Viewing archive of Wednesday, 20 August 2025

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2025 Aug 20 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

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

Solar protons

Quiet

	10cm flux	Ap
20 Aug 2025	116	022
21 Aug 2025	118	017
22 Aug 2025	118	007

Solar Active Regions and flaring

Solar flaring activity was low over the past 24 hours, with only C-class flares identified. A total of 4 numbered sunspot groups were identified on the disk over the past 24 hours, having all Alpha or Beta magnetic configuration. The largest flare was a C2.9 flare (SIDC Flare 5179) peaking on August 20 at 09:30UTC, from SIDC Sunspot Group 607 currently located at N10E90 (Alpha magnetic configuration). Solar flaring activity is expected to be low over the next 24 hours, with C-class flares likely and a small chance for M-class flares.

Coronal mass ejections

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

Solar wind

Fast solar wind conditions were recorded over the past 24 hours, following the arrival of the High Speed Stream associated with SIDC Coronal Hole 116. The speed increase to mainly 620 km/s with a peak at 688 km/s. The interplanetary magnetic field gradually decreased from 20 nT to 4nT, with the Bz reaching a minimum value of -11 nT. The solar wind speed is expected to remain fast in the next 24 hours.

Geomagnetism

Over the past 24 hours, the geomagnetic activity was mainly active, with a isolated period of minor storm, both globally and locally, due to the arrival of the high speed stream. Active geomagnetic conditions are expected in the next 24 hours.

Proton flux levels

The greater than 10 MeV proton flux remained below the 10 pfu threshold and is expected to remain so over the next days.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux remained below the 1000 pfu alert threshold, and is expected to remain below the threshold during the next 24 hours. The 24h electron fluence was at normal levels and is expected to remain so.

Today's estimated international sunspot number (ISN): 056, based on 15 stations.

Solar indices for 19 Aug 2025

Wolf number Catania	///
10cm solar flux	116
AK Chambon La Forêt	032
AK Wingst	019
Estimated Ap	024
Estimated international sunspot number	037 - Based on 22 stations

Noticeable events summary

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

All times in UTC

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