Alerts Issued in May 2018


Space Weather Message Code: ALTK04
Serial Number: 2056
Issue Time: 2018 May 31 1735 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2018 May 31 1735 UTC
Synoptic Period: 1500-1800 UTC
Active Warning: Yes
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 visible at high latitudes such as Canada and Alaska.


Space Weather Message Code: WARK04
Serial Number: 3484
Issue Time: 2018 May 31 1722 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2018 May 31 1720 UTC
Valid To: 2018 Jun 01 0900 UTC
Warning Condition: Onset
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 visible at high latitudes such as Canada and Alaska.


Space Weather Message Code: WATA20
Serial Number: 830
Issue Time: 2018 May 30 1834 UTC

WATCH: Geomagnetic Storm Category G1 Predicted
Highest Storm Level Predicted by Day:
May 31: None (Below G1) Jun 01: G1 (Minor) Jun 02: G1 (Minor)
THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT
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.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.


Space Weather Message Code: WATA20
Serial Number: 829
Issue Time: 2018 May 29 1850 UTC

WATCH: Geomagnetic Storm Category G1 Predicted
Highest Storm Level Predicted by Day:
May 30: None (Below G1) May 31: None (Below G1) Jun 01: G1 (Minor)
THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT
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.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.


Space Weather Message Code: WARK04
Serial Number: 3483
Issue Time: 2018 May 23 0740 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2018 May 23 0740 UTC
Valid To: 2018 May 23 1100 UTC
Warning Condition: Onset
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 visible at high latitudes such as Canada and Alaska.


Space Weather Message Code: ALTEF3
Serial Number: 2789
Issue Time: 2018 May 17 1315 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2788
Begin Time: 2018 May 06 1400 UTC
Yesterday Maximum 2MeV Flux: 15763 pfu
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.


Space Weather Message Code: ALTEF3
Serial Number: 2788
Issue Time: 2018 May 16 0859 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2787
Begin Time: 2018 May 06 1400 UTC
Yesterday Maximum 2MeV Flux: 21333 pfu
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.


Space Weather Message Code: ALTEF3
Serial Number: 2787
Issue Time: 2018 May 15 0859 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2786
Begin Time: 2018 May 06 1400 UTC
Yesterday Maximum 2MeV Flux: 16682 pfu
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.


Space Weather Message Code: WATA20
Serial Number: 828
Issue Time: 2018 May 14 1928 UTC

WATCH: Geomagnetic Storm Category G1 Predicted
Highest Storm Level Predicted by Day:
May 15: None (Below G1) May 16: None (Below G1) May 17: G1 (Minor)
THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT
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.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.


Space Weather Message Code: ALTEF3
Serial Number: 2786
Issue Time: 2018 May 14 0900 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2785
Begin Time: 2018 May 06 1400 UTC
Yesterday Maximum 2MeV Flux: 12060 pfu
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.


Space Weather Message Code: ALTEF3
Serial Number: 2785
Issue Time: 2018 May 13 0941 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2784
Begin Time: 2018 May 06 1400 UTC
Yesterday Maximum 2MeV Flux: 14571 pfu
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.


Space Weather Message Code: ALTEF3
Serial Number: 2784
Issue Time: 2018 May 12 0859 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2783
Begin Time: 2018 May 06 1400 UTC
Yesterday Maximum 2MeV Flux: 52720 pfu
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.


Space Weather Message Code: WARK04
Serial Number: 3482
Issue Time: 2018 May 11 2316 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3481
Valid From: 2018 May 11 1932 UTC
Now Valid Until: 2018 May 12 0900 UTC
Warning Condition: Persistence
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 visible at high latitudes such as Canada and Alaska.


Space Weather Message Code: ALTK04
Serial Number: 2055
Issue Time: 2018 May 11 2101 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2018 May 11 2059 UTC
Synoptic Period: 2100-2400 UTC
Active Warning: Yes
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 visible at high latitudes such as Canada and Alaska.


Space Weather Message Code: WARK04
Serial Number: 3481
Issue Time: 2018 May 11 1931 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2018 May 11 1932 UTC
Valid To: 2018 May 11 2359 UTC
Warning Condition: Onset
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 visible at high latitudes such as Canada and Alaska.


Space Weather Message Code: ALTEF3
Serial Number: 2783
Issue Time: 2018 May 11 0859 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2782
Begin Time: 2018 May 06 1400 UTC
Yesterday Maximum 2MeV Flux: 74279 pfu
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.


Space Weather Message Code: ALTK04
Serial Number: 2054
Issue Time: 2018 May 11 0603 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2018 May 11 0559 UTC
Synoptic Period: 0300-0600 UTC
Active Warning: Yes
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 visible at high latitudes such as Canada and Alaska.


