Last updated: 1328 BST on Wednesday, 21 April 2010
The Met Office acknowledges the decision by the CAA and the aviation industry to change the engine tolerance levels for the safe levels of ash ingestion into aircraft engines.
The Met Office is the north-west European Volcanic Ash Advisory Centre with responsibility for issuing the Volcanic Ash Advisories for this area in line with internationally agreed standards and processes as designated by the aviation regulator and industry.
We will now provide timely advice to NATS about the dispersion of the volcanic ash in line with the new engine tolerance criteria.
Eruptions from Eyjafjallajökull have continued through today with debris being emitted to around 13,000 ft. Weather patterns continue to blow new areas of ash towards north-western parts of the UK, but ash over other parts of Britain and Europe should gradually disperse during the afternoon and evening.
The Met Office uses multiple dispersion models endorsed by the international meteorological community. The output from the Met Office volcanic ash dispersion model has been compared with our neighbouring VAACs in Canada and France since the beginning of this incident and the results are consistent.
Our models are confirmed by observations which have seen ash in the UK and south of England. These include:
The Met Office is unable to advise of any details of any flights. However, many airlines are providing information on their websites.
Regular updates from our forecasters.
Information for our customers
Supporting you through the event.
Frequently asked questions and glossary about the volcano.
Useful links and contacts
How to find out more about roles and responsibilities.
The volcano as it develops
Movies showing the changing nature of the volcano
A selection of images about the eruption
Hear from our experts
Our experts explain more about modelling the effects of the volcano
As one of only two World Area Forecast Centres, we regularly advise the UK Civil Aviation Authority (CAA) and National Air Traffic Services.
Our forecasters monitor volcanic eruptions as part of the Met Office's role in the global network of nine Volcanic Ash Advisory Centres.
Volcanic ash can be dangerous for aircraft, causing damage, reducing visibility, and potentially clogging engines.
Our Environment Monitoring and Response Centre is constantly monitoring the Iceland area. Our first advisory was issued at 1400 on 14 April and they have subsequently been updated every six hours.
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