giovedì 20 aprile 2017

Weekly Forecasts Bulletin

Solar activity forecast for the period April 21 - April 27, 2017


Activity level: mostly very low to low
X-ray background flux (1.0-8.0 A): in the range A5.0-B3.0
Radio flux (10.7 cm): a fluctuation in the range 60-105 f.u.
Events: class C (0-5/day), class M (0-3/period), class X (0/period), proton (0/period)
Relative sunspot number (Ri): in the range 11-95

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

Geomagnetic activity forecast for the period April 21 - April 27, 2017


Quiet: Apr 21 - 22
Unsettled: Apr 22 - 23, 25 - 27
Active:   Apr 23 - 25
Minor storm: possible Apr 23 - 24
Major storm: 0
Severe storm: 0

Geomagnetic activity summary:
Till the nearest Saturday, April 22, we expect quiet to unsettled conditions.
Between Sunday, April 23, and Monday, April 24, we expect active episode
arrival caused by present equatorial coronal hole. During these two days,
storming effect is possible.
The following days, we expect at most unsettled conditions only with
isolated active episodes. The last day of the forecasted period, we expect
geomagnetic activity decrease to quiet to unsettled level.

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

Geomagnetic activity forecast for the period April 21 - May 17, 2017


Geomagnetic field will be:
quiet on April 22, 30, May 13
mostly quiet on April 29, May 8
quiet to unsettled April 21, May 3, 7, 10 - 12, 14 - 15
quiet to active on April 24 - 25, 27 - 28, May 1 - 2, 4 - 5, 8, 16
active to disturbed on April 23, 26, May 6, 17

Amplifications of the solar wind from coronal holes are expected
on April (21 - 22,) 23 - 28, May (1 - 4,) 7 - 8, (9 - 11,) 18 - 19

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 1978
e-mail: ok1hh(at)rsys.cz