Space Weather Message Code: WARK04
Serial Number: 3480
Issue Time: 2018 May 11 0527 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2018 May 11 0525 UTC
Valid To: 2018 May 11 1500 UTC
Warning Condition: Onset
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 visible at high latitudes such as Canada and Alaska.


Space Weather Message Code: WARK04
Serial Number: 3479
Issue Time: 2018 May 10 1757 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3478
Valid From: 2018 May 09 1942 UTC
Now Valid Until: 2018 May 10 2359 UTC
Warning Condition: Persistence
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 visible at high latitudes such as Canada and Alaska.


Space Weather Message Code: ALTEF3
Serial Number: 2782
Issue Time: 2018 May 10 0900 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2781
Begin Time: 2018 May 06 1400 UTC
Yesterday Maximum 2MeV Flux: 56756 pfu
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.


Space Weather Message Code: WARK04
Serial Number: 3478
Issue Time: 2018 May 10 0855 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3477
Valid From: 2018 May 09 1942 UTC
Now Valid Until: 2018 May 10 1800 UTC
Warning Condition: Persistence
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 visible at high latitudes such as Canada and Alaska.


Space Weather Message Code: WARK04
Serial Number: 3477
Issue Time: 2018 May 09 2341 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3476
Valid From: 2018 May 09 1942 UTC
Now Valid Until: 2018 May 10 0900 UTC
Warning Condition: Persistence
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 visible at high latitudes such as Canada and Alaska.


Space Weather Message Code: ALTK04
Serial Number: 2053
Issue Time: 2018 May 09 2023 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2018 May 09 2022 UTC
Synoptic Period: 1800-2100 UTC
Active Warning: Yes
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 visible at high latitudes such as Canada and Alaska.


Space Weather Message Code: WARK04
Serial Number: 3476
Issue Time: 2018 May 09 1942 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2018 May 09 1942 UTC
Valid To: 2018 May 09 2359 UTC
Warning Condition: Onset
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 visible at high latitudes such as Canada and Alaska.


Space Weather Message Code: ALTEF3
Serial Number: 2781
Issue Time: 2018 May 09 0900 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2780
Begin Time: 2018 May 06 1400 UTC
Yesterday Maximum 2MeV Flux: 22852 pfu
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.


Space Weather Message Code: WARK04
Serial Number: 3475
Issue Time: 2018 May 09 0256 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3474
Valid From: 2018 May 08 1535 UTC
Now Valid Until: 2018 May 09 1200 UTC
Warning Condition: Persistence
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 visible at high latitudes such as Canada and Alaska.


Space Weather Message Code: WARK04
Serial Number: 3474
Issue Time: 2018 May 08 2026 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3473
Valid From: 2018 May 08 1535 UTC
Now Valid Until: 2018 May 09 0300 UTC
Warning Condition: Persistence
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 visible at high latitudes such as Canada and Alaska.


Space Weather Message Code: ALTK04
Serial Number: 2052
Issue Time: 2018 May 08 1800 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2018 May 08 1759 UTC
Synoptic Period: 1500-1800 UTC
Active Warning: Yes
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 visible at high latitudes such as Canada and Alaska.


Space Weather Message Code: WARK04
Serial Number: 3473
Issue Time: 2018 May 08 1534 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2018 May 08 1535 UTC
Valid To: 2018 May 08 2100 UTC
Warning Condition: Onset
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 visible at high latitudes such as Canada and Alaska.


Space Weather Message Code: ALTEF3
Serial Number: 2780
Issue Time: 2018 May 08 0908 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2779
Begin Time: 2018 May 06 1400 UTC
Yesterday Maximum 2MeV Flux: 26784 pfu
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.


Space Weather Message Code: WARK04
Serial Number: 3472
Issue Time: 2018 May 08 0546 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2018 May 08 0546 UTC
Valid To: 2018 May 08 1200 UTC
Warning Condition: Onset
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 visible at high latitudes such as Canada and Alaska.


Space Weather Message Code: ALTEF3
Serial Number: 2779
Issue Time: 2018 May 07 0906 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2778
Begin Time: 2018 May 06 1400 UTC
Yesterday Maximum 2MeV Flux: 11530 pfu
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.


Space Weather Message Code: ALTK05
Serial Number: 1220
Issue Time: 2018 May 07 0001 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2018 May 06 2359 UTC
Synoptic Period: 2100-2400 UTC
Active Warning: Yes
NOAA Scale: G1 - Minor
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.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.


Space Weather Message Code: WARK05
Serial Number: 1473
Issue Time: 2018 May 06 2031 UTC

WARNING: Geomagnetic K-index of 5 expected
Valid From: 2018 May 06 2030 UTC
Valid To: 2018 May 07 0600 UTC
Warning Condition: Onset
NOAA Scale: G1 - Minor
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.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.


Space Weather Message Code: WARK04
Serial Number: 3471
Issue Time: 2018 May 06 2021 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3470
Valid From: 2018 May 05 1350 UTC
Now Valid Until: 2018 May 07 1200 UTC
Warning Condition: Persistence
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 visible at high latitudes such as Canada and Alaska.


