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Solar activity forecast for the period January 31 - February 06, 2025

Activity level: low to moderate
X-ray background flux (1.0-8.0 A): in the range B9.8-C4.0 
Radio flux (10.7 cm): a fluctuation in the range 148-213
Events: class C (5-15/day), class M (3-12/period), class X (0-1/period), proton (0-1/period)
Relative sunspot number (Ri): in the range 80-170

Vlastislav Feik
RWC Prague, Astronomical Institute, Solar Dept., Ondrejov, Czech Republic

Geomagnetic activity forecast for the period January 31 - February 06, 2025

Quiet: Feb 5 - 6
Unsettled: Jan 31, Feb 2 - 5
Active: Jan 31, Feb 1 - 2
Minor storm: about Feb 1
Major storm:  0
Severe storm: 0

Because of the previous CMEs and the large equatorial holes 11/+4 and 12/+4, we expect the peaking geomagnetic activity during the coming weekend, evening of January 31 and about February 1.
Since February 2, we expect geomagnetic activity decrease to unsettled level.
Last two days, at most quiet conditions can return.

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 January 31 - February 06, 2025

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere – January 30, 2025

January 25 can be considered one of the best days of the last few weeks. This is clearly true for the possibility of QSOs between Europe and the Pacific islands of the Marquesas, where only southbound QTHs from TX7N were free of terrain obstacles. Which in effect implies a preference for propagation via the long path (to Europe via Antarctica and Africa, plus double passage through the mid-latitudes of summer ionosphere of the Earth's southern hemisphere). The improvement on 25 January (as well as the next one on 27 January) can be explained by a combination of persisting high solar activity, low geomagnetic activity, and a favourable polarity of the longitudinal component of the interplanetary magnetic field (but this was only partially true on 27 January).

After most sunspot groups have gone beyond the western limb of the solar disk, total solar activity has decreased. Then coronal holes appeared first in the northeast and then in the southeast of the disk. The solar wind gradually intensified as they progressed towards the central meridian, probably twice. The first time is when the western edge of the northernmost one reaches the central meridian. An increase in geomagnetic activity can therefore be expected as early as 31 January, but should not last long.

A significantly larger and longer disturbance can tentatively be expected later, in the second half of next week, when the eastern edge of the aforementioned coronal hole enters the central meridian region. Due to its proximity to larger sunspot groups, solar wind parameters, geomagnetic activity and ionospheric shortwave propagation conditions will fluctuate significantly, including at best an initial improvement.

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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