Strong to Extreme: Geomagnetic K-index of 7 or greater

Space Weather Message Code: WARK07 Serial Number: 43 Issue Time: 2014 Sep 12 2307 UTC

WARNING: Geomagnetic K-index of 7 or greater expected Valid From: 2014 Sep 12 2306 UTC Valid To: 2014 Sep 13 0700 UTC

Warning Condition: Persistence NOAA Scale: G3 or greater - Strong to Extreme

NOAA Space Weather Scale descriptions can be found at www.swpc.noaa.gov/NOAAscales

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.