HUNDREDS more flights across Europe were cancelled yesterday due to the volcanic ash cloud as disruption spread to Germany, Switzerland and into the North Atlantic.
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Three airports in the Western Isles remained closed until 7pm, but Glasgow airport handled thousands of extra passengers after nearly 30 flights were diverted from Iceland.
The Scottish Government said airspace over the country was expected to stay clear over the next few days, but warned of potential further disruption if activity from the Eyjafjallajkull volcano in Iceland increased.
Several dozen Scottish flights were grounded yesterday, including ones between Edinburgh and Berlin, Geneva, Lisbon, Milan and Paris.
Stornoway, Benbecula and Barra airports were closed from 7am to 7pm, with Inverness, Wick and Kirkwall shut from 7am to 1pm. Prestwick-Derry flights were also cancelled.
Some transatlantic flights were delayed by several hours. Aircraft had to fly further north than normal to avoid the cloud. Some transatlantic flights are being re-routed as far south as the Canary Isles, off Africa.
However, Glasgow airport was about one fifth busier than usual, with 3,500 additional passengers, after Icelandair relocated its transatlantic hub to Scotland because Iceland's main airport was closed by the ash cloud.
A total of 28 Icelandair flights operated from Glasgow. There were also feeder flights from Akureyri airport on the north coast of Iceland, while the main airport at Keflavik, in the west, was shut.
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At least three British Airways flights were also diverted via Glasgow to refuel.
Transport minister Stewart Stevenson said the Scottish Government resilience room cabinet sub-committee met yesterday and would continue to meet for several days "to ensure we are fully prepared to respond to changing circumstances".
He said: "We welcome the fact the majority of flights in and out of Scotland are flying as planned with limited disruption.
"There has been an inconvenience to some passengers travelling from airports in the far north and isles, and those travelling to and from some parts of Europe, but I'm sure they will appreciate that safety comes first.
"Volcanic activity has calmed and we expect Scotland's skies to remain clear over the next few days. But conditions are volatile and the picture is fluid."
The Met Office said: "Explosive activity from the Eyjafjallajkull volcano has continued to decrease and the ash plume has reduced slightly in height to 18,000-20,000ft.
"The Icelandic Met Office state there are no signs that the eruption is about to end, with the situation with the volcanic eruption remaining dynamic. Winds are expected to blow from a mainly northerly direction into Monday, with most of the ash cloud likely to stay over the Atlantic Ocean and close to western parts of the British Isles."
Eurocontrol, which co-ordinates air traffic control across the continent, said some 500 flights were expected to be cancelled yesterday – around 2 per cent of the total.
A spokesman said: "Ash eruptions are still substantially affecting European airspace, in particular between the ground and 20,000 feet.
"Airports in the north and centre of Portugal have been affected, as have airports in north-western Spain. Airports in the Milan area were unavailable due to airspace closures until midday, and Pisa and Florence airports were also closed.
"During the day, it is expected the area affected by the ash cloud will shrink and most of the airports that are currently closed are expected to open later. Transatlantic flights continue to be affected by the ash cloud. Flights are required to make significant rerouting to avoid the area of ash cloud coverage. This is leading to some delays."
Forecaster Rachel Vince, from MeteoGroup, said: "The volcano appears to still be erupting but there is a north-easterly wind between the UK and Iceland so the ash is being kept away from the British Isles. As the ash gets to a lower level it is being blown by a westerly wind towards southern Europe."
The Nordic Volcanological Centre at the Institute of Earth Sciences in Iceland said the eruption was "still in a strong explosive phase".
A spokesman for National Air Traffic Services, which is responsible for controlled UK airspace, said: "The high density area of the volcanic ash cloud is now lying to the north-west of the UK.
"As a result, there are currently no restrictions within UK airspace apart from those affecting Stornoway, Benbecula and Barra airfields."
Organisers of the Cannes Film Festival, which opens on Wednesday, were waiting to see whether it would be affected.
However, the Vatican said the Pope's visit to Portugal tomorrow should not be disrupted.