Alerts Issued in August 2018


Space Weather Message Code: ALTEF3
Serial Number: 2833
Issue Time: 2018 Aug 31 0859 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2832
Begin Time: 2018 Aug 18 1410 UTC
Yesterday Maximum 2MeV Flux: 61001 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: 2832
Issue Time: 2018 Aug 30 0900 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2831
Begin Time: 2018 Aug 18 1410 UTC
Yesterday Maximum 2MeV Flux: 57922 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: 2831
Issue Time: 2018 Aug 29 0859 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2830
Begin Time: 2018 Aug 18 1410 UTC
Yesterday Maximum 2MeV Flux: 97635 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: 2830
Issue Time: 2018 Aug 28 0901 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2829
Begin Time: 2018 Aug 18 1410 UTC
Yesterday Maximum 2MeV Flux: 39767 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: 3524
Issue Time: 2018 Aug 28 0203 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3523
Valid From: 2018 Aug 25 2109 UTC
Now Valid Until: 2018 Aug 28 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: WARK05
Serial Number: 1490
Issue Time: 2018 Aug 27 1914 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 1489
Valid From: 2018 Aug 27 1632 UTC
Now Valid Until: 2018 Aug 27 2359 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: ALTK05
Serial Number: 1234
Issue Time: 2018 Aug 27 1912 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2018 Aug 27 1912 UTC
Synoptic Period: 1800-2100 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: WARK04
Serial Number: 3523
Issue Time: 2018 Aug 27 1837 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3522
Valid From: 2018 Aug 25 2109 UTC
Now Valid Until: 2018 Aug 28 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: ALTK06
Serial Number: 467
Issue Time: 2018 Aug 27 1759 UTC

ALERT: Geomagnetic K-index of 6
Threshold Reached: 2018 Aug 27 1759 UTC
Synoptic Period: 1500-1800 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: WARK06
Serial Number: 422
Issue Time: 2018 Aug 27 1749 UTC

WARNING: Geomagnetic K-Index of 6 expected
Valid From: 2018 Aug 27 1748 UTC
Valid To: 2018 Aug 27 2000 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: 1233
Issue Time: 2018 Aug 27 1739 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2018 Aug 27 1739 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: 1489
Issue Time: 2018 Aug 27 1633 UTC

WARNING: Geomagnetic K-index of 5 expected
Valid From: 2018 Aug 27 1632 UTC
Valid To: 2018 Aug 27 2000 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: 3522
Issue Time: 2018 Aug 27 1359 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3521
Valid From: 2018 Aug 25 2109 UTC
Now Valid Until: 2018 Aug 27 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: ALTEF3
Serial Number: 2829
Issue Time: 2018 Aug 27 0902 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2828
Begin Time: 2018 Aug 18 1410 UTC
Yesterday Maximum 2MeV Flux: 6146 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: 3521
Issue Time: 2018 Aug 27 0856 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3520
Valid From: 2018 Aug 25 2109 UTC
Now Valid Until: 2018 Aug 27 1500 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: 3520
Issue Time: 2018 Aug 26 2349 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3519
Valid From: 2018 Aug 25 2109 UTC
Now Valid Until: 2018 Aug 27 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: WARK05
Serial Number: 1488
Issue Time: 2018 Aug 26 2339 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 1487
Valid From: 2018 Aug 25 2146 UTC
Now Valid Until: 2018 Aug 27 0900 UTC
Warning Condition: Persistence
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: 421
Issue Time: 2018 Aug 26 2036 UTC

WARNING: Geomagnetic K-Index of 6 expected
Valid From: 2018 Aug 26 2035 UTC
Valid To: 2018 Aug 26 2359 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: 1232
Issue Time: 2018 Aug 26 2023 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2018 Aug 26 2020 UTC
Synoptic Period: 1800-2100 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: ALTK06
Serial Number: 466
Issue Time: 2018 Aug 26 1625 UTC

