Solar activity forecast for the period September 17 - September 18, 2026

Issued: 2026 September 16 17:00 UTC


Analysis from September 15/1700 UTC to September 16/1700 UTC:

Sunspot Regions on the Disk 16/1300 UTC (SDO Continuum): 4
The Largest Event: B3.9 from Region N07E67 at 16/1102 UT
X-ray background flux (1.0-8.0 A) September 15: B2.5
Radio Flux 10.7 cm at 15/2300 UTC (Penticton): 103
Solar Wind Speed at 16/1645 UTC: 476 km/s, Density: 0.1 p/cm^3


Forecast:

activity level will be very low
Event probabilities: Class C: 40, Class M: 05, Class X: 01, Proton: 01
X-ray background flux (1.0-8.0 A): in the range B2.0-B3.0
Radio Flux 10.7 cm: a fluctuation in the range 91-115

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