Weekly forecast

Solar activity forecast for the period August 21 - August 27, 2026

Activity level: low to moderate 
X-ray background flux (1.0-8.0 A): in the range B7.5-C2.5
Radio flux (10.7 cm): a fluctuation in the range: 100-140
Events: class C (3-8/day), class M (2-7/period), class X (0-1/period), proton (0-1/period)
Relative sunspot number (Ri): in the range 35-85

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

Geomagnetic activity forecast for the period August 21 - August 27, 2026

Quiet:   Aug 24 - 27
Unsettled: Aug 21 - 24
Active:  Aug 20 - 21
Minor storm: possible Jul 21
Major storm:  0
Severe storm: 0
First half of currently forecasted period, we expect current active conditions subside.
Two coming days, we expect the condition at most unsettled to active. Then, since August 21, we expect a partial decrease to purely unsettled level. 
Since August 25, we expect at most quiet conditions return.

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 21 - August 27, 2026

Earlier this week, an active region—referred to as AR 4499 during the previous solar rotation—was approaching the northeastern limb of the solar disk. It emerged as AR 4513 on August 19. All four remaining active regions were located on the western side of the solar disk; therefore, had AR 4513 not emerged, there would have been a noticeable decline in overall solar activity. As it stands, however, solar activity will remain at its current level through the end of August, although it remains lower than during the previous solar rotation. Given the two larger coronal holes on the western half of the solar disk, it is no surprise that the solar wind is intensifying intermittently, contributing to slightly increased geomagnetic activity and, consequently, to intermittently deteriorating shortwave propagation conditions.

However, a decline in solar activity will eventually occur, as early as the first third of September. Even before then, however, we can tentatively expect a decrease in the Earth’s magnetic field activity. Given the current seasonal changes, as summer comes to an end in the ionosphere, we can expect calmer and more stable shortwave propagation conditions not only toward the end of August but also throughout most of the first half of September.

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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