Viewing archive of Saturday, 28 June 2025

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2025 Jun 28 1244 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
28 Jun 2025	117	013
29 Jun 2025	117	013
30 Jun 2025	115	011

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 C1.2 flare (SIDC Flare 4769) peaking on June 27 at 13:33 UTC, which was produced by SIDC Sunspot Group 530 (NOAA Active Region 4120). During the flare, the source region (AR 4120) of the flare had beta-gamma 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 narrow coronal mass ejection (CME) was observed in SOHO/LASCO-C2 images around 11:48 UTC on Jun 27 (as detected by CACTUS tool). It was associated with a filament eruption on NW quadrant of the Sun, which was part of an extended filament in the northern hemisphere. This CME is not expected to arrive at Earth. No other Earth-directed CMEs were detected in the available coronagraph observations during last 24 hour.

Solar wind

Earth is still inside a fast solar wind stream, with the continuous arrival of high speed streams (HSSs) from the large SIDC Coronal Hole 116 (negative polarity) which crossed the central meridian during Jun 21-25. The solar wind speed ranged from 575 km/s to 775 km/s. The interplanetary magnetic field ranged between 1 nT and 5 nT, and the North- South component (Bz) ranged between -4 nT and 4 nT. In the next 24 hours, enhanced solar wind conditions are expected to continue until Jun 28 with the further arrival of HSSs from the same coronal hole.

Geomagnetism

Geomagnetic conditions were at quiet to unsettled conditions (NOAA Kp 2 to 3), both globally and locally during the past 24 hours. In the next 24 hours, quiet to active conditions (K 1 to 4) are possible with the continuous arrival of HSSs from the same coronal hole.

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 for the next 24 hours.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux, as measured by GOES-19 and GOES-18 satellites, exceeded the 1000 pfu alert threshold level for most of the time 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 currently above the threshold level and it is expected to remain so during most of 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): 132, based on 21 stations.

Solar indices for 27 Jun 2025

Wolf number Catania	114
10cm solar flux	118
AK Chambon La Forêt	020
AK Wingst	024
Estimated Ap	023
Estimated international sunspot number	118 - Based on 27 stations

Noticeable events summary

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

All times in UTC

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