Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2025 Dec 06 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

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

Solar protons

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

	10cm flux	Ap
06 Dec 2025	204	011
07 Dec 2025	202	007
08 Dec 2025	200	007

Solar Active Regions and flaring

Solar flaring activity over the past 24 hours was low with only C-class flares identified. The strongest activity was a C6.4 flare (SIDC Flare 6304) with peak time 03:09 UTC on Dec 06 associated with SIDC Sunspot Group 709 (NOAA Active Regions 4294). A total of 8 numbered sunspot groups were identified on the visible solar disk. SIDC Sunspot Group 709 (NOAA Active Region 4294) and SIDC Sunspot Group 712 (NOAA Active Region 4296) remain the largest regions, which produced most of the observed flaring activity. They are classified respectively as magnetic type beta-gamma-delta and magnetic type beta-delta. SIDC Sunspot Group 687 (NOAA Active Region 4299) has increased its underlying magnetic field complexity and is currently classified as magnetic type beta-gamma- delta. It has produced a C5.2 flare with peak time 22:48 UTC on Dec 06. The remaining regions have been mostly simple and quiet. 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 small chances of isolated X-class flaring.

Coronal mass ejections

No other 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) continued to register the influence of an ongoing high-speed stream. The solar wind speed remained rather fast with a recorded maximum value of 730 km/s. The magnitude of the interplanetary magnetic field, B, was mildly elevated registering values of up to 8 nT. The Bz component was relative weak with a minimum value of -6.3 nT. The B field phi angle was predominantly in the negative sector (directed towards the Sun) reflecting the polarity of the geo-effective coronal hole (SIDC 140). The solar wind conditions are expected to remain elevated over the next days under the ongoing influence of the high-speed stream with chances for additional minor enhancements on Dec 06 and Dec 07 related to any possible glancing blow influence from the modelled CMEs, which launched from the Sun on Dec 03 and Dec 04.

Geomagnetism

The geomagnetic conditions over the past 24 hours were quiet to active. Quiet at active conditions are expected to prevail over the next 24 hours with remaining chances for isolated minor storm levels due to an ongoing influence of a high speed stream mixed with any possible minor glancing blow.

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 small chances for some enhancements related to possible high flaring activity.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux (as measured by GOES 18 and GOES 19) has briefly exceeded the 1000 pfu threshold over the last 24 hours. It is exceed to exceed the 1000 pfu threshold again in the next 24 hours. The 24-hour electron fluence was at nominal levels and is expected to increase towards moderate levels over the next 24 hours and remain at moderate levels over the next days.

Today's estimated international sunspot number (ISN): 159, based on 04 stations.

Solar indices for 05 Dec 2025

Wolf number Catania	223
10cm solar flux	206
AK Chambon La Forêt	023
AK Wingst	016
Estimated Ap	015
Estimated international sunspot number	167 - Based on 14 stations

Noticeable events summary

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