If you look at the latest predictions from the met office
http://metoffice.com/aviation/vaac/d...1271398735.png
You can see that the cloud is starting to move up it's own backside. This will continue until we start getting some SW airflow which, if you look at this chart.
Mean sea level pressure, wind speed at 850 hPa and geopotential 500 hPa, temperature at 850 hPa
is unlikely to occur until next weekend.
We have the real possibility of a massive cloud of ash sitting right over the UK and extending well beyond 10 west.