Alerts Issued in April 2017


Space Weather Message Code: ALTEF3
Serial Number: 2595
Issue Time: 2017 Apr 30 0740 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2594
Begin Time: 2017 Apr 21 1425 UTC
Yesterday Maximum 2MeV Flux: 15914 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: 2594
Issue Time: 2017 Apr 29 0500 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2593
Begin Time: 2017 Apr 21 1425 UTC
Yesterday Maximum 2MeV Flux: 56297 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: 2593
Issue Time: 2017 Apr 28 0500 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2592
Begin Time: 2017 Apr 21 1425 UTC
Yesterday Maximum 2MeV Flux: 54175 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: 2592
Issue Time: 2017 Apr 27 0500 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2591
Begin Time: 2017 Apr 21 1425 UTC
Yesterday Maximum 2MeV Flux: 66472 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: 784
Issue Time: 2017 Apr 26 1300 UTC

CANCEL WATCH: Geomagnetic Storm Category G1 Predicted
Cancel Serial Number: 783
Original Issue Time: 2017 Apr 23 1821 UTC

Comment: G1(Minor) storm conditions are no longer likely.
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: 2591
Issue Time: 2017 Apr 26 0500 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2590
Begin Time: 2017 Apr 21 1425 UTC
Yesterday Maximum 2MeV Flux: 52303 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: 2590
Issue Time: 2017 Apr 25 0500 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2589
Begin Time: 2017 Apr 21 1425 UTC
Yesterday Maximum 2MeV Flux: 54299 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: 3214
Issue Time: 2017 Apr 24 0848 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3213
Valid From: 2017 Apr 21 1546 UTC
Now Valid Until: 2017 Apr 25 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: 1351
Issue Time: 2017 Apr 24 0842 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 1350
Valid From: 2017 Apr 21 1920 UTC
Now Valid Until: 2017 Apr 24 1500 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: ALTEF3
Serial Number: 2589
Issue Time: 2017 Apr 24 0500 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2588
Begin Time: 2017 Apr 21 1425 UTC
Yesterday Maximum 2MeV Flux: 20545 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: WARK05
Serial Number: 1350
Issue Time: 2017 Apr 24 0256 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 1349
Valid From: 2017 Apr 21 1920 UTC
Now Valid Until: 2017 Apr 24 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: WATA20
Serial Number: 783
Issue Time: 2017 Apr 23 1821 UTC

WATCH: Geomagnetic Storm Category G1 Predicted
Highest Storm Level Predicted by Day:
Apr 24: G1 (Minor) Apr 25: G1 (Minor) Apr 26: 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: WARK05
Serial Number: 1349
Issue Time: 2017 Apr 23 1821 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 1348
Valid From: 2017 Apr 21 1920 UTC
Now Valid Until: 2017 Apr 24 0300 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: ALTK05
Serial Number: 1110
Issue Time: 2017 Apr 23 1802 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2017 Apr 23 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: ALTK05
Serial Number: 1109
Issue Time: 2017 Apr 23 1444 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2017 Apr 23 1442 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: 1108
Issue Time: 2017 Apr 23 1034 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2017 Apr 23 1034 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: ALTK06
Serial Number: 431
Issue Time: 2017 Apr 23 0852 UTC

ALERT: Geomagnetic K-index of 6
Threshold Reached: 2017 Apr 23 0852 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: WARK04
Serial Number: 3213
Issue Time: 2017 Apr 23 0852 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3212
Valid From: 2017 Apr 21 1546 UTC
Now Valid Until: 2017 Apr 24 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: WARK05
Serial Number: 1348
Issue Time: 2017 Apr 23 0852 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 1347
Valid From: 2017 Apr 21 1920 UTC
Now Valid Until: 2017 Apr 23 2100 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: 385
Issue Time: 2017 Apr 23 0852 UTC

EXTENDED WARNING: Geomagnetic K-Index of 6 expected
Extension to Serial Number: 384
Valid From: 2017 Apr 22 2255 UTC
Now Valid Until: 2017 Apr 23 1500 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: ALTK05
Serial Number: 1107
Issue Time: 2017 Apr 23 0754 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2017 Apr 23 0754 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: ALTEF3
Serial Number: 2588
Issue Time: 2017 Apr 23 0351 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2587
Begin Time: 2017 Apr 21 1425 UTC
Yesterday Maximum 2MeV Flux: 7467 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: ALTK06
Serial Number: 430
Issue Time: 2017 Apr 23 0001 UTC

