ALERT: Geomagnetic K-index of 6 Threshold

Space Weather Message Code: ALTK06 Serial Number: 387 Issue Time: 2015 Dec 20 2344 UTC ALERT: Geomagnetic K-index of 6 Threshold Reached: 2015 Dec 20 2343 UTC Synoptic Period: 2100-2400 UTC Active Warning: Yes NOAA Scale: G2 - Moderate

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

Potential Impacts: Area of impact primarily poleward of 55 degrees Geomagnetic Latitude. Induced Currents - Power grid fluctuations can occur. High-latitude power systems may experience voltage alarms. Spacecraft - Satellite orientation irregularities may occur; increased drag on low Earth-orbit satellites is possible. Radio - HF (high frequency) radio propagation can fade at higher latitudes. Aurora - Aurora may be seen as low as New York to Wisconsin to Washington state