Viewing archive of Sunday, 15 June 2025

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2025 Jun 15 1236 UTC

SIDC Forecast

Solar flares

M-class flares expected (probability >=50%)

Geomagnetism

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

Solar protons

Quiet

	10cm flux	Ap
15 Jun 2025	151	014
16 Jun 2025	151	018
17 Jun 2025	151	011

Solar Active Regions and flaring

Solar flaring activity was moderate over the past 24 hours, with four M-class flares identified. A total of seven numbered sunspot groups were observed on the visible solar disk during this period. SIDC Sunspot Group 513 (NOAA Active Region 4105) produced all four M-class flares. The largest event was an M6.8 flare (SIDC Flare 4639) that peaked on June 14 at 23:01 UTC. This region was also responsible for an M2.2 flare (SIDC Flare 4647) peaking on June 15 at 07:56 UTC, an M1.9 flare (SIDC Flare 4646) peaking on June 15 at 10:47 UTC, and an M1.0 flare (SIDC Flare 4637) peaking on June 14 at 18:04 UTC. Other numbered sunspot groups also contributed to flaring activity, in particular SIDC Sunspot Group 523 (NOAA Active Region 4114), which is currently located at N18E22, has a Beta-Gamma-Delta magnetic configuration, and continued to grow over the past 24 hours. Solar flaring activity is expected to remain moderate over the next 24 hours, with M-class flares likely and a small chance for X-class flares.

Coronal mass ejections

A coronal mass ejection was visible in LASCO/C2 imagery starting at 08:36 UTC on June 15. This CME appears potentially fast and followed the M2.2 flare (SIDC Flare 4647), which peaked at 07:56 UTC and was produced by SIDC Sunspot Group 513 (NOAA Active Region 4105). The eruption seems to have generated a large coronal wave visible in SDO/AIA imagery. This CME is currently under analysis as it may result in a glancing blow to Earth. No other clear Earth-directed coronal mass ejections were identified in the available data.

Coronal holes

The large SIDC Coronal Hole 104 (mid-latitude south coronal hole with a negative polarity) is currently transiting the central meridian. It is a recurrent coronal that first reached the central meridian on June 08.

Solar wind

Solar wind conditions were moderately disturbed over the past 24 hours. The solar wind speed gradually increased, ranging from about 475 km/s to peaks near 573 km/s. This enhancement in solar wind speed is consistent with the arrival of a new high-speed stream associated with SIfrom DC Coronal Hole 104 (a mid-latitude southern coronal hole with positive polarity that crossed the central meridian on June 12). The total interplanetary magnetic field (Bt) was moderately elevated, fluctuating between 5 nT and peaks near 8 nT. The southward component (Bz) varied throughout the period, occasionally reaching minima near -6 nT, but without prolonged southward intervals. The phi angle was predominantly in the positive sector, supporting the connection to the high-speed stream from SIDC Coronal Hole 104. As the coronal hole is very large in longitude, we anticipate that the conditions will remain moderately disturbed over the next few days as the high-speed stream (HSS) continues to affect Earth before gradually diminishing as it moves away.

Geomagnetism

Geomagnetic conditions were mostly quiet to unsettled during the reporting period. The NOAA Kp index stayed within the quiet to unsettled range, and local K_BEL values reflected similar conditions. Geomagnetic activity is expected to remain generally unsettled over the next 24 hours, although isolated active periods are possible as the influence of the high-speed stream from SIDC Coronal Hole 104 persists.

Proton flux levels

The greater-than-10 MeV proton flux, as measured by GOES-18, remained at background levels over the past 24 hours and is expected to stay at background 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-18 and GOES-19 satellite remained below the 1000 pfu alert threshold over the past 24 hours. 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): 147, based on 15 stations.

Solar indices for 14 Jun 2025

Wolf number Catania	///
10cm solar flux	151
AK Chambon La Forêt	020
AK Wingst	026
Estimated Ap	026
Estimated international sunspot number	148 - Based on 26 stations

Noticeable events summary

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

All times in UTC

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