Dear Collaborators,

Solar activity is at a moderate level. Target region NOAA 13639 was stable in terms of spot area and number of spots since the last message, remaining classified as a beta-gamma-delta/E-type sunspot group. This region has decreased significantly in both flaring frequency and peak flaring magnitude, producing only a C4.3 flare in the period (17-Apr-2024 at 20:51 UT). In contrast, newly numbered NOAA 13645 produced ten C-class and two M-class flares (M1.6 on 17-Apr-2024 at 21:55 UT and M1.3 on 18-Apr-2024 at 07:17 UT). This region was classified as a beta-gamma/C-type sunspot group at the start of the UT day, but now appears to be a D-type group with a potential delta spot. The largest flare in the period was an M2.2 on 18-Apr-2024 at 02:32 UT from NOAA 13638 (a beta/C-type group) that is located close to NOAA 13645 (and also NOAA 13637). The MM#003 Major Flare Watch continues, but the target switches to NOAA 13645. Additional low M-class flares are expected over the following 24-hour period, with a good chance for a >M5 flare.

The position of NOAA 13645 on 18-Apr-2024 at 12:30 UT is:

S10E17 , ( -278", -82" )

See http://www.SolarMonitor.org for images and http://solar.physics.montana.edu/max_millennium/ops/observing.shtml for a description of the current Max Millennium Observing Plan.

Regards,

Shaun Bloomfield (Northumbria University)