Space Weather Message Code: WARK04 Serial Number: 4971 Issue Time: 2025 May 20 0711 UTC WARNING: Geomagnetic K-index of 4 expected Valid From: 2025 May 20 0711 UTC Valid To: 2025 May 20 1500 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: WARK04 Serial Number: 4970 Issue Time: 2025 May 18 2354 UTC EXTENDED WARNING: Geomagnetic K-index of 4 expected Extension to Serial Number: 4969 Valid From: 2025 May 16 2255 UTC Now Valid Until: 2025 May 19 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: WARK04 Serial Number: 4969 Issue Time: 2025 May 18 1455 UTC EXTENDED WARNING: Geomagnetic K-index of 4 expected Extension to Serial Number: 4968 Valid From: 2025 May 16 2255 UTC Now Valid Until: 2025 May 18 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: ALTK05 Serial Number: 1773 Issue Time: 2025 May 18 0835 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2025 May 18 0834 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: 4968 Issue Time: 2025 May 17 2106 UTC EXTENDED WARNING: Geomagnetic K-index of 4 expected Extension to Serial Number: 4967 Valid From: 2025 May 16 2255 UTC Now Valid Until: 2025 May 18 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: WARK05 Serial Number: 2045 Issue Time: 2025 May 17 2055 UTC EXTENDED WARNING: Geomagnetic K-index of 5 expected Extension to Serial Number: 2044 Valid From: 2025 May 17 0050 UTC Now Valid Until: 2025 May 18 1200 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: WARK05 Serial Number: 2044 Issue Time: 2025 May 17 1152 UTC EXTENDED WARNING: Geomagnetic K-index of 5 expected Extension to Serial Number: 2043 Valid From: 2025 May 17 0050 UTC Now Valid Until: 2025 May 17 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: 1772 Issue Time: 2025 May 17 1125 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2025 May 17 1122 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: ALTK05 Serial Number: 1771 Issue Time: 2025 May 17 0507 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2025 May 17 0459 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: 629 Issue Time: 2025 May 17 0054 UTC ALERT: Geomagnetic K-index of 6 Threshold Reached: 2025 May 17 0054 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