Yeah it's a pretty exciting period in terms of space weather due to a solar flare released a few days back. Unfortunately it may be that the solar winds have swerved around the Earth rather than as directly as hoped. The CME hit has been slower than predicted, just entering our atmosphere in the last hour or so. It is impossible with aurora to predict it until it actually arrives but it seems tonight's initial forecasts and hype of KP7-9 might not come through (this is an extremely rare forecast). Depending on where you are in the UK, you may be lucky to pick up something faint on the horizon around 2200-0100ish, or maybe even later. I'm on the far north coast of Scotland and will be going out from 10pm onwards due to rare clear skies, so it might be worth a peek if you're around since the Stargazer programme has everyone buzzing!
http://www.swpc.noaa.gov/Aurora/globeNE.html I reckon tonight we may see KP5 at most. If you are on or above that line, you have a good chance. I'd love to be proven wrong and for everyone to see it. It so special.