11/01/2024

Solar activity increased this week. Average daily sunspot number
went from 127.7 to 197.4 and average solar flux from 170.5 to 240.2.

Predicted solar flux is 270 on November 1-2, 265 and 260 on November
3-4, 250 on November 5-7, 214, 195 and 182 on November 8-10, 172,
168, 174 and 165 on November 11-14, and 162 on November 15-16.

Predicted planetary A index is 5, 8, 15, and 10 on November 1-4, 5
on November 5-15, then 5, 8, 5, 12, and 8 on November 16-20, and 5
on November 21 through December 5

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere - October 31, 2024 from OK1HH:

"We know only approximately what the Earth's ionosphere looked like
between March 1755 and June 1766 thanks to observations of the Sun
in Solar Cycle 1. But we do know what it looked like in Solar Cycle
19, which ran from April 1954 to October 1964. Although I was a
novice radio amateur at the time, I can testify that the shortwave
propagation conditions at the peak of Solar Cycle 19 (1958) were
wonderful!

"As of December 2019, Solar Cycle 25 is in operation. It was
supposed to be low, fortunately it is not. Its maximum is now
underway, perhaps a second will follow next year. It is fabulous,
judging by the above and the many interesting effects, including,
for example, auroras. But unfortunately, not if we judge them by the
current conditions of ionospheric shortwave propagation. An
explanation of why this is now the case will surely be forthcoming -
but perhaps Solar Cycle 26 will be underway.

"A week ago, as expected, large active regions and corresponding
groups of spots appeared at the southeastern limb of the solar disk.
We are now seeing them near the central meridian. This has increased
the likelihood of Earth being hit by particles that will eject
subsequent flares. It seems that not only these, but also
disturbances in the geomagnetic field and then fluctuations in the
ionospheric propagation field can be counted on with certainty in
the coming days. Given that we have already seen simultaneously
observed active regions on the Sun during the last solar rotation,
presumably a 27-day recurrence will be a good aid to prediction."

How NASA tracks the Solar Cycles:

https://www.dailymotion.com/video/x98c2di[1]

The latest from the Solar-Terrestrial Centre of Excellence
Newsletter:

https://www.stce.be/newsletter/newsletter.php[2]

Send your tips, reports, observations, questions and comments to k7ra@arrl.net[3]. When reporting observations, don't forget to tell us
which mode you were operating.

For more information concerning shortwave radio propagation, see http://www.arrl.org/propagation[4] and the ARRL Technical Information
Service web page at, http://arrl.org/propagation-of-rf-signals[5]. For
an explanation of numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere[6] .

An archive of past propagation bulletins is at http://arrl.org/w1aw-bulletins-archive-propagation [7]. More good
information and tutorials on propagation are at http://k9la.us/[8] .

Also, check this article:

https://bit.ly/3Rc8Njt[9]

"Understanding Solar Indices" from September 2002 QST.

Instructions for starting or ending email subscriptions to ARRL
bulletins are at http://arrl.org/bulletins[10] .

Sunspot numbers for October 24 through 30 2024 were 138, 157, 181,
198, 288, 220, and 200, with a mean of 197.4. 10.7 cm flux was
196.6, 209.3, 238.4, 246.2, 255.5, 265.6, and 269.8, with a mean of
240.2. Estimated planetary A indices were 13, 3, 14, 10, 17, 12, and
15, with a mean of 12. Middle latitude A Index was 10, 2, 11, 8, 11,
10, and 10, with a mean of 8.9.

ÿ


[1] https://www.dailymotion.com/video/x98c2di
[2] https://www.stce.be/newsletter/newsletter.php
[3] mailto:k7ra@arrl.net
[4] http://www.arrl.org/propagation
[5] http://arrl.org/propagation-of-rf-signals
[6] http://arrl.org/the-sun-the-earth-the-ionosphere
[7] http://arrl.org/w1aw-bulletins-archive-propagation
[8] http://k9la.us/
[9] https://bit.ly/3Rc8Njt
[10] http://arrl.org/bulletins

---
þ Synchronet þ Whiskey Lover's Amateur Radio BBS

11/15/2024

Only five new sunspot groups emerged this week. First was on
November 7, next on November 9, two more on November 11, and another
on November 13.

Average daily sunspot number declined from 193.4 to 141.6, while
average daily solar flux went from 248.4 to 203.7.

