Týdenní předpověď

Solar activity forecast for the period April 05 - April 11, 2024

Activity level: mostly low
X-ray background flux (1.0-8.0 A): in the range B3.0 - C1.0
Radio flux (10.7 cm): a fluctuation in the range 90-160
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 20-120

Michael Vavra
RWC Prague, Astronomical Institute, Solar Dept., Ondrejov, Czech Republic

Geomagnetic activity forecast for the period April 05 - April 11, 2024

Quiet: Apr 7 - 9
Unsettled: Apr 4 - 5, 10 - 11
Active: Apr 4 - 5, 11
Minor storm: unlikely Apr 4
Major storm: 0
Severe storm: 0

We expect the nearest active event during the coming hours. Another one can be expected at the end of currently forecasted period, i.e. about Thursday, April 11.
Between these potentially active events, we expect quiet to unsettled conditions generally. The quietest period can be expected between Sunday, April 7, and Tuesday, April 9.
About Thursday, April 11, an isolated active event is possible. Nevertheless, we do not expect any storming event about this day.

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 April 05 - April 11, 2024

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere – April 4, 2024

The two large and very active sunspot groups, AR3614 and AR3615, bade us farewell last week by going beyond the western limb of the solar disk. AR3615 still unleashed two powerful M-class flares and an X1 flare that ionized the upper part of the Earth's atmosphere and caused the Dellinger effect over the Pacific Ocean on March 28 (with a maximum at 2053 UT).

AR3615 still managed to produce an M9.4-class solar flare on March 30, which was only one percent weaker than an X-class flare.  After that, we expected particles originating from solar radiation to arrive in the vicinity of Earth, but this did not happen. The development in the following days was therefore relatively quiet.

Due to the calming of the geomagnetic field, we expected an improvement in shortwave propagation conditions. This did occur from 2 April onwards, but was only very slight due to the rapid decrease in solar activity. After the return of active regions to the solar disk, we expect an improvement in propagation conditions, especially in the third decade of April.

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

Odběr týdenních předpovědí

Pro odběr týdenních předpovědí přes email se prosím přihlaste na: sunwatch "at-sign" asu.cas.cz