Viewing archive of Sunday, 1 June 2025

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2025 Jun 01 1241 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Major (ISES: Severe) magstorm expected (A>=100 or K>=7)

Solar protons

Proton event in progress (>10 MeV)

	10cm flux	Ap
01 Jun 2025	167	130
02 Jun 2025	170	082
03 Jun 2025	173	037

Solar Active Regions and flaring

Solar flaring activity was moderate over the past 24 hours with 1 M-class flare recorded. The largest flare was an M2.9 flare (SIDC Flare 4514) peaking on May 31 at 15:49 UTC, which was produced by SIDC Sunspot Group 469 (NOAA Active Region 4100, magnetic type Beta-Gamma-Delta) and was associated with a Type IV radio burst. This region was responsible for most of the flaring activity. SIDC Sunspot group 508 (NOAA Active region 4099, magnetic type Beta) also produced multiple low-level C-class flares. SIDC sunspot group 491(NOAA Active region 4092) has rotated over the west limb and there are currently 6 numbered sunspot groups on the solar disk. The rest of these regions were mostly quiet. The solar flaring activity is expected to be moderate over the next 24 hours, with M-class flares expected and a chance for X-class flares.

Coronal mass ejections

A dimming was observed on disk after the M2.9 flare (SIDC Flare 4514) associated with SIDC Sunspot Group 469 (NOAA Active Region 4100) however, no clear associated Coronal Mass Ejection (CME) is visible. No other Earth directed CMEs were observed in the available coronagraph imagery.

Coronal holes

An extended equatorial coronal hole connecting to the northern polar coronal hole (combined SIDC Coronal Hole 116 and 112) continues to transit the central meridian since May 26. The northern polar extension of the coronal hole is now passing the central meridian.

Solar wind

The solar wind parameters showed the arrival of an ICME associated with the halo coronal CME first detected in SOHO/LASCO-C2 images from early on May 31. A strong shock was registered by DSCOVR at 05:27UTC on June 01, when the solar wind speed jumped from 770 km/s to 980 km/s. The total interplanetary magnetic field values increased from 6nT to 26nT and Bz reached -24nT. The solar wind speed continued to gradually increase and since 08:00 UTC and has been stable around 1000 km/s. At the end of the period, the total interplanetary magnetic field also remains elevated around 20 nT. The solar wind speed and magnetic field are expected to remain extremely high over the next 24 hours, due to the ongoing ICME passage.

Geomagnetism

Geomagnetic conditions reached severe storm levels globally (Kp 8), between 06:00 and 09:00 UTC on June 01, due to the ICME arrival of the CME from early on May 31. Locally, moderate storm conditions were observed (K Bel 6). Further periods of major to severe storm conditions (Kp 8 and Kp 7) are expected over the next 24 hours, due to the expected ongoing ICME passage.

Proton flux levels

The greater than 10 MeV continued to increase and crossed 10 pfu threshold from 17:10 UTC May 31. A further increase was recorded from 05:30 UTC June 01, when the proton flux also crossed the 100 pfu threshold, likely associated with the ICME shock arrival. The proton flux reached a maximum of 666 pfu at 09:10 UTC June 01. The proton flux is expected to remain elevated and above the 10 pfu threshold over the next 24 hours

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux measured by GOES 18 and 19 was above the 1000 pfu threshold for most of the period reducing below it from 06:10 UTC on June 01. The greater than 2 MeV electron flux is expected to remain below the 1000 pfu threshold over the next 24 hours due to the ICME arrival. The 24-hour electron fluence was at moderate to high levels and is expected to be at normal levels over the next 24 hours.

Today's estimated international sunspot number (ISN): 124, based on 15 stations.

Solar indices for 31 May 2025

Wolf number Catania	///
10cm solar flux	164
AK Chambon La Forêt	034
AK Wingst	///
Estimated Ap	019
Estimated international sunspot number	115 - Based on 30 stations

Noticeable events summary

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

All times in UTC

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