ALERT: Geomagnetic K-index of 6
Threshold Reached: 2018 Aug 26 1623 UTC
Synoptic Period: 1500-1800 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: 1487
Issue Time: 2018 Aug 26 1614 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 1486
Valid From: 2018 Aug 25 2146 UTC
Now Valid Until: 2018 Aug 26 2359 UTC
Warning Condition: Persistence
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: 420
Issue Time: 2018 Aug 26 1614 UTC

WARNING: Geomagnetic K-Index of 6 expected
Valid From: 2018 Aug 26 1613 UTC
Valid To: 2018 Aug 26 1800 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: 1231
Issue Time: 2018 Aug 26 1602 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2018 Aug 26 1602 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: ALTEF3
Serial Number: 2828
Issue Time: 2018 Aug 26 1541 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2827
Begin Time: 2018 Aug 18 1410 UTC
Yesterday Maximum 2MeV Flux: 1929 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: 1230
Issue Time: 2018 Aug 26 1421 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2018 Aug 26 1418 UTC
Synoptic Period: 1200-1500 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: 1229
Issue Time: 2018 Aug 26 1134 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2018 Aug 26 1134 UTC
Synoptic Period: 0900-1200 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: 1486
Issue Time: 2018 Aug 26 1133 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 1485
Valid From: 2018 Aug 25 2146 UTC
Now Valid Until: 2018 Aug 26 1800 UTC
Warning Condition: Persistence
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: 3519
Issue Time: 2018 Aug 26 1133 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3518
Valid From: 2018 Aug 25 2109 UTC
Now Valid Until: 2018 Aug 26 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: ALTK07
Serial Number: 113
Issue Time: 2018 Aug 26 0739 UTC

ALERT: Geomagnetic K-index of 7
Threshold Reached: 2018 Aug 26 0738 UTC
Synoptic Period: 0600-0900 UTC
Active Warning: Yes
NOAA Scale: G3 - Strong
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Area of impact primarily poleward of 50 degrees Geomagnetic Latitude.
Induced Currents - Power system voltage irregularities possible, false alarms may be triggered on some protection devices.
Spacecraft - Systems may experience surface charging; increased drag on low Earth-orbit satellites and orientation problems may occur.
Navigation - Intermittent satellite navigation (GPS) problems, including loss-of-lock and increased range error may occur.
Radio - HF (high frequency) radio may be intermittent.
Aurora - Aurora may be seen as low as Pennsylvania to Iowa to Oregon.


Space Weather Message Code: WARK07
Serial Number: 75
Issue Time: 2018 Aug 26 0739 UTC

EXTENDED WARNING: Geomagnetic K-index of 7 or greater expected
Extension to Serial Number: 74
Valid From: 2018 Aug 26 0444 UTC
Now Valid Until: 2018 Aug 26 1200 UTC
Warning Condition: Persistence
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Area of impact primarily poleward of 50 degrees Geomagnetic Latitude.
Induced Currents - Power system voltage irregularities possible, false alarms may be triggered on some protection devices.
Spacecraft - Systems may experience surface charging; increased drag on low Earth-orbit satellites and orientation problems may occur.
Navigation - Intermittent satellite navigation (GPS) problems, including loss-of-lock and increased range error may occur.
Radio - HF (high frequency) radio may be intermittent.
Aurora - Aurora may be seen as low as Pennsylvania to Iowa to Oregon.


