Space Weather Message Code: WARK05 Serial Number: 1356 Issue Time: 2017 May 28 1443 UTC EXTENDED WARNING: Geomagnetic K-index of 5 expected Extension to Serial Number: 1355 Valid From: 2017 May 27 2204 UTC Now Valid Until: 2017 May 28 2100 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: 1115 Issue Time: 2017 May 28 1026 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2017 May 28 1020 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: ALTK06 Serial Number: 435 Issue Time: 2017 May 28 0824 UTC ALERT: Geomagnetic K-index of 6 Threshold Reached: 2017 May 28 0823 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: 1114 Issue Time: 2017 May 28 0719 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2017 May 28 0718 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: WARK04 Serial Number: 3225 Issue Time: 2017 May 28 0430 UTC EXTENDED WARNING: Geomagnetic K-index of 4 expected Extension to Serial Number: 3224 Valid From: 2017 May 27 1530 UTC Now Valid Until: 2017 May 29 0000 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: ALTK07 Serial Number: 105 Issue Time: 2017 May 28 0420 UTC ALERT: Geomagnetic K-index of 7 Threshold Reached: 2017 May 28 0419 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: WARK05 Serial Number: 1355 Issue Time: 2017 May 28 0410 UTC EXTENDED WARNING: Geomagnetic K-index of 5 expected Extension to Serial Number: 1354 Valid From: 2017 May 27 2204 UTC Now Valid Until: 2017 May 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 60 degrees Geomagnetic Latitude. Induced Currents –

Space Weather Message Code: ALTK06 Serial Number: 434 Issue Time: 2017 May 28 0350 UTC ALERT: Geomagnetic K-index of 6 Threshold Reached: 2017 May 28 0349 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: 1113 Issue Time: 2017 May 28 0330 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2017 May 28 0329 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: 433 Issue Time: 2017 May 28 0225 UTC ALERT: Geomagnetic K-index of 6 Threshold Reached: 2017 May 28 0224 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