Predicted solar flux is 145 on November 15-16, 155 on November
17-18, then 145 on November 19, 140 November 20-21, then 235, 240,
255 and 260 on November 22-25, 270 on November 26-27, then 255 and
250 on November 28-29, 240 on November 30 and December 1, 230 on
December 2-3, and 225 and 220 on December 4-5, then 225 on December 6-7, and 175, 170, and 175 on December 8-10, then 165 on December 11-14, 178 and 185 on December 15-16, 200 on December 17-18, then 235, 240, 255 and 260 on December 19-22.

Estimated planetary A index is 12, 10, 8, 12 and 8 on November
15-19, 5 on November 20-24, 10 on November 25-26, then 8, 5, 5 and
10 on November 27-30, then 12, 9, 8, 7 and 5 on December 1-5, 12 on
December 6-8, then 8, 12 and 10 on December 9-11, 8 on December
12-13, then 5, 8, 5 and 12 on December 14-17.

From HMI Science Nuggets, a possible explanation for solar cycle
double peaks:

http://hmi.stanford.edu/hminuggets/?p=2685[1]

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere - November 14, 2024, from F.K. Janda, OK1HH:

"Of the three active regions in the past few days, two have fallen
behind the western limb of the solar disk. Therefore, the solar flux
has dropped significantly. The third sunspot group was AR3889, which
crossed the central meridian midweek. Its size of over 400
millionths of the solar disk area, and in particular the optical 'F'
and magnetic 'Beta-Gamma-Delta' configurations, indicate that the
production of moderate size flares will continue. So, because it is
in the west, like most coronal holes, the solar wind should
intensify, and the Earth's magnetic field activity should increase.

"This development, in fact, has already begun on November 14. First,
conditions worsened after the polarity of the longitudinal component
of the interplanetary magnetic field changed to negative between
0200-0500 UTC, while the density of protons in the solar wind
increased. This was correctly followed by an increase in its
velocity from 350 km/s to 440 km/s. Due to the anticipated increase
in the solar wind, a further several days of turbulence is expected,
followed by calming down only during the following week."

The latest report from Dr. Tamitha Skov, WX6SWW:

https://youtu.be/lGpDztCtTwY[2]

Send your tips, reports, observations, questions and comments to k7ra@arrl.net[3]. When reporting observations, don't forget to tell us
which mode you were operating.

For more information concerning shortwave radio propagation, see http://www.arrl.org/propagation[4] and the ARRL Technical Information
Service web page at, http://arrl.org/propagation-of-rf-signals[5]. For
an explanation of numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere[6] .

An archive of past propagation bulletins is at http://arrl.org/w1aw-bulletins-archive-propagation[7] . More good
information and tutorials on propagation are at http://k9la.us/[8] .

Also, check this article:

https://bit.ly/3Rc8Njt[9]

"Understanding Solar Indices" from September 2002 QST.

Instructions for starting or ending email subscriptions to ARRL
bulletins are at http://arrl.org/bulletins[10] .

Sunspot numbers for November 7 through 13, 2024 were 164, 167, 176,
121, 138, 116, and 109, with a mean of 141.6. 10.7 cm flux was
239.2, 231, 220.9, 230.6, 182.2, 171.7, and 150.3, with a mean of
203.7. Estimated planetary A indices were 9, 11, 32, 25, 10, 5, and
7, with a mean of 14.1. Middle latitude A Index was 7, 7, 24, 15, 7,
4, and 5, with a mean of 9.9.
ÿ


[1] http://hmi.stanford.edu/hminuggets/?p=2685
[2] https://youtu.be/lGpDztCtTwY
[3] mailto:k7ra@arrl.net
[4] http://www.arrl.org/propagation
[5] http://arrl.org/propagation-of-rf-signals
[6] http://arrl.org/the-sun-the-earth-the-ionosphere
[7] http://arrl.org/w1aw-bulletins-archive-propagation
[8] http://k9la.us/
[9] https://bit.ly/3Rc8Njt
[10] http://arrl.org/bulletins

---
þ Synchronet þ Whiskey Lover's Amateur Radio BBS

11/22/2024

Solar activity was lower this reporting week, November 14-20, with
the average daily sunspot number down from 141.6 to 99.3, and solar
flux from 203.7 to 152.4. Geomagnetic indicators were quiet.

This follows a period during August and October when it seemed we
must be at the peak of Solar Cycle 25. But we won't know that until
nearly a year after solar max, when a long moving average of daily
sunspot numbers is examined.

Predicted solar flux is 170 on November 22, 175 on November 23-24,
180 on November 25-26, 175 and 180 on November 27-28, 250 on
November 29-30, then 240, 230, 220, and 210 on December 1-4, 205 on
December 5-6, then 200, 180, 170 and 150 on December 7-10, 145 on
December 11-12, then 149, 145, and 230 on December 13-15, 235 on
December 16-17, 240 on December 18-20, 245 on December 21-22, then
240, 245 and 255 on December 23-25.

