Space Weather Message Code: WATA20 Serial Number: 797 Issue Time: 2017 Sep 15 2124 UTC WATCH: Geomagnetic Storm Category G1 Predicted Highest Storm Level Predicted by Day: Sep 16: G1 (Minor) Sep 17: None (Below G1) Sep 18: 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 60 degrees Geomagnetic Latitude.

Space Weather Message Code: ALTK05 Serial Number: 1161 Issue Time: 2017 Sep 15 1927 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2017 Sep 15 1926 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.

Space Weather Message Code: WARK05 Serial Number: 1403 Issue Time: 2017 Sep 15 1450 UTC EXTENDED WARNING: Geomagnetic K-index of 5 expected Extension to Serial Number: 1402 Valid From: 2017 Sep 14 1445 UTC Now Valid Until: 2017 Sep 15 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 60 degrees Geomagnetic Latitude. Induced Currents –

Space Weather Message Code: ALTK05 Serial Number: 1160 Issue Time: 2017 Sep 15 0901 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2017 Sep 15 0859 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: WARK05 Serial Number: 1402 Issue Time: 2017 Sep 15 0848 UTC EXTENDED WARNING: Geomagnetic K-index of 5 expected Extension to Serial Number: 1401 Valid From: 2017 Sep 14 1445 UTC Now Valid Until: 2017 Sep 15 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 60 degrees Geomagnetic Latitude. Induced Currents –

Space Weather Message Code: ALTK06 Serial Number: 446 Issue Time: 2017 Sep 15 0244 UTC ALERT: Geomagnetic K-index of 6 Threshold Reached: 2017 Sep 15 0240 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

Space Weather Message Code: ALTK05 Serial Number: 1159 Issue Time: 2017 Sep 15 0042 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2017 Sep 15 0036 UTC Synoptic Period: 0000-0300 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: 401 Issue Time: 2017 Sep 14 2057 UTC EXTENDED WARNING: Geomagnetic K-Index of 6 expected Extension to Serial Number: 400 Valid From: 2017 Sep 14 1555 UTC Now Valid Until: 2017 Sep 15 0300 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: ALTK05 Serial Number: 1158 Issue Time: 2017 Sep 14 2033 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2017 Sep 14 2032 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.

Space Weather Message Code: WARK05 Serial Number: 1400 Issue Time: 2017 Sep 14 2023 UTC EXTENDED WARNING: Geomagnetic K-index of 5 expected Extension to Serial Number: 1399 Valid From: 2017 Sep 14 1445 UTC Now Valid Until: 2017 Sep 15 0300 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 60 degrees Geomagnetic Latitude. Induced Currents –