Space Weather Message Code: ALTK06 Serial Number: 552 Issue Time: 2024 Mar 24 1907 UTC ALERT: Geomagnetic K-index of 6 Threshold Reached: 2024 Mar 24 1903 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: 1564 Issue Time: 2024 Mar 24 1843 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2024 Mar 24 1840 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: ALTK08 Serial Number: 30 Issue Time: 2024 Mar 24 1629 UTC ALERT: Geomagnetic K-index of 8, 9- Threshold Reached: 2024 Mar 24 1628 UTC Synoptic Period: 1500-1800 UTC Active Warning: Yes NOAA Scale: G4 – Severe NOAA Space Weather Scale descriptions can be found at www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 45 degrees Geomagnetic Latitude. Induced Currents – Possible widespread voltage control problems

Space Weather Message Code: ALTK07 Serial Number: 139 Issue Time: 2024 Mar 24 1547 UTC ALERT: Geomagnetic K-index of 7 Threshold Reached: 2024 Mar 24 1546 UTC Synoptic Period: 1500-1800 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: 99 Issue Time: 2024 Mar 24 1543 UTC WARNING: Geomagnetic K-index of 7 or greater expected Valid From: 2024 Mar 24 1543 UTC Valid To: 2024 Mar 25 0600 UTC Warning Condition: Onset NOAA Scale: G3 or greater 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 –

Space Weather Message Code: ALTK06 Serial Number: 551 Issue Time: 2024 Mar 24 1531 UTC ALERT: Geomagnetic K-index of 6 Threshold Reached: 2024 Mar 24 1526 UTC Synoptic Period: 1500-1800 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: 1563 Issue Time: 2024 Mar 24 1517 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2024 Mar 24 1516 UTC Synoptic Period: 1500-1800 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: 550 Issue Time: 2024 Mar 24 1445 UTC ALERT: Geomagnetic K-index of 6 Threshold Reached: 2024 Mar 24 1444 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: 1562 Issue Time: 2024 Mar 24 1443 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2024 Mar 24 1443 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: WARK04 Serial Number: 4571 Issue Time: 2024 Mar 24 1434 UTC EXTENDED WARNING: Geomagnetic K-index of 4 expected Extension to Serial Number: 4570 Valid From: 2024 Mar 23 0415 UTC Now Valid Until: 2024 Mar 25 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 –