Viewing archive of Wednesday, 3 December 2025

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2025 Dec 03 1237 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Minor storm expected (A>=30 or K=5)

Solar protons

Warning condition (activity levels expected to increase, but no numeric forecast given)

	10cm flux	Ap
03 Dec 2025	202	021
04 Dec 2025	202	018
05 Dec 2025	200	014

Solar Active Regions and flaring

Solar flaring activity over the past 24 hours was at low levels with only C-class flares identified. The strongest activity was a C5.4 flare (SIDC Flare 6271) with peak time 20:38 UTC on on Dec 02, produced by SIDC Sunspot Group 703 (NOAA Active Region 4288). The region is classified as magnetic type beta and is currently approaching the west limb. A total of 11 sunspot groups were identified on the visible solar disk. SIDC Sunspot Group 709 (NOAA Active Region 4294) and SIDC Sunspot Group 687 (NOAA Active Region 4299) are the most complex regions, both classified as magnetic type beta-delta. The latter regions together with SIDC Sunspot Group 703 and SIDC Sunspot Group 713 (NOAA Active Region 4298) were responsible for most of the flaring activity throughout the past 24 hours. The solar flaring activity is expected to be at moderate levels over the next 24 hours with background C-class flaring, likely M-class flares and chances of isolated X-class flaring.

Coronal mass ejections

A large filament eruption is visible in the SDO/AIA 30.4 nm imagery in the western solar hemisphere, lifting off the solar surface around 10 UTC on Dec 03. Coronagraph imagery is awaited to estimate any possible Earth-directed coronal mass ejection (CME) related to this eruption. No other Earth-directed 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) were indicative of background slow solar wind conditions throughout Dec 02 and have registered small enhancements in the UTC morning of Dec 03. The registered solar wind speed was in the range of 353 km/s to 538 km/s. The magnitude of the interplanetary magnetic field, B, has increased up 12.2 nT and a minimum Bz component of - 9.3 nT. The B field phi angle was predominantly in the positive sector (directed away from the Sun). The solar wind conditions are expected to register a mild high speed stream arrival related to a negative polarity coronal hole (CH SIDC 140), possibly mixed with a minor glancing blow influence from the partial halo CME associated with the X1.9-flare on Dec 01.

Geomagnetism

The geomagnetic conditions over the past 24 hours were quiet to unsettled. Predominantly unsettled to active conditions are expected for Dec 03 and Dec 04 with likely isolated minor storms and small chances for reaching moderate storm levels later on Dec 03.

Proton flux levels

Over the past 24 hours the greater than 10 MeV GOES proton flux has been at nominal levels and is expected to remain so over the next days with chances for some enhancements in case of new strong flaring and eruptive activity.

Electron fluxes at geostationary orbit

The greater than 10 MeV electron flux (as measured by GOES 18 and GOES 19) has exceeded the 1000 pfu threshold over the last 24 hours and is expected to exceed the 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): 173, based on 06 stations.

Solar indices for 02 Dec 2025

Wolf number Catania	217
10cm solar flux	200
AK Chambon La Forêt	013
AK Wingst	013
Estimated Ap	010
Estimated international sunspot number	170 - 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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