Viewing archive of Saturday, 17 January 2026

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2026 Jan 17 1231 UTC

SIDC Forecast

Solar flares

M-class flares expected (probability >=50%)

Geomagnetism

Active conditions expected (A>=20 or K=4)

Solar protons

Quiet

	10cm flux	Ap
17 Jan 2026	148	016
18 Jan 2026	150	031
19 Jan 2026	148	027

Solar Active Regions and flaring

Solar flaring activity was moderate over the past 24 hours, with only one M-class flares identified. The largest flare was a M2.2 flare peaking on January 16 at 10:29 UTC, which was produced by SIDC Sunspot Group 740 (NOAA Active Region 4341). A total of 9 numbered sunspot groups were identified on the disk over the past 24 hours. SIDC Sunspot Group 763 (NOAA Active Region 4343) is the most complex active region and has a Beta-Gamma-Delta magnetic configuration. Solar flaring activity is expected to be moderate over the next 24 hours, with M-class flares very likely and a small chance for X-class flares.

Coronal mass ejections

No new Earth-directed Coronal Mass Ejections (CMEs) have been detected in the available coronagraph images. The CME seen in LASCO C2 data at 02:36 UTC on Jan 17 will be further analysed.

Coronal holes

SIDC Coronal Hole 146 (a large equatorial coronal hole with a positive polarity) continues it's crossing of the central meridian. High Speed Stream from this coronal hole is expected to impact earth on the 18th of January.

Solar wind

Fast solar wind conditions were recorded over the last 24 hours with speeds peaking at 740 Km/s, and currently at around 700 km/s. The interplanetary magnetic field was around 13 nT till Jan 17 02:00 UTC then reduced to 8nT. Bz reached a minimum value of -12 nT. Fast Solar wind speeds are expected for the next 24h, due to the possible arrival of the High Speed stream of SIDC CH 146.

Geomagnetism

Both locally and globally, the geomagnetic activity were Active to Minor Storm (Kp 5+ between Jan 16 15:00 UTC to 18:00 UTC and Jan 16 21:00 UTC to Jan 17 00:00 UTC). Active to Minor storm levels are expected for the next 24h.

Proton flux levels

The greater than 10 MeV proton flux remained below the 10 pfu threshold and is expected to remain so over the next days.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux remained below the 1000 pfu alert threshold, but may increase above the threshold during the next 24 hours under the influence of the high speed stream. The 24h electron fluence was decreasing but still at moderate levels and is expected to decrease to normal levels.

Today's estimated international sunspot number (ISN): 136, based on 09 stations.

Solar indices for 16 Jan 2026

Wolf number Catania	///
10cm solar flux	148
AK Chambon La Forêt	046
AK Wingst	026
Estimated Ap	029
Estimated international sunspot number	142 - Based on 15 stations

Noticeable events summary

Provided by the Solar Influences Data analysis Center© - SIDC - Processed by SpaceWeatherLive

All times in UTC

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