Space Weather Message Code: ALTEF3
Serial Number: 2778
Issue Time: 2018 May 06 1416 UTC

ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Threshold Reached: 2018 May 06 1400 UTC
Station: GOES-15
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.


Space Weather Message Code: WARK04
Serial Number: 3470
Issue Time: 2018 May 06 0834 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3469
Valid From: 2018 May 05 1350 UTC
Now Valid Until: 2018 May 06 2100 UTC
Warning Condition: Persistence
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 visible at high latitudes such as Canada and Alaska.


Space Weather Message Code: ALTK06
Serial Number: 462
Issue Time: 2018 May 06 0218 UTC

ALERT: Geomagnetic K-index of 6
Threshold Reached: 2018 May 06 0218 UTC
Synoptic Period: 0000-0300 UTC
Active Warning: Yes
NOAA Scale: G2 - Moderate
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 power systems may experience voltage alarms.
Spacecraft - Satellite orientation irregularities may occur; increased drag on low Earth-orbit satellites is possible.
Radio - HF (high frequency) radio propagation can fade at higher latitudes.
Aurora - Aurora may be seen as low as New York to Wisconsin to Washington state.


Space Weather Message Code: WARK05
Serial Number: 1472
Issue Time: 2018 May 06 0121 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 1471
Valid From: 2018 May 05 1715 UTC
Now Valid Until: 2018 May 06 0900 UTC
Warning Condition: Onset
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.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.


Space Weather Message Code: WARK06
Serial Number: 417
Issue Time: 2018 May 06 0121 UTC

WARNING: Geomagnetic K-Index of 6 expected
Valid From: 2018 May 06 0117 UTC
Valid To: 2018 May 06 0600 UTC
Warning Condition: Onset
NOAA Scale: G2 - Moderate
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 power systems may experience voltage alarms.
Spacecraft - Satellite orientation irregularities may occur; increased drag on low Earth-orbit satellites is possible.
Radio - HF (high frequency) radio propagation can fade at higher latitudes.
Aurora - Aurora may be seen as low as New York to Wisconsin to Washington state.


Space Weather Message Code: ALTK05
Serial Number: 1219
Issue Time: 2018 May 06 0047 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2018 May 06 0047 UTC
Synoptic Period: 0000-0300 UTC
Active Warning: Yes
NOAA Scale: G1 - Minor
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.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.


Space Weather Message Code: ALTK05
Serial Number: 1218
Issue Time: 2018 May 05 2253 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2018 May 05 2252 UTC
Synoptic Period: 2100-2400 UTC
Active Warning: Yes
NOAA Scale: G1 - Minor
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.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.


Space Weather Message Code: ALTK05
Serial Number: 1217
Issue Time: 2018 May 05 1802 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2018 May 05 1759 UTC
Synoptic Period: 1500-1800 UTC
Active Warning: Yes
NOAA Scale: G1 - Minor
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.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.


Space Weather Message Code: WARK05
Serial Number: 1471
Issue Time: 2018 May 05 1716 UTC

WARNING: Geomagnetic K-index of 5 expected
Valid From: 2018 May 05 1715 UTC
Valid To: 2018 May 06 0300 UTC
Warning Condition: Onset
NOAA Scale: G1 - Minor
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.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.


Space Weather Message Code: WARK04
Serial Number: 3469
Issue Time: 2018 May 05 1716 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3468
Valid From: 2018 May 05 1350 UTC
Now Valid Until: 2018 May 06 0900 UTC
Warning Condition: Persistence
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 visible at high latitudes such as Canada and Alaska.


Space Weather Message Code: ALTK04
Serial Number: 2051
Issue Time: 2018 May 05 1552 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2018 May 05 1552 UTC
Synoptic Period: 1500-1800 UTC
Active Warning: Yes
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 visible at high latitudes such as Canada and Alaska.


Space Weather Message Code: WARK04
Serial Number: 3468
Issue Time: 2018 May 05 1351 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2018 May 05 1350 UTC
Valid To: 2018 May 05 1800 UTC
Warning Condition: Onset
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 visible at high latitudes such as Canada and Alaska.


Space Weather Message Code: WATA20
Serial Number: 827
Issue Time: 2018 May 04 1607 UTC

WATCH: Geomagnetic Storm Category G1 Predicted
Highest Storm Level Predicted by Day:
May 05: None (Below G1) May 06: G1 (Minor) May 07: G1 (Minor)
THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT
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.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.


Space Weather Message Code: WATA20
Serial Number: 826
Issue Time: 2018 May 03 1458 UTC

WATCH: Geomagnetic Storm Category G1 Predicted
Highest Storm Level Predicted by Day:
May 04: None (Below G1) May 05: None (Below G1) May 06: G1 (Minor)
THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT
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.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.