ALERT: Geomagnetic K-index of 6
Threshold Reached: 2017 Apr 22 2359 UTC
Synoptic Period: 2100-2400 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: 384
Issue Time: 2017 Apr 22 2255 UTC

WARNING: Geomagnetic K-Index of 6 expected
Valid From: 2017 Apr 22 2255 UTC
Valid To: 2017 Apr 23 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: ALTK05
Serial Number: 1106
Issue Time: 2017 Apr 22 2240 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2017 Apr 22 2240 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: 1347
Issue Time: 2017 Apr 22 2046 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 1346
Valid From: 2017 Apr 21 1920 UTC
Now Valid Until: 2017 Apr 23 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: WATA30
Serial Number: 155
Issue Time: 2017 Apr 22 2046 UTC

WATCH: Geomagnetic Storm Category G2 Predicted
Highest Storm Level Predicted by Day:
Apr 23: G2 (Moderate) Apr 24: G1 (Minor) Apr 25: 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 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: 1105
Issue Time: 2017 Apr 22 1647 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2017 Apr 22 1641 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: ALTK06
Serial Number: 429
Issue Time: 2017 Apr 22 1426 UTC

ALERT: Geomagnetic K-index of 6
Threshold Reached: 2017 Apr 22 1425 UTC
Synoptic Period: 1200-1500 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: 383
Issue Time: 2017 Apr 22 1426 UTC

EXTENDED WARNING: Geomagnetic K-Index of 6 expected
Extension to Serial Number: 382
Valid From: 2017 Apr 22 0245 UTC
Now Valid Until: 2017 Apr 22 2100 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: ALTEF3
Serial Number: 2587
Issue Time: 2017 Apr 22 1356 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2586
Begin Time: 2017 Apr 21 1425 UTC
Yesterday Maximum 2MeV Flux: 2805 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: 1104
Issue Time: 2017 Apr 22 1348 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2017 Apr 22 1346 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: WARK05
Serial Number: 1346
Issue Time: 2017 Apr 22 1058 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 1345
Valid From: 2017 Apr 21 1920 UTC
Now Valid Until: 2017 Apr 22 2100 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: 382
Issue Time: 2017 Apr 22 1058 UTC

EXTENDED WARNING: Geomagnetic K-Index of 6 expected
Extension to Serial Number: 381
Valid From: 2017 Apr 22 0245 UTC
Now Valid Until: 2017 Apr 22 1500 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: ALTK05
Serial Number: 1103
Issue Time: 2017 Apr 22 1022 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2017 Apr 22 1022 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: ALTK05
Serial Number: 1102
Issue Time: 2017 Apr 22 0852 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2017 Apr 22 0852 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: WARK06
Serial Number: 381
Issue Time: 2017 Apr 22 0852 UTC

EXTENDED WARNING: Geomagnetic K-Index of 6 expected
Extension to Serial Number: 380
Valid From: 2017 Apr 22 0245 UTC
Now Valid Until: 2017 Apr 22 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: WARK04
Serial Number: 3212
Issue Time: 2017 Apr 22 0559 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3211
Valid From: 2017 Apr 21 1546 UTC
Now Valid Until: 2017 Apr 23 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: WARK05
Serial Number: 1345
Issue Time: 2017 Apr 22 0559 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 1344
Valid From: 2017 Apr 21 1920 UTC
Now Valid Until: 2017 Apr 22 1500 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: 380
Issue Time: 2017 Apr 22 0559 UTC

EXTENDED WARNING: Geomagnetic K-Index of 6 expected
Extension to Serial Number: 379
Valid From: 2017 Apr 22 0245 UTC
Now Valid Until: 2017 Apr 22 0900 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: 428
Issue Time: 2017 Apr 22 0559 UTC

ALERT: Geomagnetic K-index of 6
Threshold Reached: 2017 Apr 22 0559 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: 1101
Issue Time: 2017 Apr 22 0422 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2017 Apr 22 0421 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: WARK06
Serial Number: 379
Issue Time: 2017 Apr 22 0249 UTC

