Space Weather Message Code: WARK04 Serial Number: 4883 Issue Time: 2025 Mar 22 1121 UTC EXTENDED WARNING: Geomagnetic K-index of 4 expected Extension to Serial Number: 4882 Valid From: 2025 Mar 21 1715 UTC Now Valid Until: 2025 Mar 22 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 65 degrees Geomagnetic Latitude. Induced Currents –

Space Weather Message Code: WARK04 Serial Number: 4882 Issue Time: 2025 Mar 22 0603 UTC EXTENDED WARNING: Geomagnetic K-index of 4 expected Extension to Serial Number: 4881 Valid From: 2025 Mar 21 1715 UTC Now Valid Until: 2025 Mar 22 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: 1724 Issue Time: 2025 Mar 22 0337 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2025 Mar 22 0335 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: WATA50 Serial Number: 85 Issue Time: 2025 Mar 22 0313 UTC WATCH: Geomagnetic Storm Category G3 Predicted Highest Storm Level Predicted by Day: Mar 23: G3 (Strong) Mar 24: G1 (Minor) Mar 25: G2 (Moderate) 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 50 degrees Geomagnetic Latitude. Induced Currents

Space Weather Message Code: ALTK06 Serial Number: 619 Issue Time: 2025 Mar 22 0302 UTC ALERT: Geomagnetic K-index of 6 Threshold Reached: 2025 Mar 22 0259 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: 1723 Issue Time: 2025 Mar 22 0139 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2025 Mar 22 0136 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: ALTK05 Serial Number: 1722 Issue Time: 2025 Mar 21 2335 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2025 Mar 21 2330 UTC Synoptic Period: 2100-2400 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: 567 Issue Time: 2025 Mar 21 1943 UTC WARNING: Geomagnetic K-Index of 6 expected Valid From: 2025 Mar 21 1945 UTC Valid To: 2025 Mar 22 0600 UTC Warning Condition: Onset 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

Space Weather Message Code: ALTK05 Serial Number: 1721 Issue Time: 2025 Mar 21 1855 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2025 Mar 21 1855 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: 1996 Issue Time: 2025 Mar 21 1733 UTC WARNING: Geomagnetic K-index of 5 expected Valid From: 2025 Mar 21 1732 UTC Valid To: 2025 Mar 22 0900 UTC Warning Condition: Onset 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