Solar activity forecast for the period May 13 - May 19, 2022

Activity level: medium
X-ray background flux (1.0-8.0 A): in the range C1.2- C2.4
Radio flux (10.7 cm): a fluctuation in the range 120-135
Events: class C (1-10/day), class M (1-8/period), class X (0-3/period), proton (0-1/period)
Relative sunspot number (Ri): in the range 75-140

Simona Beerova
RWC Prague, Astronomical Institute, Solar Dept., Ondrejov, Czech Republic
e-mail: sunwatch(at)

Geomagnetic activity forecast for the period May 13 - May 19, 2022

Quiet: May 13, 16 - 18
Unsettled: May 14 - 16
Active: May 14, 19
Minor storm: possible May 19
Major storm: 0
Severe storm: 0

Geomagnetic activity summary:
Solar wind velocity is currently low.
Most of next week, we expect quiet to unsettled conditions (with 
possible isolated active event about Sunday, May 15) till Wednesday, May 
18. The last day of current pereiod, Thursday, May 19, further active 
episode is possible following the last CME.

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 13 - May 19, 2022

eekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere
- May 12, 2022
(Free continuation of my Earth's magnetic field activity predictions,
published between 1978 - 2021.)

Solar flares continue to occur, and some of them are throwing several
overlapping CMEs into space. The amount of CMEs leaving the sun is large
enough to make it difficult to unravel their different shapes and
trajectories, which reduces the reliability of predictions. Nevertheless,
the geomagmetic activity is mostly low, which can be explained by the fact
that the magnetic fields above the solar surface are mostly closed.
An intense solar flare of class X1.5 was observed on May 10 at 1355 UT in
the active region 3006 with a complex magnetic structure. Radiation from
the flare ionized the Earth's atmosphere and caused a shortwave radio
outage around the Atlantic Ocean, more specifically from Central Europe to
the east coast of the United States (see Dellinger effect, or sometimes
Mögel-Dellinger effect). Radio transmissions at frequencies below ~ 30 MHz
were attenuated for more than an hour after the eruption.
Another M-flare on the afternoon of May 11 was a proton flare.
Another CME on May 11 came from the sunspots on the far side - one just
behind the eastern limb of the Sun and the other just behind the western
limb. We do not expect the solar wind around the Earth to intensify again.

F. K. Janda, A.R.S. OK1HH
Emails: ok1hh(at), ok1hh(at)