Earth under the influence of high speed solar wind stream


Earth is currently under the influence of a high speed solar wind stream originating in large southern coronal hole. Although the bulk of this stream is headed south of our planet, we have already experienced severe geomagnetic storm periods at high latitudes.

Geomagnetic K-index of 5 (G1-Minor) threshold was reached at 17:42 UTC on January 4, 2015. 

Area of impact is primarily poleward of 60 degrees Geomagnetic Latitude. Weak power grid fluctuations can occur during G1 storming as well as minor impact on satellite operations. Aurora may be visible at high latitudes.

Space Weather Message Code: ALTK05
Serial Number: 765
Issue Time: 2015 Jan 04 1742 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2015 Jan 04 1742 UTC
Synoptic Period: 1500-1800 UTC
Active Warning: Yes
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at

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.

Geomagnetic Activity Probabilities for January 4, 5 and 6, 2015 (SWPC)

- Middle Latitudes -

Active                30/30/20 (%)
Minor Storm           15/15/05 (%)
Major-severe storm    01/01/01 (%)

- High Latitudes -

Active                15/15/15 (%)
Minor Storm           30/30/25 (%)
Major-severe storm    40/40/25 (%)

The solar wind environment at the ACE spacecraft is expected to continue to reflect the episodic influence of the southern coronal hole high speed stream.

3-day ACE RTSW (MAG&SWEPAM). Image credit: SWPC

The geomagnetic field is expected to be unsettled to active with a slight chance for minor storm (G1-Minor) levels on January 4 and 5 in response to the high speed solar wind stream.

Quiet to unsettled levels are expected on January 6 as the high speed stream influence wanes.

Featured image credit: Zoltan Kenwell (InFocusImagery)


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