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Solar activity forecast for the period January 23 - January 29, 2026

Activity level: low to moderate
X-ray background flux (1.0-8.0 A): in the range B7.0-C3.5
Radio flux (10.7 cm): a fluctuation in the range 148-207
Events: class C (3-12/day), class M (1-4/period), class X (0-1/period), proton (0-1/period)
Relative sunspot number (Ri): in the range 73-166

Karolina Knesplova
RWC Prague, Astronomical Institute, Solar Dept., Ondrejov, Czech Republic 

Geomagnetic activity forecast for the period January 23 - January 29, 2026

Quiet: Jan 25 - 27
Unsettled: Jan 23 - 24
Active: Jan 28 - 29
Minor storm:   Jan 29
Major storm:  0
Severe storm: 0

The last Monday, January 19, the geomagnetic activity reached its maximum. The local K-index reached level 8.
Currently, we record a partial geomagnetic activity decrease to unsettled level.
Since Sunday, January 25, quiet to unsettled conditions are expected till Wednesday, January 28.
The last day of currently forecasted period, an another active episode with storming event 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 January 23 - January 29, 2026

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere, January 22, 2026

A combination of favorable circumstances contributed to the northern lights on the night of January 19-20 becoming one of the main stories in the media in the following days. In particular, much of Europe enjoyed very favorable weather conditions thanks to an extensive high-pressure system, the center of which slowly moved southward from Russia across Ukraine, the Black Sea, and Turkey to the Middle East. In its western part, a dry, cold wind blew from the south. As a result, the aurora borealis was observed as far south as southern Europe, for example in southern France, northern Italy, and Romania.

Before the disturbance, a sunspot group AR4341, had been gradually growing. Its magnetic configuration became increasingly complex, while to the west and south of it lay the extensive coronal hole No. 15. Then, in a position near the center of the solar disk, very favorable for the Earth to be hit by solar wind, a proton flare with the highest concentration and energy of protons in the last 36 years was observed. The beginning of the phenomenon was registered on January 18 at 1727 UT, with a maximum at 1809 UT and an end at 1851 UT.

A very fast particle ejection (CME) began on January 18 at 1748 UT, lasted 5 hours, while was best observed around 1812 UT. The particle flow velocity was extreme, ranging from 2900 up to 3500 km/s. Therefore, the geomagnetic disturbance did not begin two to three days after the flare, as is usual, but the very next day – January 19. The aurora borealis was visible for most of the night from January 19 to 20, and even at mid-latitudes it had not only the usual red color, but also, exceptionally, green.

The G4 geomagnetic disturbance lasted 15 hours and was followed by a G3 disturbance lasting 18 hours. The occurrence of numerous inhomogeneities in the ionosphere caused large and variable attenuation. On the other hand, the values of the critical frequencies of the F2 ionospheric layer during the daytime in mid-latitudes on January 19 and 20 were above average. The decline, typical for the end of the disruption, did not occur until January 21.

Solar activity at the end of December indicated that the maximum of the eleven-year cycle is not yet over and will extend from 2024–2025 into part of 2026. During the rest of January, solar activity will decline only very slowly, with a more significant decline occurring after the beginning of February, when another longer geomagnetic disturbance can be expected.

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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