Predicted planetary A index is 8 on November 22-25, 5 on November
26-29, then 10, 12, 9, 8, 7 and 5 on November 30 through December 5,
12 on December 6-7, then 10, 5, 5, 10, 15 and 10 on November 8-13,
then 8 on December 14-15, then 5 and 12 on December 16-17, and 5 on
December 18-21.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere - November 21, 2024, from F. K. Janda, OK1HH:

"During November, solar activity was relatively lowest in the middle
of the month, which happened after the large sunspot groups in the
west of the disk had set and before the larger groups in the east
came out. The largest of these is designated AR3901 and will pass
through the central meridian on November 23. Solar activity will
therefore still increase slightly. A more significant rise could
perhaps be expected after the rise of the other groups, but their
current activity on the far side of the Sun does not appear to be
great for now.

"The low number and small area of coronal holes are the likely cause
of the geomagnetically quieter development, which is likely to
continue.

"November belongs to the Autumn DX season, Therefore we can expect
continued above-average shortwave propagation. They were admittedly
a little worse as a result of the drop in solar radiation, but the
rest of the month could, yet, correct this. Which is true for the
northern hemisphere of the Earth, where the season of favorable
propagation conditions on the longer shortwave bands is already
beginning!"

Images from the European Space Agency:

https://tinyurl.com/42r665y9[1]

From "Space Daily," solar orbiter images:

https://tinyurl.com/bdz33ake[2]

https://tinyurl.com/yvkf66u2[3]

Send your tips, reports, observations, questions and comments to k7ra@arrl.net[4]. When reporting observations, don't forget to tell us
which mode you were operating.

For more information concerning shortwave radio propagation, see http://www.arrl.org/propagation[5] and the ARRL Technical Information
Service web page at, http://arrl.org/propagation-of-rf-signals[6] . For
an explanation of numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere[7] .

An archive of past propagation bulletins is at http://arrl.org/w1aw-bulletins-archive-propagation[8] . More good
information and tutorials on propagation are at http://k9la.us/[9] .

Also, check this:

https://bit.ly/3Rc8Njt[10]

"Understanding Solar Indices" from September 2002 QST.

Instructions for starting or ending email subscriptions to ARRL
bulletins are at http://arrl.org/bulletins[11] .

Sunspot numbers for November 14 through 20, 2024 were 96, 71, 71,
117, 118, 109, and 113, with a mean of 99.3. 10.7 cm flux was 146.8,
148.9, 139.9, 146.3, 165, 157.2, and 162.6, with a mean of 152.4.
Estimated planetary A indices were 11, 13, 8, 8, 4, 9, and 9, with a
mean of 8.9. Middle latitude A Index was 10, 10, 8, 6, 3, 6, and 8,
with a mean of 7.3.

ÿ


[1] https://tinyurl.com/42r665y9
[2] https://tinyurl.com/bdz33ake
[3] https://tinyurl.com/yvkf66u2
[4] mailto:k7ra@arrl.net
[5] http://www.arrl.org/propagation
[6] http://arrl.org/propagation-of-rf-signals
[7] http://arrl.org/the-sun-the-earth-the-ionosphere
[8] http://arrl.org/w1aw-bulletins-archive-propagation
[9] http://k9la.us/
[10] https://bit.ly/3Rc8Njt
[11] http://arrl.org/bulletins

---
þ Synchronet þ Whiskey Lover's Amateur Radio BBS

12/02/2024

ARRL Headquarters was closed on November 29. So, this regular Friday
bulletin was moved to the following Monday (12/2).

Solar activity increased during the current reporting week, November
21-27. Average daily sunspot number rose to 155.7, and average daily
solar flux was 282.2.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere - November 28, 2024, by F. K. Janda, OK1HH:

"After the unexpected solar proton flare of 21 November, which took
place beyond the Sun's western limb, a rain of higher-energy protons
hit the Earth's atmosphere. This solar radiation storm had a greater
impact at higher latitudes in the southern hemisphere, where it
caused a significant increase in attenuation.

"Two days later, two new large sunspot groups appeared near the
southeastern limb of the Sun. These produced moderate eruptions
daily, which is more or less normal for the 11-year maximum. These
are AR3905 and AR3906, which have grown rapidly to a size where they
can be observed with the naked eye. There is a relatively small
coronal hole near them that could be influencing the solar wind
enhancement.

