Viewing archive of Sunday, 29 June 2025

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2025 Jun 29 1243 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
29 Jun 2025	123	010
30 Jun 2025	122	011
01 Jul 2025	121	029

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 C4.0 flare (SIDC Flare 4771) peaking on June 28 at 19:54 UTC, which was produced by SIDC Sunspot Group 537 (NOAA Active Region 4126). During the flare, the source region (AR 4126) of the flare had beta configuration of its photospheric magnetic field. A total of 10 numbered sunspot groups were identified on the disk over the past 24 hours. The solar flaring activity is expected to be at low to moderate levels over the next 24 hours with C-class flares expected, M-class flares probable, and a small chance of X-class flares.

Coronal mass ejections

A partial halo coronal mass ejection (CME) was first observed in SOHO/LASCO-C2 images around 21:00 UTC on Jun 28. It was associated with the C4.0 flare (peaked at 19:54 UTC on June 28) produced by SIDC Sunspot Group 537 (NOAA Active Region 4126). With its source region (N06 W21) closer to the central meridian, the corresponding ICME is expected to impact the Earth on Jul 01-02. No other Earth-directed CMEs were detected in the available coronagraph observations during last 24 hour.

Coronal holes

Recurrent negative polarity coronal hole (SIDC Coronal Hole 111) which spans from 20 to 40 S has started to cross the central meridian. The high speed streams originating from this coronal hole are expected to impact the Earth on Jul 02.

Solar wind

Over the past 24 hours, the solar wind parameters remained under the influence of high speed streams (HSSs) from the SIDC Coronal Hole 116 (negative polarity) which crossed the central meridian during Jun 21-25. The solar wind speed ranged between 495 km/s and 700 km/s. The North-South component (Bz) ranged between -4 and 5 nT. The interplanetary magnetic field ranged between 3 nT to 6 nT. In the next 24 hours, we expect a gradual transition from fast to slow solar wind.

Geomagnetism

Geomagnetic conditions were globally at quiet (NOAA Kp 1 to 2) and locally at quiet to unsettled conditions (K_BEL 1 to 3). We expect quiet to unsettled conditions (K 1 to 3) in the next 24 hours.

Proton flux levels

The greater than 10 MeV GOES proton flux was below the threshold level over the past 24 hours and it is expected to remain so unless there is any major flare from the active regions near the W limb.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux, as measured by GOES-19 and GOES-18 satellites, remained above the 1000 pfu alert threshold level during the past 24 hours, in response to the high solar wind speed associated with the SIDC Coronal Hole 116 crossing the central meridian during Jun 21-25. The electron flux is expected to remain so during the next 24 hours. The 24h electron fluence was at moderate levels and is expected to remain so.

Today's estimated international sunspot number (ISN): 149, based on 25 stations.

Solar indices for 28 Jun 2025

Wolf number Catania	///
10cm solar flux	122
AK Chambon La Forêt	014
AK Wingst	011
Estimated Ap	011
Estimated international sunspot number	127 - Based on 31 stations

Noticeable events summary

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

All times in UTC

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