Weekly forecast

Solar activity forecast for the period January 03 - January 09, 2025

Activity level: moderate
X-ray background flux (1.0-8.0 A): in the range C1.5 - C4.3
Radio flux (10.7 cm): a fluctuation in the range 160-250
Events: class C (4-16/day), class M (4-14/period), class X (0-1/period), proton (0-1/period)
Relative sunspot number (Ri): in the range 90-220

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

Geomagnetic activity forecast for the period January 03 - January 09, 2025

Quiet: Jan 3 - 4, 8 - 9
Unsettled: Jan 4, 6 - 8
Active: Jan 5 - 6
Minor storm: Jan 5
Major storm:  0
Severe storm: 0

The last magnetic storm was the strongest during the last half-year. At the Budkov observatory, the local K-index has reached value 8.
Next two days, we expect quiet to unsettled conditions return.
About the coming weekend, another geomagnetic activity enhancement is possible. Because of the last CME, we can expect any active event with possible stroming event about Sunday, January 5. Unsettled to active conditions can be expected also during the following days, till January 7.

The last days, we expect quiet to unsettled conditions 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 03 - January 09, 2025

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere – January 2, 2025

Considering the high solar flare activity, there was a relatively high probability of an increase in geomagnetic activity during the Christmas holidays. However, currents of enhanced solar wind avoided the Earth and therefore it was surprisingly quiet for a relatively long period from Christmas almost until the end of the year, more precisely from 25 to 30 December. Strong solar flares in the last two days of December were followed by CMEs that were at least partially directed towards the Earth. Which prompted all geomagnetic field activity forecasters to jointly and indiscriminately predict the occurrence of geomagnetic disturbances and auroras for 31 December and 1 January.

The particles ejected by the second of the major eruptions hit the Earth more effectively. Therefore the geomagnetic disturbance on 31 December was weaker. The major disturbance on January 1, 2025 was accompanied by beautiful auroras. At first approximation, the unexpected development of ionospheric shortwave propagation on New Year's Day may have seemed surprising. Not only were they not bad, but their development was irregular, while the MUF values were even above average. The cause can be found also in the previous calm development (25 to 30 December) and also in the fact that the solar wind speed started to increase gradually only from 1 January.

The most active regions on the Sun now fall behind the western limb of the solar disk. Therefore solar activity will slowly decrease. But it will be sufficient to open all shortwave bands. At the same time, the Earth's magnetic field activity will also be decreasing, so the evolution of ionospheric propagation conditions should be more stable, while remain mostly above average on most days.

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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