"Following the eruption of a plasma filament near AR3901, a G2 class geomagnetic storm is possible on November 28-29, when a CME is
expected to impact. However, around 1900 UT on November 28, when
this information is written as usual, nothing is still happening. We
will see what happens next. It is quite possible that the plasma
cloud will only hit the Earth a little and it is also not out of the
question that it will miss the Earth completely. So, any prediction
at this point has a low probability of coming true."

New video from Dr. Tamitha Skov, WX6SWW:

https://youtu.be/1P4sCwn8TZI[1]

Send your tips, reports, observations, questions and comments to k7ra@arrl.net[2]. When reporting observations, don't forget to tell us
which mode you were operating.

For more information concerning shortwave radio propagation, see http://www.arrl.org/propagation[3] and the ARRL Technical Information
Service web page at, http://arrl.org/propagation-of-rf-signals[4]. For
an explanation of numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere[5] .

An archive of past propagation bulletins is at http://arrl.org/w1aw-bulletins-archive-propagation[6] . More good
information and tutorials on propagation are at http://k9la.us/[7] .

Also, check this:

https://bit.ly/3Rc8Njt[8]

"Understanding Solar Indices" from September 2002 QST.

Instructions for starting or ending email subscriptions to ARRL
bulletins are at http://arrl.org/bulletins[9] .

Sunspot numbers for November 21 through 27, 2024 were 148, 170, 156,
164, 140, 163, and 141, with a mean of 155.7. 10.7 cm flux was
166.2, 179.1, 199.9, 202.7, 220.4, 222.3, and 225, with a mean of
202.2. Estimated planetary A indices were 8, 12, 8, 7, 11, 7, and 5,
with a mean of 8.3. Middle latitude A Index was 5, 10, 7, 7, 9, 6,
and 3, with a mean of 6.7.
ÿ


[1] https://youtu.be/1P4sCwn8TZI
[2] mailto:k7ra@arrl.net
[3] http://www.arrl.org/propagation
[4] http://arrl.org/propagation-of-rf-signals
[5] http://arrl.org/the-sun-the-earth-the-ionosphere
[6] http://arrl.org/w1aw-bulletins-archive-propagation
[7] http://k9la.us/
[8] https://bit.ly/3Rc8Njt
[9] http://arrl.org/bulletins

---
þ Synchronet þ Whiskey Lover's Amateur Radio BBS

12/06/2024

Solar activity seems to have dropped dramatically from a recent peak.ÿ Are we over the cycle peak and headed down again?ÿ Too early to say.

Daily average sunspot numbers this week sank to 120.1.

Predicted solar flux is 175 on December 6 to 8, 170 on December 9 and 10, 175 on December 11 and 12, and 205 on December 13 to 17.

Predicted planetary A index is 8 on December 6 and 7, 5 on December to 12, 10, 8 and 5 on December 13 to 15, 8 on December 16 to 18, 12 and 8 on December 19 and 20 and 5 on December 21 through January 6, 2025.

Commentary from OK1HH:

"After the unexpected solar proton flare of 21 November, which took place beyond the Sun's western limb, a rain of higher-energy protons hit the Earth's atmosphere.ÿ This solar radiation storm had a greater impact at higher latitudes in the southern hemisphere, where it caused a significant increase in attenuation.

"Two days later, two new large sunspot groups appeared near the southeastern limb of the Sun.ÿ These produced moderate eruptions daily, which is more or less normal for the 11-year maximum.ÿ These are AR3905 and AR3906, which have grown rapidly to a size where they can be observed with the naked eye.ÿ There is a relatively small coronal hole near them that could be influencing the solar wind enhancement.

"Following the eruption of a plasma filament near AR3901, a G2 class geomagnetic storm is possible on November 28 and 29, when a CME is expected to impact.ÿ However, around 1900 UT on November 28, when this information is written as usual, nothing is still happening. We will see what happens next.
It is quite possible that the plasma cloud will only hit the Earth a little and it is also not out of the question that it will miss the Earth completely.ÿ So any prediction at this point has a low probability of coming true."

Send your tips, reports, observations, questions and comments to k7ra@arrl.net[1].ÿ When reporting observations, don't forget to tell us which mode you were operating.

For more information concerning shortwave radio propagation, see http://www.arrl.org/propagation[2] and the ARRL Technical Information Service web page at, http://arrl.org/propagation-of-rf-signals[3] .

For an explanation of numbers used in this bulletin, see

http://arrl.org/the-sun-the-earth-the-ionosphere[4] .

