A halo or partial-halo CME was detected with the following characteristics: t0 | dt0| pa | da | v | dv | minv| maxv| 2023-05-23T10:24:22.895 | 2.0 | 124 | 150 | 473 | 263 | 205 | 1116 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

There are ten visible active regions on the solar disk. The newly numbered NOAA AR 3223 (recently rotated into view over the east limb) is the one producing most of the flaring activity, including the largest flare of the past 24 hours: M4.3 peaking at 22:52 UTC on 31 May. NOAA AR 3315 and 3319 are also contributing to the flaring activity. More M-class flares can be expected and X-class flares are possible. No Earth-directed coronal mass ejections (CMEs) were detected in the past 24 hours. A positive polarity coronal hole in the southern hemisphere crossed the central meridian on 29 May. A related high speed solar wind stream may arrive to the Earth in the next 24 hours. Over the past 24 hours the greater than 10 MeV GOES proton flux was at nominal levels and is expected to remain so in the next 24 hours. The greater than 2 MeV electron flux was below the 1000 pfu threshold over the past 24 hours and is expected to remain so in the next 24 hours. The 24h electron fluence was at normal levels and is expected to remain at normal levels over the next 24 hours.

The geomagnetic conditions over the past 24 hours reached active levels (K_Belgium and Kp up to 4). More active to minor storm periods can be expected for the next 24 hours. The Earth is inside slow solar wind, but the solar wind speed has started to increase (currently at 450 km/s) with an interplanetary magnetic field around 7 nT. In the next 24 hours we will most likely see the arrival of the high speed stream emanating from a positive polarity coronal hole in the southern hemisphere (it is located at 20 degrees south in latitude, so we don’t expect a strong effect of the fast solar wind).