Space Weather Message Code: ALTK06 Serial Number: 478 Issue Time: 2021 Mar 20 0803 UTC ALERT: Geomagnetic K-index of 6 Threshold Reached: 2021 Mar 20 0800 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: 1317 Issue Time: 2021 Mar 20 1104 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2021 Mar 20 1104 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: 478 Issue Time: 2021 Mar 20 0803 UTC ALERT: Geomagnetic K-index of 6 Threshold Reached: 2021 Mar 20 0800 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: WARK06 Serial Number: 440 Issue Time: 2021 Mar 20 0721 UTC WARNING: Geomagnetic K-Index of 6 expected Valid From: 2021 Mar 20 0720 UTC Valid To: 2021 Mar 20 1200 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: 1316 Issue Time: 2021 Mar 20 0712 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2021 Mar 20 0710 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: WARK05 Serial Number: 1586 Issue Time: 2021 Mar 20 0647 UTC WARNING: Geomagnetic K-index of 5 expected Valid From: 2021 Mar 20 0645 UTC Valid To: 2021 Mar 20 1500 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

Space Weather Message Code: ALTK04 Serial Number: 2203 Issue Time: 2021 Mar 20 0646 UTC ALERT: Geomagnetic K-index of 4 Threshold Reached: 2021 Mar 20 0645 UTC Synoptic Period: 0600-0900 UTC Active Warning: Yes 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 – Aurora may be

Space Weather Message Code: WARK04 Serial Number: 3861 Issue Time: 2021 Mar 20 0250 UTC WARNING: Geomagnetic K-index of 4 expected Valid From: 2021 Mar 20 0250 UTC Valid To: 2021 Mar 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: WATA20 Serial Number: 890 Issue Time: 2021 Mar 19 1706 UTC WATCH: Geomagnetic Storm Category G1 Predicted Highest Storm Level Predicted by Day: Mar 20: G1 (Minor) Mar 21: G1 (Minor) Mar 22: G1 (Minor) THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT Comment: G1 (Minor) Watch issued for likely high speed stream effects originating from a large, negative polarity coronal hole. NOAA Space Weather Scale descriptions

Space Weather Message Code: WATA20 Serial Number: 889 Issue Time: 2021 Mar 18 1917 UTC WATCH: Geomagnetic Storm Category G1 Predicted Highest Storm Level Predicted by Day: Mar 19: None (Below G1) Mar 20: G1 (Minor) Mar 21: G1 (Minor) 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 60 degrees Geomagnetic Latitude. Induced