjafjallajökull in April–May 2010 provided an excellent opportunity for us to study both the performance of ATDnet after recent network upgrades and to use the lightning data to learn more about the relationship between volcanic activity and plume electrification, a process recognised for decades but still subject to ongoing scientific debate.”

Bennett and colleagues from the UK Met Office and Icelandic Meteorological Office found that plumes from Eyjafjallajökull that reached about 5 km above sea level generated lightning strong enough to be detected by ATDnet. Above this threshold, the rate of lightning production was approximately proportional to the plume height.

“Perhaps most importantly, it was found that this relationship did not exist all of the time, with some plumes higher than 5 km producing no lightning capable of being detected by ATDnet at all,” said Bennett. “This presents us with a unique case study whereby we have several days where a tall plume was not strongly electrified followed immediately by several days of strong electrification, enabling more research to be undertaken on the cause of vivid volcanic lightning displays.”

An eruption of Iceland’s Eyjafjallajökull volcano in late-March 2010 produced a large plume of ash and considerable disruption to flights across Europe.

The team used C-band radar data from the Icelandic Meteorological Office to quantify the plume height above the volcano. This allowed the scientists to combine detailed observations on lightning and plume height as well as modelled atmospheric parameters, such as wind speed, wind direction and ambient temperature. “With these data we can begin to quantify the effect of plume and atmospheric conditions on the generation of volcanic lightning,” said Bennett.

“By comparing the distance between the vent and lightning strokes it was also possible to gain evidence that a charging mechanism was present away from the vent, with many lightning strokes produced several kilometres downwind from the vent,” he added. “This finding suggests that two different charging mechanisms may be present in the plume, one immediately adjacent to the vent – producing numerous weak lightning strokes visible to an observer nearby but not strong enough to be detected by ATDnet – and a further strong charging mechanism operating within the plume, generating lightning with peak currents of at least 3 kA and detected by ATDnet.”


4 11 2010

The Iceland Met Office has informed the Met Office of a Glacial Outburst in or around the Grimsvötn volcano on Iceland.

It is important to note that a Glacial Outburst is NOT an eruption, but is only potentially a pre-cursor to any activity.

Latest information from the Iceland Met Office is that there are no detectable signs of the beginning of a volcanic eruption at Grimsvötn.

Met Office in the Media: 20 August 2010

20 08 2010

The sun reports today on an ‘upside-down’ rainbow that was seen in Derbyshire. What was actually observed is known as circumzenithal arc.  In order for conditions to be right for a circumzenithal arc to form, small, flat, six-sided ice crystals must be suspended high in the sky to create a field of tiny prisms. The sun’s rays enter the ice crystals and is refracted, projecting an arc in the sky which, if complete, would circle the zenith. Completely circular circumzenithal arcs are rare, however; most of them only take up a section of the sky.

Bob Ward, Policy and Communications Director at the Grantham Research Institute on Climate Change and the Environment at the London School of Economics and Political Science writes in the Guardian today about how climate sceptics mislead the public over hacked emails inquiry.

It’s another weekend full of events as well with the V-Festival taking place at Hylands Park  and at Weston Park. You can get forecasts for both locations through the weekend, along with information for the Edinburgh Festival from our events calendar at http://www.metoffice.gov.uk/public/pws/events/

Reuters reports on how airline experts are to assess volcano risks in Iceland in a meeting to take place in September. The meeting taking place in Keflavik will include support from the Met Office as the Volcanic Ash advisory Centre with responsibility for Icelandic Volcanoes.


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