Space Weather Message Code: ALTK05 Serial Number: 1172 Issue Time: 2017 Sep 28 1007 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2017 Sep 28 1007 UTC Synoptic Period: 0900-1200 UTC Active Warning: Yes NOAA Scale: G1 – Minor NOAA Space Weather Scale descriptions can be found at www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude. Induced Currents – Weak power grid fluctuations can occur.

Space Weather Message Code: WARK06 Serial Number: 406 Issue Time: 2017 Sep 28 0822 UTC EXTENDED WARNING: Geomagnetic K-Index of 6 expected Extension to Serial Number: 405 Valid From: 2017 Sep 27 2012 UTC Now Valid Until: 2017 Sep 28 1500 UTC Warning Condition: Persistence 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 –

Space Weather Message Code: ALTK07 Serial Number: 111 Issue Time: 2017 Sep 28 0805 UTC ALERT: Geomagnetic K-index of 7 Threshold Reached: 2017 Sep 28 0805 UTC Synoptic Period: 0600-0900 UTC Active Warning: Yes NOAA Scale: G3 – Strong 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

Space Weather Message Code: ALTK06 Serial Number: 452 Issue Time: 2017 Sep 28 0749 UTC ALERT: Geomagnetic K-index of 6 Threshold Reached: 2017 Sep 28 0749 UTC Synoptic Period: 0600-0900 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

Space Weather Message Code: ALTK05 Serial Number: 1171 Issue Time: 2017 Sep 28 0636 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2017 Sep 28 0635 UTC Synoptic Period: 0600-0900 UTC Active Warning: Yes NOAA Scale: G1 – Minor NOAA Space Weather Scale descriptions can be found at www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude. Induced Currents – Weak power grid fluctuations can occur.

Space Weather Message Code: ALTK07 Serial Number: 110 Issue Time: 2017 Sep 28 0600 UTC ALERT: Geomagnetic K-index of 7 Threshold Reached: 2017 Sep 28 0559 UTC Synoptic Period: 0300-0600 UTC Active Warning: Yes NOAA Scale: G3 – Strong 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

Space Weather Message Code: WARK07 Serial Number: 73 Issue Time: 2017 Sep 28 0537 UTC WARNING: Geomagnetic K-index of 7 or greater expected Valid From: 2017 Sep 28 0536 UTC Valid To: 2017 Sep 28 0900 UTC Warning Condition: Onset NOAA Scale: G3 or greater – Strong to Extreme 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

Space Weather Message Code: ALTK06 Serial Number: 451 Issue Time: 2017 Sep 28 0509 UTC ALERT: Geomagnetic K-index of 6 Threshold Reached: 2017 Sep 28 0508 UTC Synoptic Period: 0300-0600 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

Space Weather Message Code: ALTK05 Serial Number: 1170 Issue Time: 2017 Sep 28 0412 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2017 Sep 28 0411 UTC Synoptic Period: 0300-0600 UTC Active Warning: Yes NOAA Scale: G1 – Minor NOAA Space Weather Scale descriptions can be found at www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude. Induced Currents – Weak power grid fluctuations can occur.

Space Weather Message Code: ALTK06 Serial Number: 450 Issue Time: 2017 Sep 28 0303 UTC ALERT: Geomagnetic K-index of 6 Threshold Reached: 2017 Sep 28 0259 UTC Synoptic Period: 0000-0300 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