Viewing archive of Friday, 28 November 2025

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2025 Nov 28 1231 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
28 Nov 2025	127	016
29 Nov 2025	135	015
30 Nov 2025	150	012

Solar Active Regions and flaring

Solar flaring activity was low over the past 24 hours, with only C-class flares identified. SIDC Sunspot Group (SG) 709 has produced almost all the C-class flaring activity, although it is currently rotating into Earth's view and hence partially obstructed by the solar limb. The brightest flare of the past 24 hours was SIDC flare 6221, a C5, that peaked on 28 Nov at 05:54 UTC and is associated with the same SG. Although SIDC SG 709's magnetic configuration and development cannot currently be established, it is estimated that it will likely produce M-class flaring activity in the next 24 hours. There is also a small change of an X-class flare from the same SG.

Coronal mass ejections

No Earth-directed Coronal Mass Ejections (CME) were observed in the last 24 hours.

Coronal holes

SIDC Coronal Hole 139 (a mid-latitude coronal hole with positive polarity) first reached the central meridian on November 28 and is now positioned on the eastern side of the Sun. Due to its small size and irregular shape there is only a small chance that an associated High Speed Stream (HSS) will reach the Earth's environment. If this effect materializes, it will not be before 2 Dec.

Solar wind

Over the past 24 hours, solar wind parameters (ACE and DSCOVR) reflected the waning influence of a high-speed stream (HSS). The solar wind speed gradually decreased from about 700 km/s to 600 km/s. The interplanetary magnetic field (B) varied between 4 and 8 nT and its North- South component (Bz) fluctuated between -6 and 4 nT. The SW speed is expected to continue its slow decline and the magnetic field is expected continue at similar levels in the next 24 hours.

Geomagnetism

Both the global and local geomagnetic conditions reached minor storm levels (NOAA Kp 5- and K BEL 5) on Nov 27 at 18:00-21:00 UTC. For the rest of the past 24 hours, they were ranging between unsettled and active levels (NOAA Kp 3+ to 4, K BEL 3 to 4). The geomagnetic conditions of the next 24 hours are expected to follow a similar pattern, of mostly active levels with possibly short intervals of minor storm conditions.

Proton flux levels

The greater than 10 MeV proton flux, as measured by the GOES-19 satellite, was at background levels over the past 24 hours and is likely to remain so in the next 24 hours. Nevertheless there is a small chance that a proton event, associated with SIDC SG 709, might occur during the next 24 hours.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux, as measured by GOES-19, was above the 1000 pfu threshold during the past 24 hours with a peak value of 8200 pfu on 27 Nov at 13:05 UTC. The electron flux is expected to continue exceeding this threshold over the next day. The 24-hour electron fluence was at moderate levels during the past 24 hours. It is expected to feature a small increase in the next 24 hours and possibly reach high levels.

Today's estimated international sunspot number (ISN): 084, based on 13 stations.

Solar indices for 27 Nov 2025

Wolf number Catania	134
10cm solar flux	120
AK Chambon La Forêt	038
AK Wingst	026
Estimated Ap	028
Estimated international sunspot number	093 - Based on 15 stations

Noticeable events summary

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

All times in UTC

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