Viewing archive of Saturday, 6 September 2025

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2025 Sep 06 1231 UTC

SIDC Forecast

Solar flares

C-class flares expected, (probability >=50%)

Geomagnetism

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

Solar protons

Quiet

	10cm flux	Ap
06 Sep 2025	141	013
07 Sep 2025	138	010
08 Sep 2025	134	007

Solar Active Regions and flaring

Solar flaring activity was low over the past 24 hours, with only C-class flares identified. The largest flare was a C4.9 flare (SIDC Flare 5440) peaking on September 06 at 10:41 UTC, which was produced by SIDC Sunspot Group 614 (NOAA Active Region 4197). A total of 10 numbered sunspot groups were identified on the disk over the past 24 hours. SIDC Sunspot Group 624 (NOAA Active Region 4207) is the largest and most magnetically complex (Beta-Gamma) region on disk. Solar flaring activity is expected to be low over the next 24 hours, with C-class flares very likely and a chance for M-class flares.

Coronal mass ejections

No Earth-directed Coronal Mass Ejections (CMEs) have been detected in the available coronagraph images.

Solar wind

Over the past 24 hours, the solar wind conditions at Earth became mildly disturbed, due to the arrival of a high-speed stream (HHS) associated with SIDC Coronal Hole 123. The solar wind speed gradually rose from a speed around 400 km/s to 520 km/s. The total interplanetary magnetic field ranged from 8 nT to 13 nT, with the Bz reaching a minimum of -8 nT. The phi-angle was mainly in the positive sector (directed away from the Sun), with periods in the negative sector. The solar wind conditions are expected to become more disturbed in the next 24 hours, due to the expected arrival of a high-speed stream associated with SIDC Coronal Hole 128.

Geomagnetism

The geomagnetic conditions over the past 24 hours reached active conditions globally and locally (Kp 4 & K BEL 4). Active to minor storm condition are expected for the next 24 hours.

Proton flux levels

Over the past 24 hours, the greater than 10 MeV GOES proton was at background levels and is expected to remain so over the next days.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux, as measured by the GOES-18 crossed the 1000 pfu threshold between 18:55 UTC on September 05 and 22:50 UTC on September 05. The greater than 2 MeV electron flux, as measured by the GOES-19 satellites, was elevated but stayed below the 1000 pfu threshold in the last 24 hours. The 2 MeV electron flux is expected to cross the threshold again during the next 24 hour. The 24-hour electron fluence was at normal levels and is expected to remain at normal levels over the next 24 hours.

Today's estimated international sunspot number (ISN): 117, based on 11 stations.

Solar indices for 05 Sep 2025

Wolf number Catania	151
10cm solar flux	149
AK Chambon La Forêt	018
AK Wingst	009
Estimated Ap	009
Estimated international sunspot number	146 - Based on 28 stations

Noticeable events summary

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

All times in UTC

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