Viewing archive of Monday, 19 January 2026

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2026 Jan 19 1302 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

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

Solar protons

Proton event in progress (>10 MeV)

	10cm flux	Ap
19 Jan 2026	152	022
20 Jan 2026	152	057
21 Jan 2026	152	017

Solar Active Regions and flaring

Solar flaring activity was high over the past 24 hours, with one X-class flare and two M-class flares observed. The largest event was an X1.9 flare (SIDC Flare 6678), peaking on 2026 Jan 18 at 18:09 UTC, produced by SIDC Sunspot Group 740 (NOAA AR 4341). Nearly simultaneously, a Type II radio emission began at 2026 Jan 18 17:59 UTC, indicating shock formation and supporting the presence of an associated coronal mass ejection (CME). The same region also produced an M1.2 flare (SIDC Flare 6681) peaking on 2026 Jan 18 at 21:47 UTC and an M1.1 flare (SIDC Flare 6682) peaking on 2026 Jan 19 at 11:19 UTC. SIDC Sunspot Group 740 is currently located near S16E21, has a Beta-Gamma magnetic configuration, and continued to grow over the past 24 hours. Another complex region, SIDC Sunspot Group 763 (NOAA AR 4343), also shows a Beta- Gamma configuration but displayed signs of decay during the same period. Over the next 24 hours, solar flaring activity is expected to be moderate, with M-class flares likely and a small chance of additional X-class flaring.

Coronal mass ejections

A full-halo coronal mass ejection (CME; angular width about 360 degrees) was detected in SOHO/LASCO C2 data on 2026 Jan 18 at 18:12 UTC. It is associated with the X1.9 flare (SIDC Flare 6678), peaking on 2026 Jan 18 at 18:09 UTC, produced by SIDC Sunspot Group 740 (NOAA AR 4341). Given the source location and the close association with the flare and the Type II emission, the CME is considered Earth-directed. The plane-of-sky speed is estimated at 1000 to 1500 km/s with an arrival expected later today or tomorrow. A more precise arrival-time estimate is currently being evaluated.

Coronal holes

SIDC Coronal Hole 146 (a large trans equatorial coronal hole with a positive polarity) continues it's crossing of the central meridian.

Solar wind

Over the past 24 hours, Earth remained under a high-speed stream linked to SIDC Coronal Hole 146, a large trans-equatorial coronal hole with positive polarity. Solar wind speeds reached about 770 km/s but showed a gradual decay, trending toward roughly 500 km/s to 600 km/s. The interplanetary magnetic field (IMF) stayed moderately enhanced, with the totla IMF (Bt) below about 9 nT, while IMF southward component (Bz) fluctuated between about -6.3 nT and +7.2 nT. The magnetic field orientation remained well connected to the positive sector, with the phi angle staying consistent with the positive polarity source, so solar wind speeds may remain elevated over the next 24 hours. Later today or tomorrow, a solar wind shock is expected with the arrival of SIDC CME 624, first detected as a full halo in SOHO/LASCO C2 on 2026 Jan 18 at 18:12 UTC and associated with the X1.9 flare (SIDC Flare 6678).

Geomagnetism

Geomagnetic conditions were mostly active in response to the high-speed stream, with NOAA Kp reaching 4 and the local K index in Belgium also reaching 4. Unsettled to active conditions are expected to continue in the coming hours. With the anticipated arrival of the fast CME and its associated shock, a geomagnetic storm is possible, with activity potentially rising to about Kp 7 to 8.

Proton flux levels

A proton event is associated with the X1.9 flare (SIDC Flare 6678) peaking on 2026 Jan 18 at 18:09 UTC, produced by SIDC Sunspot Group 740 (NOAA AR 4321 and 4341): the greater than 10 MeV GOES proton flux has been above the 10 pfu threshold since 2026 Jan 18 at 22:50 UTC and is still increasing, with the 100 pfu level exceeded from 2026 Jan 19 at 04:40 UTC. The proton flux continues to rise, and the greater than 100 MeV GOES proton flux also shows a slight increase starting on 2026 Jan 19 at 10:40 UTC. The greater than 10 MeV and the greater than 100 MeV GOES proton fluxes are 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, in response to the high solar wind speed stream. The 24h electron fluence was at moderate levels and is expected to decrease to normal levels.

Today's estimated international sunspot number (ISN): 161, based on 13 stations.

Solar indices for 18 Jan 2026

Wolf number Catania	///
10cm solar flux	148
AK Chambon La Forêt	022
AK Wingst	018
Estimated Ap	017
Estimated international sunspot number	143 - Based on 10 stations

Noticeable events summary

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

All times in UTC

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