Viewing archive of Thursday, 28 August 2025
Daily bulletin on solar and geomagnetic activity from the SIDC
Issued: 2025 Aug 28 1231 UTC
SIDC Forecast
Solar flares
M-class flares expected (probability >=50%)
Geomagnetism
Quiet (A<20 and K<4)
Solar protons
Quiet
| 10cm flux | Ap | |
|---|---|---|
| 28 Aug 2025 | 226 | 007 |
| 29 Aug 2025 | 226 | 007 |
| 30 Aug 2025 | 226 | 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 C9.2 flare (SIDC Flare 5247) peaking on August 27 at 12:50 UTC, which was produced by SIDC Sunspot Group 617 (NOAA Active Region 4199). A total of 14 numbered sunspot groups were identified on the disk over the past 24 hours. Solar flaring activity is expected to be low to moderate over the next 24 hours, with C-class flares expected and a chance for M-class flares.
Coronal mass ejections
No Earth-directed Coronal Mass Ejections (CMEs) have been observed in the last 24 hours.
Solar wind
The Earth is inside slow solar wind with speeds around 400 km/s and interplanetary magnetic fields of about 7 nT (directed towards the Sun, negative polarity). Similar conditions can be expected for the coming 24 hours.
Geomagnetism
Geomagnetic conditions have been quiet to unsettled (Kp and B_Bel between 0 and 3). Similar conditions are expected for the next 24 hours.
Proton flux levels
The greater than 10 MeV proton flux returned to nominal levels (below the 10 pfu threshold) at 15:30 UT on 27 August. It is expected to remain at nominal levels.
Electron fluxes at geostationary orbit
The greater than 2 MeV electron flux as measured by GOES 18 and 19 remained below the 1000 pfu alert threshold, similar conditions expected for the next 24 hours. The 24 h electron fluence was at normal levels and is expected to remain so.
Today's estimated international sunspot number (ISN): 209, based on 10 stations.
Solar indices for 27 Aug 2025
| Wolf number Catania | 173 |
| 10cm solar flux | 226 |
| AK Chambon La Forêt | 016 |
| AK Wingst | 009 |
| Estimated Ap | 009 |
| Estimated international sunspot number | 207 - Based on 20 stations |
Noticeable events summary
| Day | Begin | Max | End | Loc | Strength | OP | 10cm | Catania/NOAA | Radio burst types | |
|---|---|---|---|---|---|---|---|---|---|---|
| None | ||||||||||
Provided by the Solar Influences Data analysis Center© - SIDC - Processed by SpaceWeatherLive
All times in UTC
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