Weekly forecast

Solar activity forecast for the period June 12 - June 18, 2026

Activity level: low to moderate
X-ray background flux (1.0-8.0 A): in the range B6.5-C2.5
Radio flux (10.7 cm): a fluctuation in the range: 106-198
Events: class C (1-8/day), class M (0-2/period), class X (0-0/period), proton (0-1/period)
Relative sunspot number (Ri): in the range 62-158

Vlastislav Feik
RWC Prague, Astronomical Institute, Solar Dept., Ondrejov, Czech Republic 

Geomagnetic activity forecast for the period June 12 - June 18, 2026

Quiet:   Jun 15 - 18
Unsettled: Jun 13 - 15
Active:  Jun 12 - 13
Minor storm:  possible about  Jun  12
Major storm:  0
Severe storm: 0

We expect an active episode within the two coming days when we expect geomagnetic activity enhancement beacuse of concurrent effect of actual coraonal hole and the last CME's. Nevertheless, we expect the activity at the range of unsettled and active level with possible minor storm event.
Since Sunday, June 14, we expect a partial decrease to unsettled level, generally.
The last part of week,since June 15, 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)

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere June 12 - June 18, 2026

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere, June 11, 2026

Overall solar activity is rather low, while is expected to continue declining through mid-June. Most active regions are relatively small, typically with a simple magnetic configuration. Nevertheless, class C flares are occasionally observed, sometimes accompanied by CMEs.

Currently, CMEs from June 9 and 11 are expected to arrive, leading to an increase in geomagnetic activity from June 12 to 14. A period of several days of calm activity is predicted to begin on June 16.

Shortwave propagation has begun to be significantly affected by the sporadic E layer, while its increased activity can be expected to continue over the next few days.

F. K. Janda, A.R.S. OK1HH
http://ok1hh.nagano.cz/
Emails: ok1hh(at)crk.cz, ok1hh(at)rsys.cz
Pmail: OK1HH(at)OK0NAG.#BOH.CZE.EU

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