Weekly forecast

Solar activity forecast for the period March 31 - April 06, 2023

Activity level: low to moderate (March 31-April 2), very low to low  (April 3-6)
X-ray background flux (1.0-8.0 A): in the range B8.5 - C1.5 
Radio flux (10.7 cm): a fluctuation in the range 134-170
Events: class C (2-15/day), class M (0-4/period), class X (0-1/period), proton (0-1/period)
Relative sunspot number (Ri): in the range 30-130

Bozena Solarova
RWC Prague, Astronomical Institute, Solar Dept., Ondrejov, Czech Republic

Geomagnetic activity forecast for the period March 31 - April 06, 2023

Quiet: Apr 3 - 5
Unsettled: Apr 1 - 3, 6
Active: Mar 31, Apr 1
Minor storm: unlikely Mar 31
Major storm: 0
Severe storm: 0

Next two days, we expect geomagnetic activity at the range of unsettled and active level. The local K-index can reach level 4, minor storming effect is unlike.
Since Sunday, April 2, we expect geomagnetic activity decrease to quiet to unsettled level. As the most quiet days, we expect them about April 4-5.
Last day, more unsettled level is possible.

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 March 31 - April 06, 2023

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere – March 30, 2023

The strong geomagnetic storm that occurred on 23-24 March was not expected. Moreover, it was classified as a G4, making it the most intense in almost 6 years. The source of the solar wind on the Sun was not identified with certainty, but a large coronal hole in the south, near the central meridian, could not be missed.

As a consequence of the disturbance, the ionosphere first experienced a rise in the critical frequencies of the F2 layer on 23 March, followed by a significant drop on 24-25 March. Their normal values started to be registered again only after 26 March.

Energetic flares are a reliable indicator of the increase in solar activity. On March 29, the seventh X-class flare of the year was registered. Yet a total of seven were registered in 2022 and only two in 2021..

Most of the sunspots are now on the western half of the solar disk As they gradually set, total solar activity will first decrease over the next week before rising again.

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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