WATCH: Geomagnetic Storm Category G3

Space Weather Message Code: WATA50 Serial Number: 59 Issue Time: 2015 Dec 30 2136 UTC

WATCH: Geomagnetic Storm Category G3 Predicted Highest Storm Level Predicted by Day: Dec 31: G3 (Strong) Jan 01: G1 (Minor) Jan 02: None (Below G1)

THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT

NOAA Space Weather Scale descriptions can be found at www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 50 degrees Geomagnetic Latitude. Induced Currents - Power system voltage irregularities possible, false alarms may be triggered on some protection devices. Spacecraft - Systems may experience surface charging; increased drag on low Earth-orbit satellites and orientation problems may occur. Navigation - Intermittent satellite navigation (GPS) problems, including loss-of-lock and increased range error may occur. Radio - HF (high frequency) radio may be intermittent. Aurora - Aurora may be seen as low as Pennsylvania to Iowa to Oregon.