Viewing archive of Thursday, 30 April 2026

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2026 Apr 30 1245 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
30 Apr 2026	144	013
01 May 2026	143	018
02 May 2026	142	023

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 C5.1 flare (SIDC Flare 7575) peaking on April 30 at 00:31 UTC, which was produced by SIDC Sunspot Group 851 (NOAA Active Region 4424). During the flare, the source region (SIDC Sunspot Group 851) of the flare had beta configuration of its photospheric magnetic field. 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

No Earth-directed coronal mass ejections (CMEs) were detected in the available coronagraph observations during the last 24 hour.

Solar wind

Earth is presently within the slow solar wind regime, but the speed has increased from 295 km/s to 400 km/s. The North-South component (Bz) ranged between -9 and 7 nT. The interplanetary magnetic field ranged between 1 nT to 11 nT. This is possibly due to the influence of solar wind from the SIDC Coronal Hole 149, which crossed the central meridian during Apr 26-28 (recurrent, negative polarity). In the next 24 hours, enhanced solar wind conditions may be expected with the further arrival of high speed streams from the same coronal hole.

Geomagnetism

Geomagnetic conditions were globally and locally quiet (NOAA Kp 0 to 1 and K BEL 1 to 2). In the next 24 hours, active to minor storm conditions (K 4 to 5) are possible if the high speed streams from the SIDC Coronal Hole 149, which crossed the central meridian during Apr 26-28 (negative polarity), arrives at Earth.

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, 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 moderate level and is expected to remain so in the next 24 hours.

Today's estimated international sunspot number (ISN): 151, based on 22 stations.

Solar indices for 29 Apr 2026

Wolf number Catania	171
10cm solar flux	143
AK Chambon La Forêt	010
AK Wingst	006
Estimated Ap	004
Estimated international sunspot number	135 - Based on 29 stations

Noticeable events summary

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

All times in UTC

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