Issued: 2026 September 17 17:00 UTC


Analysis from September 16/1700 UTC to September 17/1700 UTC:

Sunspot Regions on the Disk 17/1315 UTC (SDO Continuum): 2
The Largest Event: B7.9 from region N11E50 at 16/2216 UT
X-ray background flux (1.0-8.0 A) September 16: B2.7
Radio Flux 10.7 cm at 16/2300 UTC (Penticton): 100
Solar Wind Speed at 17/1643 UTC: 461.9 km/s, density : 0.6 p/cm^3


Forecast:

Activity level will be: very low to low - explanation
Event probabilities: Class C: 55%, Class M: 05%, Class X: 01%, Proton: 01%
X-ray background flux (1.0-8.0 A): in the range B3.6 - B8.2
Radio Flux 10.7 cm: a fluctuation in the range 90-113

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