Space Weather Message Code: ALTK07 Serial Number: 122 Issue Time: 2023 Feb 27 1436 UTC ALERT: Geomagnetic K-index of 7 Threshold Reached: 2023 Feb 27 1435 UTC Synoptic Period: 1200-1500 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: 85 Issue Time: 2023 Feb 27 1354 UTC WARNING: Geomagnetic K-index of 7 or greater expected Valid From: 2023 Feb 27 1353 UTC Valid To: 2023 Feb 27 1800 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: 506 Issue Time: 2023 Feb 27 1301 UTC ALERT: Geomagnetic K-index of 6 Threshold Reached: 2023 Feb 27 1258 UTC Synoptic Period: 1200-1500 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: 1435 Issue Time: 2023 Feb 27 1233 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2023 Feb 27 1230 UTC Synoptic Period: 1200-1500 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: 121 Issue Time: 2023 Feb 27 1117 UTC ALERT: Geomagnetic K-index of 7 Threshold Reached: 2023 Feb 27 1115 UTC Synoptic Period: 0900-1200 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: 505 Issue Time: 2023 Feb 27 1053 UTC ALERT: Geomagnetic K-index of 6 Threshold Reached: 2023 Feb 27 1049 UTC Synoptic Period: 0900-1200 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: WARK04 Serial Number: 4295 Issue Time: 2023 Feb 27 1033 UTC EXTENDED WARNING: Geomagnetic K-index of 4 expected Extension to Serial Number: 4294 Valid From: 2023 Feb 25 2225 UTC Now Valid Until: 2023 Feb 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 65 degrees Geomagnetic Latitude. Induced Currents –

Space Weather Message Code: ALTK05 Serial Number: 1434 Issue Time: 2023 Feb 27 0942 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2023 Feb 27 0938 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: 471 Issue Time: 2023 Feb 27 0855 UTC EXTENDED WARNING: Geomagnetic K-Index of 6 expected Extension to Serial Number: 470 Valid From: 2023 Feb 26 2232 UTC Now Valid Until: 2023 Feb 28 0600 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: WARK07 Serial Number: 84 Issue Time: 2023 Feb 27 0819 UTC WARNING: Geomagnetic K-index of 7 or greater expected Valid From: 2023 Feb 27 0750 UTC Valid To: 2023 Feb 27 1200 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