Space Weather Message Code: WARK04 Serial Number: 3218 Issue Time: 2017 May 18 0119 UTC WARNING: Geomagnetic K-index of 4 expected Valid From: 2017 May 18 0115 UTC Valid To: 2017 May 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

Space Weather Message Code: WATA30 Serial Number: 160 Issue Time: 2017 May 17 1752 UTC WATCH: Geomagnetic Storm Category G2 Predicted Highest Storm Level Predicted by Day: May 18: G1 (Minor) May 19: G2 (Moderate) May 20: 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 55 degrees Geomagnetic Latitude. Induced Currents

Space Weather Message Code: WATA30 Serial Number: 159 Issue Time: 2017 May 17 1748 UTC CANCEL WATCH: Geomagnetic Storm Category G2 Predicted Cancel Serial Number: 158 Original Issue Time: 2017 May 16 2126 UTC Comment: The G2 (Moderate) Geomagnetic Storm Watch for 17 May 2017 has been canceled. A new Watch product will be issued shortly to update conditions expected 18-20 May 2017 NOAA Space Weather Scale descriptions can be

Space Weather Message Code: WATA30 Serial Number: 158 Issue Time: 2017 May 16 2126 UTC WATCH: Geomagnetic Storm Category G2 Predicted Highest Storm Level Predicted by Day: May 17: G2 (Moderate) May 18: G2 (Moderate) May 19: 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 55 degrees Geomagnetic Latitude. Induced Currents

Space Weather Message Code: WARK04 Serial Number: 3217 Issue Time: 2017 May 15 2208 UTC EXTENDED WARNING: Geomagnetic K-index of 4 expected Extension to Serial Number: 3216 Valid From: 2017 May 15 0957 UTC Now Valid Until: 2017 May 16 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: WATA30 Serial Number: 157 Issue Time: 2017 May 15 2106 UTC WATCH: Geomagnetic Storm Category G2 Predicted Highest Storm Level Predicted by Day: May 16: G1 (Minor) May 17: G2 (Moderate) May 18: 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 55 degrees Geomagnetic Latitude. Induced Currents

Space Weather Message Code: ALTK04 Serial Number: 1976 Issue Time: 2017 May 15 1152 UTC ALERT: Geomagnetic K-index of 4 Threshold Reached: 2017 May 15 1150 UTC Synoptic Period: 0900-1200 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: 3216 Issue Time: 2017 May 15 0958 UTC WARNING: Geomagnetic K-index of 4 expected Valid From: 2017 May 15 0957 UTC Valid To: 2017 May 15 2359 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: WATA30 Serial Number: 156 Issue Time: 2017 May 14 2027 UTC WATCH: Geomagnetic Storm Category G2 Predicted Highest Storm Level Predicted by Day: May 15: None (Below G1) May 16: G1 (Minor) May 17: 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 55 degrees Geomagnetic Latitude. Induced

Space Weather Message Code: WATA20 Serial Number: 785 Issue Time: 2017 May 13 1929 UTC WATCH: Geomagnetic Storm Category G1 Predicted Highest Storm Level Predicted by Day: May 14: None (Below G1) May 15: None (Below G1) May 16: 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.