As well as a greater spread, the ash cloud is also reaching higher into the atmosphere – currently up to nine kilometres – which will continue to affect aviation. All domestic flights have been cancelled until further notice and there are delays and alterations to international flights.
Volcanic ash falls on Reykjavik, citizens fail to notice | IceNews - Daily News
The higher the cloud the further it seems to travel.
I don't know if it will affect UK/Ireland, based on this -
Metcheck.com - Atlantic Jet Stream Forecast - [Updated on 15 May 2010 at 10:00] - Weather Feeds - Live Data - Long Range Weather Forecasts