WARNING: Geomagnetic K-Index of 6 expected
Valid From: 2017 Apr 22 0245 UTC
Valid To: 2017 Apr 22 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: 1100
Issue Time: 2017 Apr 22 0238 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2017 Apr 22 0235 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: 1099
Issue Time: 2017 Apr 22 0001 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2017 Apr 21 2359 UTC
Synoptic Period: 2100-0000 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: 3211
Issue Time: 2017 Apr 21 2157 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3210
Valid From: 2017 Apr 21 1546 UTC
Now Valid Until: 2017 Apr 22 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: WARK05
Serial Number: 1344
Issue Time: 2017 Apr 21 2157 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 1343
Valid From: 2017 Apr 21 1920 UTC
Now Valid Until: 2017 Apr 22 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: ALTK05
Serial Number: 1098
Issue Time: 2017 Apr 21 2039 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2017 Apr 21 2032 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: WATA30
Serial Number: 154
Issue Time: 2017 Apr 21 1925 UTC

WATCH: Geomagnetic Storm Category G2 Predicted
Highest Storm Level Predicted by Day:
Apr 22: G1 (Minor) Apr 23: G2 (Moderate) Apr 24: 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 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: 1343
Issue Time: 2017 Apr 21 1924 UTC

WARNING: Geomagnetic K-index of 5 expected
Valid From: 2017 Apr 21 1920 UTC
Valid To: 2017 Apr 21 2359 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: 1974
Issue Time: 2017 Apr 21 1642 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2017 Apr 21 1638 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: 3210
Issue Time: 2017 Apr 21 1548 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2017 Apr 21 1546 UTC
Valid To: 2017 Apr 21 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: 2586
Issue Time: 2017 Apr 21 1447 UTC

ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Threshold Reached: 2017 Apr 21 1425 UTC
Station: GOES13
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: WATA30
Serial Number: 153
Issue Time: 2017 Apr 20 1959 UTC

WATCH: Geomagnetic Storm Category G2 Predicted
Highest Storm Level Predicted by Day:
Apr 21: None (Below G1) Apr 22: None (Below G1) Apr 23: G2 (Moderate)
THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT
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: WARK04
Serial Number: 3209
Issue Time: 2017 Apr 20 1755 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3208
Valid From: 2017 Apr 20 0105 UTC
Now Valid Until: 2017 Apr 20 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: ALTK05
Serial Number: 1097
Issue Time: 2017 Apr 20 1207 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2017 Apr 20 1159 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: WARK06
Serial Number: 378
Issue Time: 2017 Apr 20 1138 UTC

CANCEL WARNING: Geomagnetic K-Index of 6 expected
Cancel Serial Number: 377
Original Issue Time: 2017 Apr 20 0345 UTC

Comment: Conditions are no longer favorable for G2-Moderate storm levels
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: WARK04
Serial Number: 3208
Issue Time: 2017 Apr 20 1108 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3207
Valid From: 2017 Apr 20 0105 UTC
Now Valid Until: 2017 Apr 20 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: ALTK06
Serial Number: 427
Issue Time: 2017 Apr 20 0434 UTC

ALERT: Geomagnetic K-index of 6
Threshold Reached: 2017 Apr 20 0433 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: WARK05
Serial Number: 1342
Issue Time: 2017 Apr 20 0351 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 1341
Valid From: 2017 Apr 20 0138 UTC
Now Valid Until: 2017 Apr 20 1500 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: 377
Issue Time: 2017 Apr 20 0347 UTC

EXTENDED WARNING: Geomagnetic K-Index of 6 expected
Extension to Serial Number: 376
Valid From: 2017 Apr 20 0345 UTC
Now Valid Until: 2017 Apr 20 1500 UTC
Warning Condition: Onset
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: WARK04
Serial Number: 3207
Issue Time: 2017 Apr 20 0346 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3206
Valid From: 2017 Apr 20 0105 UTC
Now Valid Until: 2017 Apr 20 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: WARK06
Serial Number: 376
Issue Time: 2017 Apr 20 0345 UTC

WARNING: Geomagnetic K-Index of 6 expected
Valid From: 2017 Apr 20 0345 UTC
Valid To: 2017 Apr 20 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: ALTK05
Serial Number: 1096
Issue Time: 2017 Apr 20 0337 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2017 Apr 20 0336 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: ALTK05
Serial Number: 1095
Issue Time: 2017 Apr 20 0301 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2017 Apr 20 0259 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: 1341
Issue Time: 2017 Apr 20 0138 UTC

