When a piece of Sun hits the Earths magnetic field its impact is usually just visible on my magnetometer as a little "nick" in the graph. The size of this impact would suggest a sizable event has taken place and as a result we may be in for a better than "normal" display of aurorae.
These events are notorious to predict and only time will tell what we get. As a guide -
The K value on the top of the graph: values of 5 mean a good display for the north of the country and values of 6 and above mean northern lights for most of Ireland.
The graph: Watch the red graph, displacements of 70nt (1.5 boxes) are needed for displays over most of Ireland.
and of course stay tuned to Surfing the Sun