\n<\/p>\n
Solar activity has been at moderate levels for the past 24 hours. Solar
activity is expected to be low with a chance for M class flares. Solar wind
speed reached a peak of 1124 km\/s.<\/p>\n
Solar activity reached moderate levels following an M2.0 flare (R1-Minor) at
from a region just around the Northwestern limb. Only low-level C-class
activity was observed from the remaining spotted regions on the visible disk.
New Regions 4248 and 4249 were numbered as they emerged late in the period, but
were otherwise unremarkable.<\/p>\n
A chance for R1-R2 (Minor-Moderate) radio blackouts exists over October 10 to 12 due
to flare potential from several active regions returning from the Suns far
side.<\/p>\n
Spaceweather.com reports on October 10, a hole has opened in the sun’s
atmosphere, and it is venting a stream of solar wind directly toward Earth<\/p>\n
Weekly Commentary on the Sun, the Magnetosphere, and the Earth’s Ionosphere \u2013
October 10,2025<\/p>\n
Solar activity has been declining since the beginning of October, as expected.
The last slightly larger sunspot group, designated as active region AR 4236,
disappeared behind the northwestern limb of the solar disk in the middle of the
present week. Almost immediately after it became invisible to us, a moderately
strong eruption occurred. This happened on Thursday, October 9, peaking at
12:31 UTC. However, the decline in solar activity will continue, followed by an
increase that should last for almost the entire second half of October. <\/p>\n
This will include a positive effect on the state of the F2 ionospheric layer.
Although this did not bring such good conditions for shortwave propagation,
precisely because of the decline in solar radiation, there were interesting
improvements here and there \u2013 especially at the beginning of geomagnetic
disturbances, most recently on the afternoon of October 7. However, another
phenomenon played a major role in the surprising improvement in shortwave
propagation conditions between Europe and the Antipodes on October 8 \u2013 the rare
and rather unusual occurrence of a sporadic E layer at this time of year…<\/p>\n
Official forecasts of increased solar activity for the second half of October
are rather skeptical for the time being. This is probably because the activity
on the far side of the Sun, as measured by helioseismological methods, is not
high. However, this may change. A surprise in the form of faster growth cannot
be ruled out.<\/p>\n
The latest report from Dr. Tamitha Skov, WX6SWW, can be found on Youtube.<\/p>\n
The predicted Planetary A Index for October 11 to 17 is 15, 12, 10, 8, 5, 5,
and 5 with a mean of 8.5. The Predicted Planetary K Index is 5, 4, 3, 3, 2, 2
and 2 with a mean of 3. Predicted 10.7 centimeter flux is 140, 135, 135, 140,
135, 140 and 145 with a mean of 137.1.<\/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
“Understanding Solar Indices” from September 2002 QST.
\u00a0<\/p>\n<\/p><\/div>\n