WARNING: Geomagnetic K-index of 5 expected
Valid From: 2017 Apr 20 0138 UTC
Valid To: 2017 Apr 20 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: 1973
Issue Time: 2017 Apr 20 0125 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2017 Apr 20 0125 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: 3206
Issue Time: 2017 Apr 20 0104 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2017 Apr 20 0105 UTC
Valid To: 2017 Apr 20 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: ALTK05
Serial Number: 1094
Issue Time: 2017 Apr 19 0601 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2017 Apr 19 0559 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: WARK05
Serial Number: 1340
Issue Time: 2017 Apr 19 0527 UTC

WARNING: Geomagnetic K-index of 5 expected
Valid From: 2017 Apr 19 0526 UTC
Valid To: 2017 Apr 19 1200 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: 1972
Issue Time: 2017 Apr 19 0449 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2017 Apr 19 0449 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: 3205
Issue Time: 2017 Apr 19 0056 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2017 Apr 19 0100 UTC
Valid To: 2017 Apr 19 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: ALTTP2
Serial Number: 1052
Issue Time: 2017 Apr 18 2109 UTC

ALERT: Type II Radio Emission
Begin Time: 2017 Apr 18 1949 UTC
Estimated Velocity: 631 km/s
www.swpc.noaa.gov/noaa-scales-explanation
Description: Type II emissions occur in association with eruptions on the sun and typically indicate a coronal mass ejection is associated with a flare event.


Space Weather Message Code: ALTTP4
Serial Number: 535
Issue Time: 2017 Apr 18 2109 UTC

ALERT: Type IV Radio Emission
Begin Time: 2017 Apr 18 1953 UTC
www.swpc.noaa.gov/noaa-scales-explanation
Description: Type IV emissions occur in association with major eruptions on the sun and are typically associated with strong coronal mass ejections and solar radiation storms.


Space Weather Message Code: ALTEF3
Serial Number: 2585
Issue Time: 2017 Apr 18 1241 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2584
Begin Time: 2017 Apr 17 1210 UTC
Yesterday Maximum 2MeV Flux: 1717 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: 782
Issue Time: 2017 Apr 17 1805 UTC

WATCH: Geomagnetic Storm Category G1 Predicted
Highest Storm Level Predicted by Day:
Apr 18: G1 (Minor) Apr 19: None (Below G1) Apr 20: None (Below G1)
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: 2584
Issue Time: 2017 Apr 17 1231 UTC

ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Threshold Reached: 2017 Apr 17 1210 UTC
Station: GOES13
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: 2583
Issue Time: 2017 Apr 15 1546 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2582
Begin Time: 2017 Apr 12 1115 UTC
Yesterday Maximum 2MeV Flux: 2534 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: 781
Issue Time: 2017 Apr 14 1918 UTC

WATCH: Geomagnetic Storm Category G1 Predicted
Highest Storm Level Predicted by Day:
Apr 15: None (Below G1) Apr 16: None (Below G1) Apr 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: 2582
Issue Time: 2017 Apr 14 1248 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2581
Begin Time: 2017 Apr 12 1115 UTC
Yesterday Maximum 2MeV Flux: 2552 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: 3204
Issue Time: 2017 Apr 14 1147 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3203
Valid From: 2017 Apr 14 0135 UTC
Now Valid Until: 2017 Apr 14 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: ALTK04
Serial Number: 1971
Issue Time: 2017 Apr 14 0601 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2017 Apr 14 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: 3203
Issue Time: 2017 Apr 14 0557 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3202
Valid From: 2017 Apr 14 0135 UTC
Now Valid Until: 2017 Apr 14 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: 3202
Issue Time: 2017 Apr 14 0133 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2017 Apr 14 0135 UTC
Valid To: 2017 Apr 14 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: 2581
Issue Time: 2017 Apr 13 0851 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2580
Begin Time: 2017 Apr 12 1115 UTC
Yesterday Maximum 2MeV Flux: 1800 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: 2580
Issue Time: 2017 Apr 12 1127 UTC

ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Threshold Reached: 2017 Apr 12 1115 UTC
Station: GOES13
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: 3201
Issue Time: 2017 Apr 12 0159 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2017 Apr 12 0200 UTC
Valid To: 2017 Apr 12 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: 3200
Issue Time: 2017 Apr 11 1454 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3199
Valid From: 2017 Apr 11 1030 UTC
Now Valid Until: 2017 Apr 11 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: ALTK04
Serial Number: 1970
Issue Time: 2017 Apr 11 1203 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2017 Apr 11 1159 UTC
Synoptic Period: 0900-1200 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: 3199
Issue Time: 2017 Apr 11 1030 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2017 Apr 11 1030 UTC
Valid To: 2017 Apr 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: ALTEF3
Serial Number: 2579
Issue Time: 2017 Apr 10 1121 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2578
Begin Time: 2017 Apr 09 1330 UTC
Yesterday Maximum 2MeV Flux: 3029 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: 2578
Issue Time: 2017 Apr 09 1346 UTC

ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Threshold Reached: 2017 Apr 09 1330 UTC
Station: GOES13
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: 3198
Issue Time: 2017 Apr 09 1239 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3197
Valid From: 2017 Apr 07 2348 UTC
Now Valid Until: 2017 Apr 10 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: WARK05
Serial Number: 1339
Issue Time: 2017 Apr 09 0542 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 1338
Valid From: 2017 Apr 09 0130 UTC
Now Valid Until: 2017 Apr 09 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: ALTK05
Serial Number: 1093
Issue Time: 2017 Apr 09 0458 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2017 Apr 09 0458 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: WARK05
Serial Number: 1338
Issue Time: 2017 Apr 09 0130 UTC

WARNING: Geomagnetic K-index of 5 expected
Valid From: 2017 Apr 09 0130 UTC
Valid To: 2017 Apr 09 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: 3197
Issue Time: 2017 Apr 09 0130 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3195
Valid From: 2017 Apr 07 2348 UTC
Now Valid Until: 2017 Apr 09 1300 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: 3195
Issue Time: 2017 Apr 08 1755 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3194
Valid From: 2017 Apr 07 2348 UTC
Now Valid Until: 2017 Apr 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: WARK04
Serial Number: 3194
Issue Time: 2017 Apr 08 0834 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3193
Valid From: 2017 Apr 07 2348 UTC
Now Valid Until: 2017 Apr 08 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: ALTK04
Serial Number: 1969
Issue Time: 2017 Apr 07 2355 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2017 Apr 07 2355 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: 3193
Issue Time: 2017 Apr 07 2349 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2017 Apr 07 2348 UTC
Valid To: 2017 Apr 08 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: ALTK04
Serial Number: 1968
Issue Time: 2017 Apr 06 0006 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2017 Apr 05 2359 UTC
Synoptic Period: 2100-0000 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: 3192
Issue Time: 2017 Apr 05 2250 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2017 Apr 05 2250 UTC
Valid To: 2017 Apr 06 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: SUM10R
Serial Number: 691
Issue Time: 2017 Apr 04 2155 UTC

SUMMARY: 10cm Radio Burst
Begin Time: 2017 Apr 04 2134 UTC
Maximum Time: 2017 Apr 04 2134 UTC
End Time: 2017 Apr 04 2136 UTC
Duration: 2 minutes
Peak Flux: 240 sfu
Latest Penticton Noon Flux: 94 sfu
www.swpc.noaa.gov/noaa-scales-explanation
Description: A 10cm radio burst indicates that the electromagnetic burst associated with a solar flare at the 10cm wavelength was double or greater than the initial 10cm radio background. This can be indicative of significant radio noise in association with a solar flare. This noise is generally short-lived but can cause interference for sensitive receivers including radar, GPS, and satellite communications.


Space Weather Message Code: WARK04
Serial Number: 3191
Issue Time: 2017 Apr 04 1455 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3190
Valid From: 2017 Apr 04 0440 UTC
Now Valid Until: 2017 Apr 04 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: ALTK05
Serial Number: 1092
Issue Time: 2017 Apr 04 1152 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2017 Apr 04 1152 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: ALTK05
Serial Number: 1091
Issue Time: 2017 Apr 04 0815 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2017 Apr 04 0814 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: WARK04
Serial Number: 3190
Issue Time: 2017 Apr 04 0734 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3189
Valid From: 2017 Apr 04 0440 UTC
Now Valid Until: 2017 Apr 04 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: WARK05
Serial Number: 1335
Issue Time: 2017 Apr 04 0734 UTC

WARNING: Geomagnetic K-index of 5 expected
Valid From: 2017 Apr 04 0733 UTC
Valid To: 2017 Apr 04 1200 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: 1967
Issue Time: 2017 Apr 04 0601 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2017 Apr 04 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: SUM10R
Serial Number: 690
Issue Time: 2017 Apr 04 0544 UTC

