Weekly forecast

Solar activity forecast for the period May 09 - May 15, 2025

Activity level: low to moderate
X-ray background flux (1.0-8.0 A): in the range B8.0-C5.0
Radio flux (10.7 cm): a fluctuation in the range 112-182
Events: class C (2-11/day), class M (0-6/period), class X (0-1/period), proton (0-1/period)
Relative sunspot number (Ri): in the range 52-178

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

Geomagnetic activity forecast for the period May 09 - May 15, 2025

Quiet: May 10 - 11, 13
Unsettled: May 9 - 11, 13 - 15
Active: May 9, 11 - 12, 15
Minor storm: May 11 - 12, 15
Major storm:  0
Severe storm: 0

Next week, we expect between two and three active events. 
The most one can occur about Monday, May 12.
We expect also an active event tomorrow, Friday, May 9, an at the end of currently forecasted period, about Thursday, May 15.
Between these events, we expect at most unsettled conditions with only a few quiet days.

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 May 09 - May 15, 2025

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere – May 8, 2025

Although we were expecting more activity in the relatively large sunspot group AR 4079 that crossed the central meridian on May 4, it did not happen. Indeed, its magnetic configuration did not promise it. Instead, a sufficiently fast and proton- and especially free-electron-rich solar wind blew from the edges of the coronal holes, which for most of the past days since the beginning of May caused not only increased geomagnetic activity, but also increased attenuation and scattering of radio waves in the ionosphere.

Only a slight improvement in the situation can be predicted. In a few days, the only one major active region that we know about thanks to helioseismology should appear on the eastern limb of the solar disk. Again, it is likely to be the only one in the disk, while the small number of remaining ones will more or less not contribute to the overall level of solar activity.

It remains the case that solar activity is likely to shift from the southern hemisphere to the northern hemisphere this year, but this will probably not yet happen in May.

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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