A partial halo Coronal Mass Ejection (CME) was observed in LASCO/C2 and C3 coronagraph imagery starting from around 13:48 UTC on May 10. The CME is associated with an M5.7 flare with peak time 13:39 UTC on May 10, from SIDC Sunspot Group 866 (NOAA Active Region 4436), located in the northeast quadrant. 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 may arrive at Earth starting from the early UTC hours on May 13. Further analysis is ongoing.

A class M5.7 solar X-ray flare occurred on 2026/05/10 with peak time 13:39UT

A halo or partial-halo CME was detected with the following characteristics: t0 | dt0| pa | da | v | dv | minv| maxv| 2026-05-10T13:48:23.558 | 3.0 | 24 | 162 | 614 | 176 | 218 | 844 t0: onset time, earliest indication of liftoff dt0: duration of liftoff (hours) pa: principal angle, counterclockwise from North (degrees) da: angular width of the CME (degrees), v: median velocity (km/s) dv: variation (1 sigma) of velocity over the width of the CME mindv: lowest velocity detected within the CME maxdv: highest velocity detected within the CME

The solar flaring activity has at low levels over the past 24 hours. A total of 5 numbered sunspot groups were identified on the visible solar disk. Most of the flaring activity was produced by SIDC Sunspot Group 860 (NOAA Active Region 4432), including a C3.7 flare (SIDC Flare 7660) peaking at 09:39 UTC on May 10. This region currently located at N13W46 has exhibited further growth and remains classified as magnetic type beta-gamma. SIDC Sunspot Group 866 (NOAA Active Region 4436) currently located at N18E65 has been re-assessed and appears to be the returning SIDC Sunspot Group 825 (previously NOAA Active Regions 4397/4419). It has produced only isolated low C-class flaring. SIDC Sunspot Group 862 (NOAA Active Region 4433) currently located at S16W16 remains classified as magnetic type beta, but has exhibited further decline. The remaining regions have been magnetically simple and quiet. The solar flaring activity is expected to reach moderate levels over the next 24 hours with likely isolated M-class flaring. No other Earth-directed coronal mass ejection (CMEs) have been identified in the available coronagraph imagery over the past 24 hours. A mid-latitude positive polarity coronal hole (SIDC Coronal Hole 159) is currently residing on the central meridian. The high-speed stream related to it might arrive at Earth on May 13, possibly mixed with any mild high-speed stream influence related to SIDC Coronal Hole 161, which has some chances of arrival on May 12. Over the past 24 hours the greater than 10 MeV GOES proton flux was at nominal levels and is expected to remain so over the 24 hours over the next 24 hours. The greater than 2 MeV electron flux as measured by GOES 18 and GOES 19 was below the 1000 pfu threshold over the past 24 hours and is expected to remain so over the next days. The 24-hour electron fluence was at nominal levels and is expected to remain so over the next days.

The geomagnetic conditions over the past 24 hours have been quiet. Predominantly quiet conditions are expected for the next days with small chances of active to minor storm conditions to be reached late UTC on May 12, pending a possible mild high-speed stream arrival associated with SIDC Coronal Hole 161. Over the past 24 hours the solar wind parameters (as measured by ACE at L1) exhibited a slow return towards nominal slow solar wind conditions. The interplanetary magnetic field (B) was weak with a maximum value of 4.6 nT and a minimum Bz (north-south) component of -3 nT. The solar wind speed was on a declining trend varying in the range of 384 to 540 km/s. The B field phi angle was predominantly in the positive sector (directed away from the Sun). The solar wind parameters are expected to be at background slow solar wind conditions over the next days with some probability for a mild high-speed stream arrival related to SIDC Coronal Hole 161 late UTC on May 12.