Solar activity forecast for the period September 15 - September 21, 2017


Activity level: very low to low
X-ray background flux (1.0-8.0 A): in the range A3.0-B2.0
Radio flux (10.7 cm): a fluctuation in the range 69-85 f.u.
Events: class C (0-6/period), class M (0-1/period), class X (0/period), proton (0-1/period)
Relative sunspot number (Ri): in the range 11-70

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


Geomagnetic activity forecast for the period September 14 - September 21, 2017


Quiet: Sep 18 - 19, 21
Unsettled: Sep 17 - 21
Active:    Sep 14 - 16
Minor storm: Sep 14 - 15
Major storm: 0
Severe storm: 0

Geomagnetic activity summary:
Because of two CMEs last week, we expect active (with possible minor storm
event) conditions in the next three days. We expect these conditions to
September 16, then, we expect geomagnetic activity decrease to unsettled
level.
An isolated active episode is also possible about September 20. Then, we
expect quiet to unsettled conditions return.

Tomas Bayer
RWC Prague
Institute of Geophysics of the ASCR, Prague
Department of Geomagnetism
Budkov observatory (BDV)


Geomagnetic activity forecast for the period September 15 - October 11, 2017


Geomagnetic field will be: 
quiet on September 23 - 24 
mostly quiet on September 20, 27 
quiet to unsettled September 19, 21 - 22, October 4, 6 
quiet to active on September 15, 17, 25 - 26, 30, October 1 - 3, 7 - 8, 10 - 11  
active to disturbed on September 16, 18, 28 - 29, October 5, 9 
 
Amplifications of the solar wind from coronal holes are expected 
on September 15 - 19, 27 - 29, October (1,) 2 - 5, (8)

Remark:
- Parenthesis means lower probability of activity enhancement 
and/or lower reliability of prediction. 

F. K. Janda, OK1HH 
Czech Propagation Interested Group 
OK1HH compiling weekly forecasts since January 1978 
e-mail: ok1hh(at)rsys.cz