SUMMARY: 10cm Radio Burst
Begin Time: 2017 Apr 04 0520 UTC
Maximum Time: 2017 Apr 04 0520 UTC
End Time: 2017 Apr 04 0520 UTC
Duration: 1 minutes
Peak Flux: 160 sfu
Latest Penticton Noon Flux: 108 sfu
www.swpc.noaa.gov/noaa-scales-explanation
Description: A 10cm radio burst indicates that the electromagnetic burst associated with a solar flare at the 10cm wavelength was double or greater than the initial 10cm radio background. This can be indicative of significant radio noise in association with a solar flare. This noise is generally short-lived but can cause interference for sensitive receivers including radar, GPS, and satellite communications.


Space Weather Message Code: WARK04
Serial Number: 3189
Issue Time: 2017 Apr 04 0439 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2017 Apr 04 0440 UTC
Valid To: 2017 Apr 04 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: ALTTP4
Serial Number: 534
Issue Time: 2017 Apr 03 1804 UTC

ALERT: Type IV Radio Emission
Begin Time: 2017 Apr 03 1432 UTC

Comment: Delayed transmission due to comm problems
www.swpc.noaa.gov/noaa-scales-explanation
Description: Type IV emissions occur in association with major eruptions on the sun and are typically associated with strong coronal mass ejections and solar radiation storms.


Space Weather Message Code: ALTTP2
Serial Number: 1051
Issue Time: 2017 Apr 03 1803 UTC

ALERT: Type II Radio Emission
Begin Time: 2017 Apr 03 1429 UTC
Estimated Velocity: 746 km/s

Comment: Delayed transmission due to comm problems
www.swpc.noaa.gov/noaa-scales-explanation
Description: Type II emissions occur in association with eruptions on the sun and typically indicate a coronal mass ejection is associated with a flare event.


Space Weather Message Code: SUMXM5
Serial Number: 149
Issue Time: 2017 Apr 03 1447 UTC

SUMMARY: X-ray Event exceeded M5
Begin Time: 2017 Apr 03 1419 UTC
Maximum Time: 2017 Apr 03 1429 UTC
End Time: 2017 Apr 03 1434 UTC
X-ray Class: M5.8
Location: N12W71
NOAA Scale: R2 - Moderate
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Area of impact centered primarily on sub-solar point on the sunlit side of Earth.
Radio - Limited blackout of HF (high frequency) radio communication for tens of minutes.


Space Weather Message Code: ALTXMF
Serial Number: 266
Issue Time: 2017 Apr 03 1433 UTC

ALERT: X-Ray Flux exceeded M5
Threshold Reached: 2017 Apr 03 1429 UTC
NOAA Scale: R2 - Moderate
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Area of impact centered on sub-solar point on the sunlit side of Earth. Extent of blackout of HF (high frequency) radio communication dependent upon current X-ray Flux intensity. For real-time information on affected area and expected duration please see http://www.swpc.noaa.gov/products/d-region-absorption-predictions-d-rap.


Space Weather Message Code: ALTEF3
Serial Number: 2577
Issue Time: 2017 Apr 03 0500 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2576
Begin Time: 2017 Mar 28 1045 UTC
Yesterday Maximum 2MeV Flux: 62136 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: SUMXM5
Serial Number: 148
Issue Time: 2017 Apr 02 2046 UTC

SUMMARY: X-ray Event exceeded M5
Begin Time: 2017 Apr 02 2026 UTC
Maximum Time: 2017 Apr 02 2033 UTC
End Time: 2017 Apr 02 2038 UTC
X-ray Class: M5.7
Location: N12W60
NOAA Scale: R2 - Moderate
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Area of impact centered primarily on sub-solar point on the sunlit side of Earth.
Radio - Limited blackout of HF (high frequency) radio communication for tens of minutes.


Space Weather Message Code: ALTXMF
Serial Number: 265
Issue Time: 2017 Apr 02 2034 UTC

ALERT: X-Ray Flux exceeded M5
Threshold Reached: 2017 Apr 02 2032 UTC
NOAA Scale: R2 - Moderate
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Area of impact centered on sub-solar point on the sunlit side of Earth. Extent of blackout of HF (high frequency) radio communication dependent upon current X-ray Flux intensity. For real-time information on affected area and expected duration please see http://www.swpc.noaa.gov/products/d-region-absorption-predictions-d-rap.


