Interplanetary Shock Arrived at ACE - Geomagnetic Disturbance in Progress

An interplanetary shock was detected at the ACE spacecraft December 21st at approximately 1824 UTC (1:24 p.m. EST).  This shock is believed to be associated with the coronal mass ejection from December 18th.  Active to minor storm (G1 - Minor) conditions followed and are expected to persist through the end of December 22nd. You'll find the latest aurora predictions at http://www.swpc.noaa.gov/products/30-minute-aurora-forecast