Viewing archive of Wednesday, 28 January 2026

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2026 Jan 28 1237 UTC

SIDC Forecast

Solar flares

C-class flares expected, (probability >=50%)

Geomagnetism

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

Solar protons

Quiet

	10cm flux	Ap
28 Jan 2026	142	013
29 Jan 2026	139	010
30 Jan 2026	136	004

Solar Active Regions and flaring

Solar flaring activity was low over the past 24 hours, with only C-class flares identified. A total of 11 numbered sunspot groups were identified on the visible solar disk over the past 24 hours. All regions are magnetically simple, classified either as magnetic type alpha or beta. The strongest activity was a C2.7 flare (SIDC Flare 6748) with peak time 23:40 UTC on Jan 27, produced by SIDC Sunspot Group 762 (NOAA Active Region 4342), which has rotated behind the west limb. The solar flaring activity is expected to be at low levels over the next 24 hours with likely C-class flares and 40% chances for M-class flaring.

Coronal mass ejections

No Earth-directed coronal mass ejections (CMEs) have been identified in the available coronagraph imagery over the past 24 hours.

Solar wind

Over the past 24 hours the solar wind parameters (as measured by ACE at L1) have register an anticipated high speed stream arrival, most probably related to the negative polarity coronal hole (SIDC 147). The solar wind speed has increased to about 660 km/s, though the density has been very low causing a large uncertainty in the measurements. The magnitude of the interplanetary magnetic field (B) remained moderately elevated with a maximum value of 11.6 nT and a minimum north-south (Bz) component of - 9.8 nT. The B field phi angle has switched to the positive sector (directed towards the Sun) possibly reflecting the polarity of the geo-effective CH 147. The solar wind conditions are expected to remain elevated over the next 24 hours before they start to decline towards nominal slow solar wind.

Geomagnetism

The geomagnetic conditions over the past 24 hours were quiet to unsettled. Quiet to active geomagnetic conditions with chances for isolated minor storm levels are expected for the next 24 hours in relation to an ongoing high speed stream arrival.

Proton flux levels

Over the past 24 hours the greater than 10 MeV GOES proton flux at nominal levels. The greater than 10 MeV GOES proton flux is expected to be at nominal levels over the next days.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux as measured by GOES 19 was oscillating around the 1000 pfu threshold the past 24 hours, currently registering values above the threshold. The greater than 2 MeV electron flux as measured by GOES 19 is expected to exceed the 1000 pfu threshold again over the next 24 hours. The 24-hour electron fluence was at moderate levels and is expected to remain so over the next 24 hours.

Today's estimated international sunspot number (ISN): 117, based on 06 stations.

Solar indices for 27 Jan 2026

Wolf number Catania	111
10cm solar flux	144
AK Chambon La Forêt	023
AK Wingst	012
Estimated Ap	011
Estimated international sunspot number	108 - Based on 08 stations

Noticeable events summary

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

All times in UTC

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