Space Weather Message Code: WARK04 Serial Number: 3887 Issue Time: 2021 Apr 20 0431 UTC EXTENDED WARNING: Geomagnetic K-index of 4 expected Extension to Serial Number: 3886 Valid From: 2021 Apr 19 1924 UTC Now Valid Until: 2021 Apr 20 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 65 degrees Geomagnetic Latitude. Induced Currents –

Space Weather Message Code: ALTK04 Serial Number: 2214 Issue Time: 2021 Apr 19 2106 UTC ALERT: Geomagnetic K-index of 4 Threshold Reached: 2021 Apr 19 2059 UTC Synoptic Period: 1800-2100 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: 3886 Issue Time: 2021 Apr 19 1922 UTC WARNING: Geomagnetic K-index of 4 expected Valid From: 2021 Apr 19 1924 UTC Valid To: 2021 Apr 20 0600 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: WARK05 Serial Number: 1595 Issue Time: 2021 Apr 19 0516 UTC WARNING: Geomagnetic K-index of 5 expected Valid From: 2021 Apr 19 0516 UTC Valid To: 2021 Apr 19 1200 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: WARK04 Serial Number: 3885 Issue Time: 2021 Apr 19 0503 UTC EXTENDED WARNING: Geomagnetic K-index of 4 expected Extension to Serial Number: 3884 Valid From: 2021 Apr 18 2240 UTC Now Valid Until: 2021 Apr 19 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: ALTK04 Serial Number: 2213 Issue Time: 2021 Apr 19 0002 UTC ALERT: Geomagnetic K-index of 4 Threshold Reached: 2021 Apr 18 2359 UTC Synoptic Period: 2100-2400 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: 3884 Issue Time: 2021 Apr 18 2242 UTC WARNING: Geomagnetic K-index of 4 expected Valid From: 2021 Apr 18 2240 UTC Valid To: 2021 Apr 19 0600 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: 3883 Issue Time: 2021 Apr 18 0710 UTC EXTENDED WARNING: Geomagnetic K-index of 4 expected Extension to Serial Number: 3882 Valid From: 2021 Apr 17 2330 UTC Now Valid Until: 2021 Apr 18 1800 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: ALTK04 Serial Number: 2212 Issue Time: 2021 Apr 17 2344 UTC ALERT: Geomagnetic K-index of 4 Threshold Reached: 2021 Apr 17 2344 UTC Synoptic Period: 2100-2400 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: 3882 Issue Time: 2021 Apr 17 2333 UTC WARNING: Geomagnetic K-index of 4 expected Valid From: 2021 Apr 17 2330 UTC Valid To: 2021 Apr 18 0900 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