This was more than your every day garden variety CME. The geomagnetic Kp index went from
less than 2 to about 6 (from very quiet to very stormy) in less than 5 minutes. These
type of sudden commencement storms are not common even during active solar
periods. That is why I posted a special notice on it last night within minutes of
it's occurrence - I felt there was uncommon danger associated with this CME.

• Space weather data