This was a false alarm. From the Aurorawatch team:
We are very sorry for today's false alert which was due to man-made disturbance at our Lancaster field site.
Regards,
the AuroraWatch team.
Original alert issued today:
Issued by Aurorawatch UK:
AuroraWatch Alert, 11:07 UT 28 Oct 2009:
VERY LARGE increase in local activity, possible SSC.
http://www.dcs.lancs.ac.uk/iono/aurorawatch/