Viewing archive of Tuesday, 20 January 2026

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2026 Jan 20 0858 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
18 Jan 2026	150	022
19 Jan 2026	150	017
20 Jan 2026	152	017

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 M1.2 flare peaking on January 17 at 23:51 UTC, which was produced by SIDC Sunspot Group 740 (NOAA Active Region 4341). A total of 8 numbered sunspot groups were identified on the disk over the past 24 hours. SIDC Sunspot Group 763 (NOAA Active Region 4343) (beta-gamma) and SIDC Sunspot Group 740 (NOAA Active Region 4341) (beta-gamma) are the most complex active regions. 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.

Coronal holes

The mid-latitude part of the large positive polarity SIDC Coronal Hole 146 continues it's crossing of the central meridian.

Solar wind

Fast solar wind conditions were recorded over the last 24 hours with speeds peaking at 740 Km/s, and are reducing and currently at around 560 km/s. The interplanetary magnetic field was around 9 nT. Bz reached a minimum value of -6 nT. Fast Solar wind speeds are expected for the next 24h, due to High Speed stream of SIDC CH 146.

Geomagnetism

Geomagnetic activity were unsettled to Active (Kp 4) over the past 24h. Unsettled to Active conditions are expected for the next 24h.

Proton flux levels

The greater than 10 MeV proton flux was below the 10 pfu threshold level over the past 24 hours. It is expected to remain below the threshold level over the next 24 hours.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux was above the 1000 pfu alert threshold since 17 Jan 13:30, and is expected to remain above the threshold for the next 24 hours. The 24h electron fluence was at moderate levels and is expected to remain at moderate levels.

Today's estimated international sunspot number (ISN): 144, based on 15 stations.

Solar indices for 17 Jan 2026

Wolf number Catania	///
10cm solar flux	159
AK Chambon La Forêt	034
AK Wingst	028
Estimated Ap	029
Estimated international sunspot number	134 - Based on 16 stations

Noticeable events summary

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

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2026 Jan 20 1247 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Major (ISES: Severe) magstorm expected (A>=100 or K>=7)

Solar protons

Proton event in progress (>10 MeV)

	10cm flux	Ap
20 Jan 2026	176	060
21 Jan 2026	176	012
22 Jan 2026	176	007

Solar Active Regions and flaring

Solar flaring activity was somewhat low over the past 24 hours, with only C-class flares identified. The largest flare was a C8.0 flare (SIDC Flare 6695) peaking on January 19 at 19:21 UTC, produced by SIDC Sunspot Group 740 (NOAA Active Region 4341). SIDC Sunspot Group 740 is now located at S10W00 with a Beta-Gamma magnetic configuration and was stable over the past 24 hours. SIDC Sunspot Group 766 (NOAA Active Region 4345) grew over the past 24 hours and has a Beta-Gamma- Delta magnetic configuration. This region was the most active over the past 24 hours and produced most of the C-class flares. Solar flaring activity is expected to be moderate over the next 24 hours, with C-class flares expected and M-class flares likely.

Coronal mass ejections

No Earth-directed coronal mass ejections (CMEs) were observed in SOHO/LASCO images over the past 24 hours. Due to contamination from the ongoing particle event, the CACTus tool automatically reported several halo CMEs between 2026 Jan 19 11:48 UTC and 15:36 UTC; these detections are false alerts.

Coronal holes

SIDC Coronal Hole 146, a large trans-equatorial coronal hole with positive polarity, continues to cross the central meridian.

Solar wind

The interplanetary CME (ICME) associated with the full-halo CME observed in SOHO/LASCO C2 on 2026 Jan 18 at 18:12 UTC (linked to the X1.9 flare, SIDC Flare 6678, peaking at 18:09 UTC from SIDC Sunspot Group 740, NOAA AR 4341, and accompanied by Type II radio emission) arrived at Earth significantly earlier than anticipated. The shock arrival is best timed from the jump in the interplanetary magnetic field (IMF), observed around 19:00 UTC by ACE and consistent with DSCOVR magnetic field data. Plasma measurements, including solar wind speed, were strongly disturbed by the ongoing solar energetic particle (SEP) event, so the early speed values are not reliable until around 21:14 UTC. After the shock, the north-south IMF component, Bz, gradually turned strongly southward, reaching about -58 nT at 21:04 UTC, before rapidly rotating northward to around +50 nT and remaining predominantly positive for several hours. Once the plasma data recovered, the ICME speed near Earth was around 1100 km/s, implying a Sun to Earth transit time of roughly 25 hours. Current observations indicate that solar wind speeds remain elevated near 900 km/s to 1000 km/s, while the total IMF has decreased to around 12 nT. Bz turned southward again around 05:30 UTC, reaching about -20 nT. Elevated solar wind speeds are expected to persist through the next day while the ICME continues to pass, after which conditions should gradually return toward a slower, more typical solar wind regime.

Geomagnetism

Over the past 24 hours, geomagnetic conditions escalated from quiet to severe storm levels following the arrival of an interplanetary shock and a strong southward turning of the interplanetary magnetic field (IMF). The main driver was the north-south IMF component, Bz, which turned negative and reached strongly southward values, enabling efficient coupling between the solar wind and Earth’s magnetosphere and triggering a rapid intensification of geomagnetic activity. Locally, the Belgian K index (K_BEL) started to increase around 19:00 UTC, reached 8 by 21:00 UTC, and peaked at 9 at 22:00 UTC, indicating an extremely severe storm interval. Globally, the NOAA Kp index reached 8 for the 18:00 to 21:00 UTC three-hour interval and increased further to 9- for 21:00 to 24:00 UTC, consistent with a severe geomagnetic storm driven by the CME impact and its strongly southward magnetic field. Geomagnetic conditions again reached severe storm levels globally (NOAA Kp = 8-) between 06:00 and 09:00 UTC on January 20, following a prolonged period of negative Bz. Locally, moderate storm conditions were observed over Belgium (K_BEL = 6). With solar wind speeds still high, around 950 km/s, further major to severe storm intervals remain possible while Earth continues to be influenced by the ICME.

Proton flux levels

The solar energetic particle event associated with the X1.9 flare (SIDC Flare 6678, peaking on 2026 Jan 18 at 18:09 UTC) is still ongoing. The greater than 10 MeV GOES proton flux has been above the 10 pfu threshold since 2026 Jan 18 at 22:50 UTC and remains above it. The greater than 10 MeV GOES proton flux is expected to remain elevated over the next 24 hours.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux remained slightly above the 1000 pfu alert threshold until 2026 Jan 19 at 08:00 UTC, in response to the high-speed solar wind stream. It then fell below the threshold. With the solar wind speed still elevated, the greater than 2 MeV electron flux is expected to increase again and may cross the threshold once the geomagnetic storm begins to subside. The 24-hour electron fluence was at moderate levels and is expected to decrease but remain at moderate levels.

Today's estimated international sunspot number (ISN): 176, based on 12 stations.

Solar indices for 19 Jan 2026

Wolf number Catania	///
10cm solar flux	173
AK Chambon La Forêt	109
AK Wingst	087
Estimated Ap	103
Estimated international sunspot number	168 - Based on 17 stations

Noticeable events summary

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

All times in UTC

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