A halo Coronal Mass Ejection (CME) was detected in SOHO/LASCO-C2 data from 07:24 UTC May 27. This CME has a plane of sky speed of around 800km/s and was predominantly directed to the east. It is associated with the X2.8 flare originating from beyond the east limb, with peak time 07:08 UTC on May 27. Due to the location of the source region, initial modelling suggests that the CME is not expected to impact Earth.

A class X2.9 solar X-ray flare occurred on 2024/05/27 with peak time 07:08UT

A halo or partial-halo CME was detected with the following characteristics: t0 | dt0| pa | da | v | dv | minv| maxv| 2024-05-27T07:24:07.463 | 4.0 | 144 | 360 | 744 | 445 | 200 | 1838 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 seven visible ARs on the solar disk. Solar activity has been high over the last 24 hours. The largest flare of the period was an X2.8 flare, with peak time 07:08 UTC on May 27. This flare originated beyond the south-east limb and is likely associated to a returning active region from the last rotation (NOAA AR 3664). Associated Type II and Type IV radio emissions were observed starting at 06:59 UTC and 07:05 UTC, respectively. Currently, NOAA AR 3691 is the most complex region on disk (beta-gamma-delta magnetic field configuration) and produced C-class flaring. The solar flaring activity is expected to be moderate over the next 24 hours with C-class flares expected, M-class flares likely and a low probability for further X-class flares, particularly from the expected returning active region that is about to rotate onto the disk. No Earth directed Coronal Mass Ejections (CMEs) have been detected in the available coronagraph imagery. The CME related to the X2.8 flare will be analysed when data becomes available, however, due to the location of the flaring region any CME is not likely to have a strong Earth directed component. Over the past 24 hours the greater than 10 MeV GOES proton flux was below the 10pfu threshold. There is a slight chance that the proton flux may increase in response to further strong flares. The greater than 2 MeV electron flux increased slightly but remained below the 1000 pfu threshold as measured by GOES 16. It is expected to remain below this threshold over the next days. The 24-hour electron fluence was at nominal levels. The electron fluence is expected remain at nominal levels over the next day.

Geomagnetic conditions were at quiet to unsettled levels (NOAA Kp 3 and Local K Bel 3). Geomagnetic conditions are expected to be mostly at quiet to unsettled levels on May 27 to May 28, with a chance for active conditions in response to the possible glancing blow from the CME of May 23. The solar wind conditions reflected a slow solar wind regime with speeds around 360 km/s and an interplanetary magnetic field around 7 nT. The Bz component reached a minimum value of -5 nT. The interplanetary magnetic field phi angle was predominantly in the positive sector (directed away from the Sun. Slow solar wind conditions are expected to continue generally on May 27 and 28. Minor enhancements in the solar wind speed and magnetic field may be possible from late on May 27, due to a glancing blow associated with the CME of May 23 but this is low confidence.