Hvezdáreň Roztoky

April 23 – 29, 2021

Solar activity forecast for the period April 23 – 29, 2021

Issued: 2021 Apr 22 2100 UTC

Activity level from Apr 23 to Apr 26: mostly low
X-ray background flux (1.0-8.0 A): in the range A5.0-B5.0
Radio flux (10.7 cm): a fluctuation in the range 75-95 f.u.
Events: class C (0-5/day), class M (0-1/period), class X (0/period), proton (0/period)
Relative sunspot number (Ri): in the range 11-45

Activity level from Apr 27 to Apr 29: very low to low
X-ray background flux (1.0-8.0 A): in the range A3.0-B3.0
Radio flux (10.7 cm): a fluctuation in the range 70-90 f.u.
Events: class C (0-2/day), class M (0/period), class X (0/period), proton (0/period)
Relative sunspot number (Ri): in the range 0-40

Jozef Lesko
Roztoky Observatory, Slovak Republic
e-mail: safor (at) protonmail.ch

Geomagnetic activity forecast for the period April 23 – 29, 2021

Issued: 2021 Apr 22 2130 UTC

Quiet to unsettled: Apr 27 – 29
Quiet to active: Apr 23 – 26

Jozef Lesko
Roztoky Observatory, Slovak Republic
e-mail: safor (at) protonmail.ch