Issued: 2026 May 21 17:00 UTC


Analysis from May 20/1700 UTC to May 21/1700 UTC:

Sunspot Regions on the Disk 21/1623 UTC (SDO Continuum): 5
The Largest Event: C5.6 from region 4436 at 21/1321 UT
X-ray background flux (1.0-8.0 A) May 20: B6.3
Radio Flux 10.7 cm at 20/2300 UTC (Penticton): 111
Solar Wind Speed at 21/1645 UTC: 430.4 km/s, density : 1.9 p/cm^3


Forecast:

Activity level will be: low - explanation
Event probabilities: Class C: 80%, Class M: 25%, Class X: 05%, Proton: 05%
X-ray background flux (1.0-8.0 A): in the range B6.5 - B7.2
Radio Flux 10.7 cm: a fluctuation in the range 115-120

Martina Pavelková
RWC Prague, Astronomical Institute, Solar Dept., Ondrejov, Czech Republic
e-mail: sunwatch(at)asu.cas.cz