Solar activity forecast for the period September 22 - September 28, 2017


Activity level: very low to moderate
X-ray background flux (1.0-8.0 A): in the range A4.0-B7.0
Radio flux (10.7 cm): a fluctuation in the range 69-90 f.u.
Events: class C (0-12/period), class M (0-4/period), class X (0/period), proton (0-1/period)
Relative sunspot number (Ri): in the range 11-100

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 21 - September 28, 2017


Quiet: Sep 22 - 23, 26
Unsettled: Sep 21 - 23, 25 - 27
Active:    Sep 24 - 25, 28 - 29
Minor storm: Sep 28
Major storm: 0
Severe storm: 0

Geomagnetic activity summary:
The nearest two days, after the last active episode, we expect geomagnetic
activity decrease to quiet to unsettled level. Further, the next active
episode is expected about Sunday, September 24. Then, we expect quiet to
unsettled conditions return to September 27. The last days of the
forecasted period, we expect one active episode more which can read minor
storm effect.

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



Geomagnetic activity forecast for the period September 22 - October 18, 2017


Geomagnetic field will be: 
quiet on September 22, 24 
mostly quiet on September 23, 26, October 18 
quiet to unsettled September 25, October 5 - 6 
quiet to active on September 27, 30, October 1 - 4, 7 - 8, 10 - 11, 14 - 17  
active to disturbed on September 28 - 29, October 9, 12 - 13  
 
Amplifications of the solar wind from coronal holes are expected 
on September 27 - 29, October (1,) 2 - 5, (8, 11 - 12,) 13 - 15, (16 - 17)

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