CME impact: Geomagnetic storm reaching G3 Strong levels in progress

Geomagnetic storm reaching G3 Strong levels is currently in progress as a result of Coronal Mass Ejection (CME) impact on top of Coronal Hole High Speed Stream (CH HSS) influence.

The CME, produced by September 18th C-class solar flare, reached our planet at 06:05 UTC on September 20, a full day before it was expected. However, geomagnetic field was already disturbed by the influence of CH HSS prior to the CME arrival; G1 Minor geomagnetic storm (K-index of 5) threshold was reached at 05:59 UTC today and remained at those levels until 07:20 UTC when K-index rose to 6 (G2 Moderate geomagnetic storm).

Image credit: NOAA/SWPC

Geomagnetic K-index of 7 (G3 Strong) threshold was reached at 07:50 UTC.

Under G3 geomagnetic storm conditions, area of impact is primarily poleward of 50 degrees Geomagnetic Latitude. Power system voltage irregularities are 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. Intermittent satellite navigation (GPS) problems, including loss-of-lock and increased range error may occur. HF (high frequency) radio may be intermittent. Aurora may be seen as low as Pennsylvania to Iowa to Oregon.

This phase of strong storming was over by 10:00 UTC when K-index measured 5 (G1 Minor) again.

Further enhancement is possible throughout the day and tomorrow (September 20 – 21).

Image credit: NOAA/SWPC

WSA – ENLIL model, September 18th CME impact forecast. Image credit: NOAA/SWPC

Image credit: NOAA/SWPC

SWPC alerts

Space Weather Message Code: ALTK05
Serial Number: 851
Issue Time: 2015 Sep 20 0602 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2015 Sep 20 0559 UTC
Synoptic Period: 0300-0600 UTC

Active Warning: Yes
NOAA Scale: G1 – Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents – Weak power 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: SUMSUD
Serial Number: 212
Issue Time: 2015 Sep 20 0612 UTC

SUMMARY: Geomagnetic Sudden Impulse
Observed: 2015 Sep 20 0605 UTC
Deviation: 27 nT
Station: Boulder

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

***

Space Weather Message Code: ALTK05
Serial Number: 852
Issue Time: 2015 Sep 20 0705 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2015 Sep 20 0705 UTC
Synoptic Period: 0600-0900 UTC

Active Warning: Yes
NOAA Scale: G1 – Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents – Weak power 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: 373
Issue Time: 2015 Sep 20 0721 UTC

ALERT: Geomagnetic K-index of 6
Threshold Reached: 2015 Sep 20 0720 UTC
Synoptic Period: 0600-0900 UTC

Active Warning: Yes
NOAA Scale: G2 – Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 55 degrees Geomagnetic Latitude.
Induced Currents – 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: ALTK07
Serial Number: 99
Issue Time: 2015 Sep 20 0750 UTC

ALERT: Geomagnetic K-index of 7
Threshold Reached: 2015 Sep 20 0750 UTC
Synoptic Period: 0600-0900 UTC

Active Warning: Yes
NOAA Scale: G3 – Strong

NOAA Space Weather Scale descriptions can be found at
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: ALTK05
Serial Number: 853
Issue Time: 2015 Sep 20 1001 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2015 Sep 20 1000 UTC
Synoptic Period: 0900-1200 UTC

Active Warning: Yes
NOAA Scale: G1 – Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents – Weak power 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.

Featured image credit: Zoltan Kenwell (InFocusImagery)