\n<\/p>\n
Solar activity was at high levels for most of the week, dominated by
Region 4366. The most notable event was an impulsive X4.2 flare from
that region on February 4. Throughout the period, Region 4366
continued to exhibit a slight reduction in area and a modest
simplification of its magnetic complexity. The remaining numbered
regions on the visible disk remained stable or in a state of slight
decay.
\u00a0
Three eruptions were observed in coronagraph imagery during the
period. First was a coronal mass ejection (CME) off the southeastern
limb, first observed in C2 imagery on February 4, and was likely
associated with flaring near Regions 4370 and 4371. This event was
followed by post-eruptive arcades also on February 4 at the same
location, which further confirmed the source region despite flare
activity being partially obscured by Region 4366. Modeling indicates
no Earth-directed component.
\u00a0
The second was a narrow eruption to the NNW, first seen in C2
imagery on February 4. While potentially associated with the
aforementioned X4.2 event, it dissipated quickly and its analysis is
low confidence. Lastly, there was another narrow eruption noted off
the NE, first visible in SOHO\/LASCO C2 imagery. This event was
likely a sympathetic eruption triggered by the X4.2, starting
between Regions 4366 and 4367.
\u00a0
There is a slight potential of minor glancing blows from these
eruptions early on February 8.
\u00a0
Solar wind parameters initially reflected nominal background
conditions before showing a clear disturbance beginning February 3.
Solar wind speed remained in a slow-wind regime, gradually
increasing from about 290 km\/s to a peak near 340 km\/s.
\u00a0
Weekly Commentary on the Sun, the Magnetosphere, and the Earth’s
Ionosphere, February 5, 2026, by F. K. Janda, OK1HH:<\/p>\n
Solar activity has increased again, so the maximum of the 25th
eleven-year cycle continues. This time, active region No. 4366 is
primarily responsible for this. It suddenly emerged on January 30 in
the southeast of the solar disk in a simple Beta magnetic
configuration. The next day, it did not grow, but changed its
configuration to Beta-Gamma-Delta, allowing for larger solar flares.
Then, on February 1, it increased its area tenfold, while an
extremely strong proton flare was observed in it, peaking on
February 2 at 0002 UT.<\/p>\n
Until February 4, it had further doubled in size, with the magnetic
configuration remaining Beta-Gamma-Delta, while the production of
energetically significant flares continued. One to two X-class
flares and several M-class flares are recorded daily, while on
February 4, active region No. 4366 crossed the central meridian.<\/p>\n
This further increased the likelihood of the Earth being hit by an
intensified solar wind and the occurrence of stronger geomagnetic
disturbances. Their onset was mostly predicted for February 5, with
the possibility of occurring one or two days earlier. This is what
happened, with the arrival of the CME recorded on February 4 at 1421
UT and a G1 (Minor) geomagnetic disturbance developing. It is
expected to continue until February 6 or possibly February 7. At the
same time, the production of energetically significant flares could
continue in active region No. 4366 until February 7. At the same
time, there will continue a period of slightly increased probability
of the Earth being hit by proton of solar origin. A decrease in
solar and geomagnetic activity is expected in the following days.<\/p>\n
The Predicted Planetary A Index for February 7 to February 13 is 8,
8, 10, 8, 8, 5 and 20, with a mean of 9.5. Predicted Planetary K
Index is 3, 3, 3, 3, 3, 2, and 5 with a mean of 3.1. 10.7-centimeter
flux is 125, 130, 135, 140, 135, 140, and 145, with a mean of 135.7.<\/p>\n
For more information concerning shortwave radio propagation, see
and the ARRL Technical Information
Service web page at, For
an explanation of numbers used in this bulletin, see
. Information and
tutorials on propagation can be found at, .<\/p>\n
Also, check this:<\/p>\n
https:\/\/bit.ly\/3Rc8Njt<\/p>\n