Space Weather Message Code: WARK06
Serial Number: 419
Issue Time: 2018 Aug 26 0707 UTC

EXTENDED WARNING: Geomagnetic K-Index of 6 expected
Extension to Serial Number: 418
Valid From: 2018 Aug 26 0241 UTC
Now Valid Until: 2018 Aug 26 1200 UTC
Warning Condition: Persistence
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: ALTK06
Serial Number: 465
Issue Time: 2018 Aug 26 0706 UTC

ALERT: Geomagnetic K-index of 6
Threshold Reached: 2018 Aug 26 0706 UTC
Synoptic Period: 0600-0900 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: ALTK05
Serial Number: 1228
Issue Time: 2018 Aug 26 0638 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2018 Aug 26 0637 UTC
Synoptic Period: 0600-0900 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: ALTK07
Serial Number: 112
Issue Time: 2018 Aug 26 0601 UTC

ALERT: Geomagnetic K-index of 7
Threshold Reached: 2018 Aug 26 0559 UTC
Synoptic Period: 0300-0600 UTC
Active Warning: Yes
NOAA Scale: G3 - Strong
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Area of impact primarily poleward of 50 degrees Geomagnetic Latitude.
Induced Currents - Power system voltage irregularities possible, false alarms may be triggered on some protection devices.
Spacecraft - Systems may experience surface charging; increased drag on low Earth-orbit satellites and orientation problems may occur.
Navigation - Intermittent satellite navigation (GPS) problems, including loss-of-lock and increased range error may occur.
Radio - HF (high frequency) radio may be intermittent.
Aurora - Aurora may be seen as low as Pennsylvania to Iowa to Oregon.


Space Weather Message Code: WARK07
Serial Number: 74
Issue Time: 2018 Aug 26 0444 UTC

WARNING: Geomagnetic K-index of 7 or greater expected
Valid From: 2018 Aug 26 0444 UTC
Valid To: 2018 Aug 26 0900 UTC
Warning Condition: Onset
NOAA Scale: G3 or greater - Strong to Extreme
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Area of impact primarily poleward of 50 degrees Geomagnetic Latitude.
Induced Currents - Power system voltage irregularities possible, false alarms may be triggered on some protection devices.
Spacecraft - Systems may experience surface charging; increased drag on low Earth-orbit satellites and orientation problems may occur.
Navigation - Intermittent satellite navigation (GPS) problems, including loss-of-lock and increased range error may occur.
Radio - HF (high frequency) radio may be intermittent.
Aurora - Aurora may be seen as low as Pennsylvania to Iowa to Oregon.


Space Weather Message Code: ALTK06
Serial Number: 464
Issue Time: 2018 Aug 26 0425 UTC

ALERT: Geomagnetic K-index of 6
Threshold Reached: 2018 Aug 26 0425 UTC
Synoptic Period: 0300-0600 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: ALTK05
Serial Number: 1227
Issue Time: 2018 Aug 26 0346 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2018 Aug 26 0346 UTC
Synoptic Period: 0300-0600 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: ALTK06
Serial Number: 463
Issue Time: 2018 Aug 26 0257 UTC

ALERT: Geomagnetic K-index of 6
Threshold Reached: 2018 Aug 26 0257 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: WARK06
Serial Number: 418
Issue Time: 2018 Aug 26 0241 UTC

WARNING: Geomagnetic K-Index of 6 expected
Valid From: 2018 Aug 26 0241 UTC
Valid To: 2018 Aug 26 0900 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: WARK05
Serial Number: 1485
Issue Time: 2018 Aug 26 0241 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 1484
Valid From: 2018 Aug 25 2146 UTC
Now Valid Until: 2018 Aug 26 1200 UTC
Warning Condition: Persistence
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: 3518
Issue Time: 2018 Aug 26 0213 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3517
Valid From: 2018 Aug 25 2109 UTC
Now Valid Until: 2018 Aug 26 1500 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: ALTK05
Serial Number: 1226
Issue Time: 2018 Aug 26 0154 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2018 Aug 26 0154 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: WARK05
Serial Number: 1484
Issue Time: 2018 Aug 25 2146 UTC

