A full halo CME was first seen at 05:36 UT on LASCO C2, originating from an eruption close to NOAA AR 3683 (located at the southwest, at S25W60), associated with a C6.7 flare. The CME is fast, early speed estimates are around 1500 km/s, but more images are needed for a better estimation. The bulk of the CME is directed to the southwest, but a glancing blow can be expected on 22 May. Due to the location of the event and the speed of the CME, a proton event may occur in the coming hours.

A halo or partial-halo CME was detected with the following characteristics: t0 | dt0| pa | da | v | dv | minv| maxv| 2024-05-20T05:36:07.525 | 1.0 | 239 | 180 | 1564 | 235 | 1079 | 1956 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 nine visible ARs on the solar disk. There were three M-class flares in the last 24 hours, from NOAA 3679 (beta-gamma magnetic field configuration) and 3683 (beta magnetic field configuration. The strongest one was an M2.3 peaking at 04:04 UTC from NOAA AR 3683. NOAA AR 3685 (beta gamma magnetic field configuration) has grown in size and has also potential for strong flares. More M-class flares can be expected, and X-class flares are possible, in the next 24 hours. No Earth directed CME has been observed in the last 24 hours. A negative polarity coronal hole in the northern hemisphere has developed a low latitudinal extension that traversed the central meridian on 21 May. A possible arrival of high speed steam from this coronal hole could arrive at the Earth on 24 May. The 10 MeV GOES-18 proton flux was below threshold in the past 24 hours. Since the regions producing the M-class flaring are close to the west limb, a proton event cannot be discarded in the next 24 hours The greater than 2 MeV electron flux from GOES 16 was below the threshold level in the last 24 hours. It is expected to remain below the threshold during the next 24 hours. The electron fluence was at normal levels for the last 24 hours and is expected to remain so.

Geomagnetic conditions have been quiet in the last 24 hours (Kp and K_BEL up to 2). Similar quiet conditions can be expected for the next 24 hours. The solar wind at the Earth is slow, with speeds around 360 km/s and interplanetary magnetic field around 6 nT. Similar conditions can be expected for the next 24 hours.