Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2026 May 01 1257 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Minor storm expected (A>=30 or K=5)

Solar protons

Quiet

	10cm flux	Ap
01 May 2026	149	007
02 May 2026	147	031
03 May 2026	145	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 C1.9 flare (SIDC Flare 7577) peaking on May 01 at 09:33 UTC, which was produced by SIDC Sunspot Group 847 (NOAA Active Region 4420). A total of 10 numbered sunspot groups were identified on the disk over the past 24 hours. SIDC Sunspot Group 847 (NOAA Active Region 4420) is the most complex group with its beta-gamma-delta magnetic configuration, but it has produced only C-class flares in the past 24 hours. Solar flaring activity is expected to be low to moderate over the next 24 hours, with few C-class flares, possibly M-class flares and a low chance for X-class flares.

Coronal mass ejections

Two subsequent coronal mass ejections (CMEs) were observed in the SOHOS/LASCO C2 field of view around 12:30 UTC and 18:30 UTC on Apr 30 in S-SW. They are faint, wide, and slow CMEs which are observed in STEREO-A/COR2 images too. Further analysis is going-on to investigate the potential Earth-directed components. No other Earth-directed CMEs were detected in the available coronagraph observations during the last 24 hour.

Solar wind

Over the past 24 hours, the solar wind parameters were disturbed under the influence of high speed streams (HSSs) from the negative polarity, recurrent coronal hole (SIDC Coronal Hole 149) which crossed the central meridian during Apr 26-28. The solar wind speed ranged between 350 km/s and 560 km/s. The North-South component (Bz) ranged between -12 and 11 nT. The interplanetary magnetic field ranged from 2 nT to 14 nT. In the next 24 hours, enhanced solar wind conditions are expected to continue with the further arrival of HSSs from the same coronal hole.

Geomagnetism

Geomagnetic conditions were globally at quiet to minor storm levels (NOAA Kp 2 to 5), and locally at unsettled to active conditions (K_BEL 3 to 4) during the past 24 hours. This is possibly due to the arrival of high speed streams (HSSs) from the negative polarity, recurrent coronal hole (SIDC Coronal Hole 149) which crossed the central meridian during Apr 26-28. Active to minor storm conditions (k 4 to 5) are possible in the next 24 hours with the further 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

Electron fluxes at GEO: The greater than 2 MeV electron flux, as measured by GOES-19 and GOES-18 satellites, remained below the threshold level over the past 24 hours and is expected to remain so in the coming 24 hours. The 24h electron fluence is presently at normal level and is expected to be at normal to moderate in the next 24 hours.

Today's estimated international sunspot number (ISN): 157, based on 14 stations.

Solar indices for 30 Apr 2026

Wolf number Catania	203
10cm solar flux	143
AK Chambon La Forêt	032
AK Wingst	017
Estimated Ap	016
Estimated international sunspot number	135 - Based on 38 stations

Noticeable events summary

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