Viewing archive of Tuesday, 19 August 2025

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2025 Aug 19 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
19 Aug 2025	116	019
20 Aug 2025	116	021
21 Aug 2025	118	012

Solar Active Regions and flaring

Solar flaring activity was moderate over the past 24 hours, with 1 M-class flare identified. A total of 7 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 M1.1 flare (SIDC Flare 5177) peaking on August 19 at 04:39 UTC, which was produced by SIDC Sunspot Group 572 (NOAA Active Region 4188), who has a Alpha magnetic configuration and was growing over the past 24 hours. 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

The solar wind conditions at Earth were mainly slow over the past 24 hours. The speed started to increase slightly from 350km/s to 420 km/s. The interplanetary magnetic field reached a maximum of 16 nT with the Bz reaching a minimum value of -7 nT. The solar wind speed is expected to become enhanced in the next 24 hours, due to the potential arrival of the high-speed stream (HSS) associated with the SIDC coronal hole 116.

Geomagnetism

Geomagnetic activity was quiet to unsettled over the past 24 hours both globally and locally. In response to the expected arrival of high-speed stream, geomagnetic conditions are expected to reach active level 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 measured by GOES 18 and GOES 19 has dropped below the 1000 pfu threshold. Electron flux levels are expected to remain below the 1000 pfu threshold over the next 24 hours. The 24-hour electron fluence returned to normal levels and is expected to remain so over the next 24 hours.

Today's estimated international sunspot number (ISN): 038, based on 19 stations.

Solar indices for 18 Aug 2025

Wolf number Catania	049
10cm solar flux	114
AK Chambon La Forêt	016
AK Wingst	011
Estimated Ap	010
Estimated international sunspot number	057 - Based on 32 stations

Noticeable events summary

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

All times in UTC

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