Prevailing winds mean that Irish airspace maybe closed most of next week, according to weather experts there.

Evelyn Cusack, a Met Eireann forecaster, told the media that said that an area of high pressure which was now south of Greenland meant that northerly winds  would continue to blow over Ireland from Iceland this week.

“The medium-range forecast on Friday suggested that the south-westerly winds would break through by Wednesday or Thursday,” she said. “We want these southerly winds to push the arctic winds and all the ash away, but the latest model shows this won’t happen until Friday or next weekend. So between now and then the major airflow over northern Europe will continue to come down from Iceland.”

More than 1,300 flights to and from Ireland's main airports at Dublin, Cork and Shannon airports have been cancelled since Thursday.The Irish Aviation Authority (IAA) closed Irish airspace until at least 1pm on Sunday after being advised by the Volcanic Ash Advisory Centre in London.

 At least 26 countries have now closed parts of their airspace. Five transatlantic flights touched down in Dublin airport before 6am yesterday, but the other 396 scheduled flights were all cancelled.

Icelandic scientists have warned that the volcano shows no sign of decreasing. “The activity has been quite vigorous overnight, causing the eruption column to grow,” said Magnus Tumi Gudmundsson, an Icelandic geologist. “It’s the magma mixing with the water that creates the explosivity. Unfortunately, there doesn’t seem to be an end in sight.”

Meanwhile officials in the Irish government’splayed down the health risks associated with the volcanic dust. “The European Centre of Disease Control have advised that any dust that does fall in Ireland is likely to be minimal and will not have any serious effect on human health,” said Martin Mullen, assistant secretary in the Department of Transport.

He advised  people with chest or lung diseases to  carry their medication “at all times.”