WARNING: Geomagnetic K-index of 5 expected
Valid From: 2018 Aug 25 2146 UTC
Valid To: 2018 Aug 26 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: ALTK04
Serial Number: 2072
Issue Time: 2018 Aug 25 2143 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2018 Aug 25 2143 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: 3517
Issue Time: 2018 Aug 25 2109 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2018 Aug 25 2109 UTC
Valid To: 2018 Aug 26 0600 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: 2827
Issue Time: 2018 Aug 25 1716 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2826
Begin Time: 2018 Aug 18 1410 UTC
Yesterday Maximum 2MeV Flux: 1967 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: 2826
Issue Time: 2018 Aug 24 1231 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2825
Begin Time: 2018 Aug 18 1410 UTC
Yesterday Maximum 2MeV Flux: 4038 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: 2825
Issue Time: 2018 Aug 23 1035 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2824
Begin Time: 2018 Aug 18 1410 UTC
Yesterday Maximum 2MeV Flux: 4095 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: 2824
Issue Time: 2018 Aug 22 0956 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2823
Begin Time: 2018 Aug 18 1410 UTC
Yesterday Maximum 2MeV Flux: 10333 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: 2823
Issue Time: 2018 Aug 21 0636 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2822
Begin Time: 2018 Aug 18 1410 UTC
Yesterday Maximum 2MeV Flux: 4163 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: 2071
Issue Time: 2018 Aug 20 1923 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2018 Aug 20 1923 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: 3516
Issue Time: 2018 Aug 20 1920 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2018 Aug 20 1919 UTC
Valid To: 2018 Aug 21 0000 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: 2822
Issue Time: 2018 Aug 20 1916 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2821
Begin Time: 2018 Aug 18 1410 UTC
Yesterday Maximum 2MeV Flux: 18287 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: 2070
Issue Time: 2018 Aug 20 0300 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2018 Aug 20 0259 UTC
Synoptic Period: 0000-0300 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: 3515
Issue Time: 2018 Aug 20 0036 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2018 Aug 20 0036 UTC
Valid To: 2018 Aug 20 1400 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: 2821
Issue Time: 2018 Aug 19 0859 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2820
Begin Time: 2018 Aug 18 1410 UTC
Yesterday Maximum 2MeV Flux: 7218 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: 2820
Issue Time: 2018 Aug 18 1426 UTC

ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Threshold Reached: 2018 Aug 18 1410 UTC
Station: GOES15
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: 2069
Issue Time: 2018 Aug 18 0809 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2018 Aug 18 0808 UTC
Synoptic Period: 0600-0900 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: 3514
Issue Time: 2018 Aug 18 0559 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2018 Aug 18 0600 UTC
Valid To: 2018 Aug 18 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: ALTK04
Serial Number: 2068
Issue Time: 2018 Aug 17 0413 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2018 Aug 17 0412 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: 3513
Issue Time: 2018 Aug 17 0345 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2018 Aug 17 0345 UTC
Valid To: 2018 Aug 17 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: WARK04
Serial Number: 3512
Issue Time: 2018 Aug 16 0203 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3511
Valid From: 2018 Aug 15 2215 UTC
Now Valid Until: 2018 Aug 16 1000 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: 2067
Issue Time: 2018 Aug 16 0002 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2018 Aug 15 2359 UTC
Synoptic Period: 2100-2359 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: 3511
Issue Time: 2018 Aug 15 2212 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2018 Aug 15 2215 UTC
Valid To: 2018 Aug 16 0300 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: ALTK04
Serial Number: 2066
Issue Time: 2018 Aug 15 1355 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2018 Aug 15 1350 UTC
Synoptic Period: 1200-1500 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: 3510
Issue Time: 2018 Aug 15 1142 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2018 Aug 15 1142 UTC
Valid To: 2018 Aug 15 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: ALTK04
Serial Number: 2065
Issue Time: 2018 Aug 12 0000 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2018 Aug 11 2359 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: 3509
Issue Time: 2018 Aug 11 1436 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2018 Aug 11 1436 UTC
Valid To: 2018 Aug 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.