Weekly forecast

Solar activity forecast for the period July 04 - July 10, 2025

Activity level: low to moderate
X-ray background flux (1.0-8.0 A): in the range B4.0-C5.0
Radio flux (10.7 cm): a fluctuation in the range 95-170
Events: class C (1-13/day), class M (0-3/period), class X (0-1/period), proton (0-1/period)
Relative sunspot number (Ri): in the range 43-176	

Karolina Knesplova
RWC Prague, Astronomical Institute, Solar Dept., Ondrejov, Czech Republic

Geomagnetic activity forecast for the period July 04 - July 10, 2025

Quiet: Jul 5 - 8
Unsettled: Jul 4 - 6, 9
Active: Jul 10
Minor storm: possible about Jul 10
Major storm:  unlikely about Jul 10
Severe storm: 0

Since Saturday, July 5, we expect partial geomagnetic activity decrease to quiet to unsettled level.
At the end of currently forecasted period, an active episode with potential storming event is possible.  But, till the Wednesday, July 10, we expect quiet to unsettled conditions, generally.

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 July 04 - July 10, 2025

Although solar activity is lower this year than it was last year, it is still at the maximum level of the eleven-year cycle. Moreover, it is quite possible that it will increase further this year. This is indicated by the continuing slight predominance of activity in the northern half of the solar disk, while in the southern half we more often observe relatively large coronal holes. The active regions are mostly simple (magnetic type alpha or beta) and therefore, with a few exceptions, do not show significant eruptive activity.

Although solar flares have not been powerful recently, they are quite often accompanied by CMEs. When ejected particles hit Earth, it is often three to four days after the CME is observed, instead of the usual two to three days. This is one reason why the error in predicting the arrival time of the particle cloud is slightly increasing. This is especially true when their source is on the far side of the Sun.

The solar wind has finally slowed down in recent days (from speeds of over 800 km/s observed not long ago to less than 400 km/s now) and the interstellar magnetic field has weakened, which has finally had a positive effect on the state of the Earth's ionosphere, as well as the shortwave propagation conditions. Although the arrival of a high-speed stream from a recurring coronal hole with negative polarity can be expected from July 4, causing unstable geomagnetic conditions, the phenomenon should not last long. In addition, the low flux of electrons with energies greater than 2 MeV is likely to remain, so a return to fairly favorable conditions can be expected.

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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