Space Weather Message Code: ALTK04
Serial Number: 1974
Issue Time: 2017 Apr 21 1642 UTC
ALERT: Geomagnetic K-index of 4
Threshold Reached: 2017 Apr 21 1638 UTC
Synoptic Period: 1500-1800 UTC
Active Warning: Yes
NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents – Weak power grid fluctuations can occur.
Aurora – Aurora may be visible at high latitudes such as Canada and Alaska.