Viewing archive of Thursday, 12 June 2025

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2025 Jun 12 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
12 Jun 2025	140	014
13 Jun 2025	140	013
14 Jun 2025	140	013

Solar Active Regions and flaring

Solar flaring activity was low over the past 24 hours, with multiple C-class flares recorded. A total of nine numbered sunspot groups were observed on the visible solar disk. The largest event was a C8.5 flare (SIDC Flare 4616), which peaked at 19:11 UTC on June 11 and originated from SIDC Sunspot Group 523 (NOAA Active Region 4114), a Beta-type group currently located at N17E60. SIDC Sunspot Group 523 (NOAA Active Region 4114) currently located at N17E60 has a Beta magnetic configuration stands out as the primary flare source, while SIDC Sunspot Group 513 (NOAA Active Region 4105) with a Beta-Gamma magnetic configuration and SIDC Sunspot Group 516 (NOAA Active Region 4107) Beta- Delta magnetic configuration remain of interest due to their magnetic complexity. Given the active configuration of these regions, continued C-class flares are very likely, with a chance of isolated M-class events over the next 24-hours.

Coronal mass ejections

Several narow outflow were observed in the available LASCO/C2 coronagraph imagery over the past 24 hours. However, no clear Earth-directed coronal mass ejections were identified in the data.

Coronal holes

The SIDC Coronal Hole 104 (mid-latitude south coronal hole with a negative polarity) is beginning to cross the central meridian today, on June 12. It is a recurrent coronal that first reached the central meridian on June 08.

Solar wind

Solar wind conditions remained moderately disturbed over the past 24 hours, with solar wind speeds ranging from 405?km/s to peaks near 505?km/s. The total interplanetary magnetic field (Bt) fluctuated between 5?nT and 12?nT. The southward component (Bz) was variable, reaching a minimum of -10.7?nT and remaining negative for prolonged periods. The phi angle remained predominantly in the negative sector. These conditions suggest that Earth is under the influence of a high-speed solar wind stream originating from SIDC Coronal Hole 118, which is an equatorial coronal hole with negative polarity that crossed the central meridian on June 8. Solar wind speeds are expected to increase later today and into tomorrow, while the interplanetary magnetic field is expected to gradually return to nominal levels.

Geomagnetism

Geomagnetic conditions reached active to minor storm levels globally, with NOAA Kp-index values peaking at 5 between 21:00 UTC on June 11 and 06:00 UTC on June 12. Locally in Belgium, K_BEL-index reached 5 between 18:00 UTC and 20:00 UTC on June 11. These disturbed conditions were driven by enhanced solar wind condition with prolonged periods of southward Bz in response to the influence of a high-speed solar wind stream originating from SIDC Coronal Hole 118 (an equatorial coronal hole that crossed the central meridian on June 8). Over the next 24 hours, geomagnetic activity is expected to remain elevated, with intermittent active periods, followed by a return to unsettled to quiet conditions later tomorrow.

Proton flux levels

The greater-than-10 MeV proton flux, as measured by GOES-18, remained at nominal levels over the past 24 hours and is expected to stay at nominal levels throughout the next 24 hours. No solar energetic particle events were detected, and none are currently anticipated.

Electron fluxes at geostationary orbit

The greater-than-2 MeV electron flux, as measured by the GOES-19 satellite, remained below the 1000 pfu alert threshold over the past 24 hours. While the GOES-18 satellite briefly recorded values reaching this threshold. Electron fluxes are expected to stay mostly below the alert threshold during the next 24 hours. The 24-hour electron fluence remained at normal to moderate levels and is anticipated to persist at those levels throughout the next day.

Today's estimated international sunspot number (ISN): 138, based on 23 stations.

Solar indices for 11 Jun 2025

Wolf number Catania	179
10cm solar flux	141
AK Chambon La Forêt	032
AK Wingst	022
Estimated Ap	022
Estimated international sunspot number	146 - 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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