A G2 – Moderate geomagnetic storm is in progress following the arrival of a coronal hole high speed stream (CH HSS) that enhanced solar wind speeds and magnetic field fluctuations.
This geomagnetic disturbance may cause minor but noticeable operational effects at high latitudes. Power systems could experience voltage fluctuations or alarms, and low Earth-orbit satellites may require attitude corrections due to increased atmospheric drag. High-frequency radio communications may experience fading across polar and auroral regions.
Auroral visibility may extend southward to latitudes near New York, Wisconsin, and Washington state during local night hours, depending on sky clarity and geomagnetic orientation.
Long northern winter nights provide favorable viewing conditions across Canada, Alaska, the northern tier of the United States, and extend across much of northern Europe, including Iceland, Norway, Sweden, and Finland.
Forecast models suggest the geomagnetic field is likely to remain active on February 17, followed by quieter to unsettled conditions on February 18 as the high speed stream influence weakens.
Coronal holes recurrently release fast solar wind streams that interact with Earth’s magnetic field, producing moderate storms like the current one. Such disturbances are routine features of the solar cycle’s active phase.
They periodically enhance solar wind pressure and magnetic field fluctuations but generally do not produce significant geomagnetic disturbances beyond G2 levels when unaccompanied by large coronal mass ejections (CMEs).
In 24 hours to 12:30 UTC, the solar wind showed speeds initially near 750 km/s and decreasing to 550–600 km/s by the end of the period. The total magnetic field strength peaked at 9 nT, with the southward Bz component reaching −7 nT, sufficient to sustain magnetospheric coupling and auroral activity.
The solar wind environment remains influenced by a positive polarity coronal hole stream expected to persist through February 18.
Electron flux above 2 MeV reached moderate levels and is forecast to increase to high levels on February 17–18, while proton flux above 10 MeV remains at background values.
Solar activity on February 16 included an M2.5 flare detected at 04:35 UTC from a region beyond the east limb of the Sun. The CME is not Earth-directed.
Solar activity is expected to be at low levels through February 18, with a slight chance for M-class flares.