Volcanic ash from Iceland's Grimsvötn heading for UK and Ireland

A volcanic ash cloud erupting from Iceland's most active volcano is expected to reach the United Kingdom at some time during the early hours of Tuesday morning.

The volcano, which erupted on Saturday, has already shutdown some airspace over Iceland. The cloud is expected to reach Scotland, Northern Ireland and the Republic of Ireland, where President Obama landed this morning on the start of his European tour. Airspace closures are not necessarily certain but flight delays are more than a strong possibility, reports the BBC. Last year another Icelandic eruption at Eyjafjallajokul shut down airspace over parts of northern Europe for more than a week. It was a year ago today when the London Volcanic Ash Advisory Commission declared the eruption to have stopped. At that time the Civil Aviation Authority imposed no-fly zones across many areas of the United Kingdom and Europe. The difference between Grimsvötn and last year's eruption at Eyjafjallajokul is the weather conditions are far more changeable. An intense area of low pressure is currently moving across an area of the north Atlantic between Iceland and the UK dragging air in an anti-clockwise motion towards Ireland and the UK. A geophysicist, Pall Einarsson said the Grimsvotn eruption is not as bad as the one last year. The particles from the plume are larger and these tend to fall to the ground more easily rather than remain airborne and affect flight space. Mr Einarsson said, "It is not likely to be anything on the scale that was produced last year when the Eyjafjallajokull volcano erupted, that was an unusual volcano, an unusual ash size distribution and unusual weather pattern, which all conspired together to make life difficult in Europe."