Geomagnetic storm reaching G2 Moderate levels in progress

Geomagnetic storm reaching G2 Moderate levels is currently in progress due to the influence of a positive polarity coronal hole high speed stream (CH HSS). 

Geomagnetic K-index of 5 (G1 Minor) threshold was first reached at 15:00 UTC on September 7. K-index of 6 (G2 Moderate) threshold was reached at 16:25 UTC.

A return to quiet levels are expected by September 9 as CH HSS effects subside.

Under G2 conditions, area of impact is primarily poleward of 55 degrees Geomagnetic Latitude. Power grid fluctuations can occur. High-latitude power systems may experience voltage alarms. Satellite orientation irregularities may occur; increased drag on low Earth-orbit satellites is possible. HF (high frequency) radio propagation can fade at higher latitudes. Aurora may be seen as low as New York to Wisconsin to Washington state.

SWPC alerts

Space Weather Message Code: ALTK05
Serial Number: 833
Issue Time: 2015 Sep 07 1505 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2015 Sep 07 1500 UTC
Synoptic Period: 1200-1500 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.

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Space Weather Message Code: ALTK06
Serial Number: 359
Issue Time: 2015 Sep 07 1622 UTC

ALERT: Geomagnetic K-index of 6
Threshold Reached: 2015 Sep 07 1625 UTC
Synoptic Period: 1500-1800 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.

Featured image credit: NOAA/SWPC.