Space Weather Message Code: SUM10R
Serial Number: 689
Issue Time: 2017 Apr 02 1308 UTC

SUMMARY: 10cm Radio Burst
Begin Time: 2017 Apr 02 1256 UTC
Maximum Time: 2017 Apr 02 1257 UTC
End Time: 2017 Apr 02 1257 UTC
Duration: 1 minutes
Peak Flux: 110 sfu
Latest Penticton Noon Flux: 101 sfu
www.swpc.noaa.gov/noaa-scales-explanation
Description: A 10cm radio burst indicates that the electromagnetic burst associated with a solar flare at the 10cm wavelength was double or greater than the initial 10cm radio background. This can be indicative of significant radio noise in association with a solar flare. This noise is generally short-lived but can cause interference for sensitive receivers including radar, GPS, and satellite communications.


Space Weather Message Code: SUMXM5
Serial Number: 147
Issue Time: 2017 Apr 02 0901 UTC

SUMMARY: X-ray Event exceeded M5
Begin Time: 2017 Apr 02 0750 UTC
Maximum Time: 2017 Apr 02 0802 UTC
End Time: 2017 Apr 02 0813 UTC
X-ray Class: M5.3
Optical Class: 2n
Location: N12W59
NOAA Scale: R2 - Moderate
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Area of impact centered primarily on sub-solar point on the sunlit side of Earth.
Radio - Limited blackout of HF (high frequency) radio communication for tens of minutes.


Space Weather Message Code: ALTTP2
Serial Number: 1050
Issue Time: 2017 Apr 02 0833 UTC

ALERT: Type II Radio Emission
Begin Time: 2017 Apr 02 0807 UTC
Estimated Velocity: 628 km/s
www.swpc.noaa.gov/noaa-scales-explanation
Description: Type II emissions occur in association with eruptions on the sun and typically indicate a coronal mass ejection is associated with a flare event.


Space Weather Message Code: ALTTP4
Serial Number: 533
Issue Time: 2017 Apr 02 0817 UTC

ALERT: Type IV Radio Emission
Begin Time: 2017 Apr 02 0800 UTC
www.swpc.noaa.gov/noaa-scales-explanation
Description: Type IV emissions occur in association with major eruptions on the sun and are typically associated with strong coronal mass ejections and solar radiation storms.


Space Weather Message Code: ALTXMF
Serial Number: 264
Issue Time: 2017 Apr 02 0801 UTC

ALERT: X-Ray Flux exceeded M5
Threshold Reached: 2017 Apr 02 0800 UTC
NOAA Scale: R2 - Moderate
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Area of impact centered on sub-solar point on the sunlit side of Earth. Extent of blackout of HF (high frequency) radio communication dependent upon current X-ray Flux intensity. For real-time information on affected area and expected duration please see http://www.swpc.noaa.gov/products/d-region-absorption-predictions-d-rap.


Space Weather Message Code: ALTEF3
Serial Number: 2576
Issue Time: 2017 Apr 02 0500 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2575
Begin Time: 2017 Mar 28 1045 UTC
Yesterday Maximum 2MeV Flux: 41365 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: 3188
Issue Time: 2017 Apr 02 0255 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3187
Valid From: 2017 Mar 27 0350 UTC
Now Valid Until: 2017 Apr 02 1300 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: ALTTP4
Serial Number: 532
Issue Time: 2017 Apr 01 2321 UTC

ALERT: Type IV Radio Emission
Begin Time: 2017 Apr 01 2150 UTC
www.swpc.noaa.gov/noaa-scales-explanation
Description: Type IV emissions occur in association with major eruptions on the sun and are typically associated with strong coronal mass ejections and solar radiation storms.


Space Weather Message Code: WARK04
Serial Number: 3187
Issue Time: 2017 Apr 01 2055 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3186
Valid From: 2017 Mar 27 0350 UTC
Now Valid Until: 2017 Apr 02 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: WARK04
Serial Number: 3186
Issue Time: 2017 Apr 01 1108 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 3185
Valid From: 2017 Mar 27 0350 UTC
Now Valid Until: 2017 Apr 01 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: 2575
Issue Time: 2017 Apr 01 0501 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2574
Begin Time: 2017 Mar 28 1045 UTC
Yesterday Maximum 2MeV Flux: 24539 pfu
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.