Daily bulletin on solar and geomagnetic activity from the SIDC

Emesso: 2026 May 11 1231 UTC

SIDC Forecast

Brillamenti solari

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

Geomagnetism

Quiet (A<20 and K<4)

Protoni solari

Quiet

	10cm flux	Ap
11 May 2026	128	003
12 May 2026	130	009
13 May 2026	130	029

Solar Active Regions and flaring

Solar flaring activity was high over the past 24 hours, with one M-class flare. The strongest flare was an M5.7 flare (SIDC Flare 7671), peaking at 13:39 UTC on May 10, which was associated with the returning SIDC Sunspot Group 825 (NOAA Active Region 4436, magnetic type beta), located in the northeast quadrant. There are currently five numbered active regions on the solar disk. SIDC Sunspot Group 860 (NOAA Active Region 4432) is the most complex group with magnetic type beta-gamma. The solar flaring activity is expected to be moderate over the next 24 hours, with M-class flares likely and a small chance for X-class flares.

Espulsioni di massa coronale

A partial halo Coronal Mass Ejection (SIDC CME 650) was observed in LASCO/C2 and C3 coronagraph imagery starting from around 13:48 UTC on May 10. The CME is associated with the M5.7 flare (SIDC Flare 7671) peaking at 13:39 UTC on May 10. Preliminary analysis suggests that the bulk of the CME has a fitted speed around 1300 km/s. While the bulk of the ejecta appears to be directed eastward, a glancing blow at Earth from early UTC on May 13 cannot be excluded. Further analysis is ongoing. No other Earth-directed CMEs were observed in the available coronagraph imagery.

Vento solare

Over the past 24 hours, the solar wind parameters (ACE) reflected mostly slow solar wind conditions. Speed values ranged between 360 km/s and 440 km/s. The interplanetary magnetic field values were between 3 nT and 6 nT. The Bz component varied between -4 nT and 5 nT. The interplanetary magnetic field angle was mostly in the positive sector. Mostly slow solar wind conditions are expected over the next 24 hours, with a small chance for a mild high-speed stream influence from the small mid- latitude positive polarity coronal hole (SIDC Coronal Hole 161), which crossed the central meridian on May 9.

Geomagnetism

Geomagnetic conditions globally and locally were mostly at quiet levels (NOAA Kp 1 to 2, K BEL 1 to 2). Mostly quiet geomagnetic conditions are expected over the next 24 hours, with a small chance for isolated unsettled to active intervals due to a possible mild high-speed stream influence from SIDC Coronal Hole 161.

Proton flux levels

The greater than 10 MeV proton flux was below the 10 pfu threshold level over the past 24 hours. It is expected to remain below the threshold level over the next 24 hours.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux measured by GOES 18 and GOES 19 was below the 1000 pfu threshold in the last 24 hours. The greater than 2 MeV electron flux is expected to be below the 1000 pfu threshold over the next 24 hours. The 24-hour electron fluence is presently at normal levels and is expected to remain so over the next 24 hours.

Today's estimated international sunspot number (ISN): 082, based on 14 stations.

Solar indices for 10 May 2026

Wolf number Catania	///
10cm solar flux	126
AK Chambon La Forêt	010
AK Wingst	005
Estimated Ap	004
Estimated international sunspot number	091 - Based on 27 stations

Noticeable events summary

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