Space Weather Message Code: ALTK08
Serial Number: 23
Issue Time: 2017 Sep 07 2350 UTC

ALERT: Geomagnetic K-index of 8
Threshold Reached: 2017 Sep 07 2350 UTC
Synoptic Period: 2100-2400 UTC
 
Active Warning: Yes
NOAA Scale: G4 - Severe

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 45 degrees Geomagnetic Latitude.
Induced Currents - Possible widespread voltage control problems and some protective systems may mistakenly trip out key assets from the power grid. Induced pipeline currents intensify.
Spacecraft - Systems may experience surface charging; increased drag on low earth orbit satellites, and tracking and orientation problems may occur.
Navigation - Satellite navigation (GPS) degraded or inoperable for hours.
Radio - HF (high frequency) radio propagation sporadic or blacked out.
Aurora - Aurora may be seen as low as Alabama and Northern California