Weekly forecast

Forecast issued date:

Solar activity forecast for the period May 29 - June 04, 2026

Activity level: low to moderate
X-ray background flux (1.0-8.0 A): in the range B6.5-C2.1
Radio flux (10.7 cm): a fluctuation in the range: 126-177
Events: class C (1-8/day), class M (0-4/period), class X (0/period), proton (0/period)
Relative sunspot number (Ri): in the range 95-186

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

Geomagnetic activity forecast for the period May 29 - June 04, 2026

Quiet:   Jun 1, 4
Unsettled: May 29 - 30, 27
Active: May 29 - 30, Jun 2 - 3
Minor storm:   May 30 - 31
Major storm:  0
Severe storm: 0

Coming days, we expect a geomagnetic activity enhancement because of the last partial halo CME.
We expect the highest geomagnetic activity at the turn of May and June, then, at most a partial decrease to at most 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 May 29 - June 04, 2026

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere, May 28, 2026

Observations of the far side of the Sun by the Solar Orbiter probe showed us how a new and relatively large active region was approaching the northeastern limb of the solar disk. But it wasn’t until it began to emerge on May 28 (designated as AR 4455) that it became clear the recent rise in solar activity would continue. Furthermore, the only significant coronal hole in the higher northern heliographic latitudes is sufficiently far from other active regions, so we need not expect a significant intensification of the solar wind.

Therefore, we could expect calmer conditions in the Earth’s magnetosphere and, at the same time, higher usable frequencies in the ionosphere for long-distance communications before their seasonal decline. However, summer in the ionosphere of the Earth’s northern hemisphere, with higher attenuation in the lower ionosphere during the long days, will often be enlivened by sporadic E layers in the mid-latitudes until August.

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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