Weekly forecast

Solar activity forecast for the period April 17 - April 23, 2026

Activity level: low
X-ray background flux (1.0-8.0 A): in the range B2.5-B6.5
Radio flux (10.7 cm): a fluctuation in the range: 90-115
Events: class C (1-6/day), class M (0-2/period), class X (0/period), proton (0/period)
Relative sunspot number (Ri): in the range 44-110

Martina Pavelkova
RWC Prague, Astronomical Institute, Solar Dept., Ondrejov, Czech Republic 

Geomagnetic activity forecast for the period April 17 - April 23, 2026

Quiet:  Apr 21 - 23
Unsettled: Apr 19 - 21
Active: Apr 17 - 18
Minor storm:   Apr 17 - 18
Major storm:  possible about Apr 18
Severe storm: 0

Because of the large coronal hole (42/-4), we expect geomagnetic activity enhance during the coming two days. It can be accompanieed by minor to major storm event, this warning is actual till Sunday, April 19.
Then, since Monday, April 20, we expect a partial activity decrease and, at the end of currently forecasted period, quiet to unsettled conditions return.

Tomas Bayer
RWC Prague
Institute of Geophysics of the ASCR, Prague
Department of Geomagnetism
Budkov observatory (BDV)

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