Space Weather Message Code: WATA30 Serial Number: 167 Issue Time: 2017 Sep 11 1921 UTC WATCH: Geomagnetic Storm Category G2 Predicted Highest Storm Level Predicted by Day: Sep 12: None (Below G1) Sep 13: G2 (Moderate) Sep 14: G1 (Minor) 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 55 degrees Geomagnetic Latitude. Induced

Space Weather Message Code: WATA30 Serial Number: 166 Issue Time: 2017 Sep 11 1147 UTC WATCH: Geomagnetic Storm Category G2 Predicted Highest Storm Level Predicted by Day: Sep 11: None (Below G1) Sep 12: None (Below G1) Sep 13: G2 (Moderate) 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 55 degrees Geomagnetic Latitude.

Space Weather Message Code: ALTK04 Serial Number: 2003 Issue Time: 2017 Sep 11 0110 UTC ALERT: Geomagnetic K-index of 4 Threshold Reached: 2017 Sep 10 2359 UTC Synoptic Period: 2100-2400 UTC Active Warning: Yes NOAA Space Weather Scale descriptions can be found at www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude. Induced Currents – Weak power grid fluctuations can occur. Aurora – Aurora may be

Space Weather Message Code: WARK04 Serial Number: 3312 Issue Time: 2017 Sep 10 2341 UTC WARNING: Geomagnetic K-index of 4 expected Valid From: 2017 Sep 10 2340 UTC Valid To: 2017 Sep 11 1800 UTC Warning Condition: Onset NOAA Space Weather Scale descriptions can be found at www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude. Induced Currents – Weak power grid fluctuations can occur. Aurora

Space Weather Message Code: WATA30 Serial Number: 165 Issue Time: 2017 Sep 09 1507 UTC CANCEL WATCH: Geomagnetic Storm Category G2 Predicted Cancel Serial Number: 164 Original Issue Time: 2017 Sep 08 2049 UTC Comment: Conditions no longer warrant this Watch. 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

Space Weather Message Code: ALTK05 Serial Number: 1154 Issue Time: 2017 Sep 09 0004 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2017 Sep 08 2359 UTC Synoptic Period: 2100-2400 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: 398 Issue Time: 2017 Sep 08 2049 UTC EXTENDED WARNING: Geomagnetic K-Index of 6 expected Extension to Serial Number: 397 Valid From: 2017 Sep 07 2255 UTC Now Valid Until: 2017 Sep 09 0900 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: WARK04 Serial Number: 3311 Issue Time: 2017 Sep 08 2048 UTC EXTENDED WARNING: Geomagnetic K-index of 4 expected Extension to Serial Number: 3310 Valid From: 2017 Sep 06 2330 UTC Now Valid Until: 2017 Sep 09 2359 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 65 degrees Geomagnetic Latitude. Induced Currents –

Space Weather Message Code: ALTK06 Serial Number: 444 Issue Time: 2017 Sep 08 2018 UTC ALERT: Geomagnetic K-index of 6 Threshold Reached: 2017 Sep 08 2014 UTC Synoptic Period: 1800-2100 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: 1153 Issue Time: 2017 Sep 08 1821 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2017 Sep 08 1819 UTC Synoptic Period: 1800-2100 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.