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Solar activity forecast for the period August 01 - August 07, 2025

Activity level: low to moderate
X-ray background flux (1.0-8.0 A): in the range B4.3-C5.0
Radio flux (10.7 cm): a fluctuation in the range 93-182
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 62-168	

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

Geomagnetic activity forecast for the period August 01 - August 07, 2025

Quiet: Aug 1 - 2, 5 - 6
Unsettled: Aug 2- 4
Active: Aug 3 - 4, 7
Minor storm: unlikely Aug 3 - 4, 7 
Major storm:  0
Severe storm: 0

Next week, we expect two geomagnetic activity peaks.
The first one can occur August 3 - 4 and peak with an active to minor storm event. The second one can come at the end of currently forecasted period, about Thursday, August 7.

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 August 01 - August 07, 2025

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere – July 31, 2025

We are most likely still in the period of the maximum od 11-year solar activity cycle No. 25. Its peak was preliminarily recorded in the fall of 2024, but this year's course was very unusual, while its response in the ionosphere was unexpected, especially in May and June. Solar activity should continue to decline slowly this year, with a more rapid decline expected starting in the 2026. Therefore, there is still hope for favorable shortwave propagation conditions this fall, especially in the shorter part of the range (say, at frequencies above 20 MHz).

Last week, only relatively small sunspot groups were observed on the Sun, with no major flares. This was accompanied by smaller fluctuations in the speed of the solar wind and, therefore, a calmer geomagnetic field. Although the summer season in northern hemisphere of the Earth is not favorable for long-distance shortwave propagation, it was still an improvement over previous months. There should be fewer sunspot groups on the far side of the Sun. But it seems that those that will soon appear will be larger than those we are currently observing...

Solar ultraviolet and X-ray radiation, together with the solar wind, are the main causes of changes in the Earth's ionosphere, but they are not the only ones. The ionosphere also reacts to processes taking place below it. These include gravitational waves (formed at the interface between air masses of different densities, for example in meteorological fronts) and infrasound caused by earthquakes and typhoons. Scientific research into these phenomena is still in its infancy, and although records of changes in the ionosphere following the earthquake on the east coast of Kamchatka (M8.8, Tue 29 Jul 2025, 23:24:51 UTC) are available, for DX signal hunters this is still more of a curiosity.

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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