Predikce sluneční a geomagnetické aktivity

Solar activity forecast for the period

July 11 - July 17, 2025

Activity level:	low to moderate
X-ray background flux (1.0-8.0 A):	in the range B4.2-C3.8
Radio flux (10.7 cm):	a fluctuation in the range 98-167
Events:	class C (1-12/day), class M (0-3/period), class X (0-1/period), proton (0-1/period)
Relative sunspot number (Ri):	in the range 39-166

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

Geomagnetic activity forecast for the period

July 11 - July 17, 2025

Quiet:	Jul 11, 16 - 17
Unsettled:	Jul 13 - 15
Active:	Jul 10
Minor storm:	possible about Jul 12, 15
Major storm:	0
Severe storm:	0
Geomagnetic activity summary:	We expect geomagnetic activity enhancement at the start of the coming weekend, it can repeat about Tuesday, July 15. These active events can be accompanied by minor storm events. Between these episodes, we expect at most an 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

July 11 - July 17, 2025

Remarks:

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere July 11 - July 17, 2025
Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere – July 10, 2025

In connection with the occurrence of a large coronal hole in the southeastern part of the solar disk, slightly increased geomagnetic activity can be expected. In the coming days (starting July 13-14), it may reach level G1.

On the above-mentioned days (July 13 to 14, or 1–2 days later), the negative impact on the ionosphere could be intensified by declining solar activity. Further developments cannot be predicted with greater accuracy, but the probability of disturbances will be higher in the last third of July.

F. K. Janda, A.R.S. OK1HH

e-mail: ok1hh(at)crk.cz; ok1hh(at)rsys.cz

Pmail: OK1HH(at)OK0NAG.#BOH.CZE.EU