An archive of past propagation bulletins is at

http://arrl.org/w1aw-bulletins-archive-propagation[5]ÿ

More good information and tutorials are at http://k9la.us/[6].

Also, check "Understanding Solar Indices" from September 2002 QST: https://bit.ly/3Rc8Njt[7] .

Instructions for starting or ending email subscriptions to ARRL bulletins are at http://arrl.org/bulletins[8] .

ÿSunspot numbers for November 28 through December 4, 2024 were 149, 162, 103, 83, 113, 126, and 105, with a mean of 120.1.ÿ 10.7 cm flux was 213.9, 219.8, 204, 186.3, 185.3, 174.2, and 174.7, with a mean of 202.2.ÿ Estimated planetary A indices were 4, 8, 11, 7, 6, 13, and 7, with a mean of 8.3.ÿ Middle latitude A Index was 3, 6, 9, 6, 6, 6, 10, and 5, with a mean of 6.


[1] mailto:k7ra@arrl.net
[2] http://www.arrl.org/propagation
[3] http://arrl.org/propagation-of-rf-signals
[4] http://arrl.org/the-sun-the-earth-the-ionosphere
[5] http://arrl.org/w1aw-bulletins-archive-propagation
[6] http://k9la.us/
[7] https://bit.ly/3Rc8Njt
[8] http://arrl.org/bulletins

---
þ Synchronet þ Whiskey Lover's Amateur Radio BBS

Re: The K7RA Solar Update
By: ARRL de WD1CKS to QST on Fri Dec 06 2024 22:38:54

...AR3905 and AR3906, which have grown rapidly to a size where they can be observed with the naked eye.

But would you really want to?

---
þ Synchronet þ End Of The Line BBS - endofthelinebbs.com

12/13/2024

Average daily sunspot number plummeted to 104.4.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere for December 12, 2024 from OK1HH:

"The high solar activity in October this year suggests that this may have been the peak of an 11-year cycle.ÿ This is not to say that solar activity will not continue to rise.ÿ On the contrary, it may well be that the first maximum of the cycle took place in October and that we can look forward to a second maximum.ÿ This could take place in 2025 or 2026 at the latest, but it will be followed by a decline.

"Solar activity in November was lower and December's is even lower. The expected geomagnetic disturbance, predicted for 29 November, did not take place because the CME did not affect the Earth.ÿ However, the almost daily occurrence of moderate solar flares continued and a large flare occurred.ÿ It happened on 8 December at around 0906 UT. However, even after this eruption no major geomagnetic disturbance followed and the changes in ionospheric shortwave propagation were rather random."

In December, the Sun is quieter, and large sunspot groups do not occur in its photosphere.ÿ The only major active regions we see are to the south of the solar equator, and their area is about half that of those seen in November. However, the active area of AR3917 is slowly getting larger and with it the likelihood of a larger flare is increasing.

The Earth's ionosphere has been repeatedly affected in recent days by increased concentrations of solar-origin free electrons, which, while causing a slight rise in MUF, have been more pronounced in the ionosphere, causing scattering and hence attenuation, which has had a negative effect on the longer shortwave bands.

More meteors are arriving at Earth these days.ÿ The swarm is called the Geminids and most meteors should arrive about December 14. Therefore we can observe more frequent occurrences of the sporadic E layer.ÿ In addition to the occurrences of stronger signals on the longer shortwave bands, propagation through ionospheric waveguides is more frequent.ÿ The sporadic layer may not only form one of the walls of the waveguide, but also enable its termination. Which is a good chance, for example, for QRP devotees.

Predicted solar flux is 165 on December 13 to 15, 160 and 165 December 16 and 17, 160 on December 18 and 19, then 175, 185, and 190 on December 20 to 22, 185 on December 23 and 24, 180 on December 25 and 26, and 180 on December 30 through January 2, 2025.

Predicted planetary A index is 5 on January 13 and 14, 8 on January 15 and 16, 5 on January 17 to 20, then 8 on January 29.

Flare blasts South Africa:ÿ https://bit.ly/3Do6nJJ[1]

STCE Newsletter Online version:

http://www.stce.be/newsletter/newsletter.php[2]

PDF version:

http://www.stce.be/newsletter/pdf/2024/STCEnews20241212.pdf[3]

Send your tips, reports, observations, questions and comments to k7ra@rrl.net[4].ÿ When reporting observations, don't forget to tell us which mode you were operating. ÿ

For more information concerning shortwave radio propagation, see http://www.arrl.org/propagation[5] and the ARRL Technical Information Service web page at http://arrl.org/propagation-of-rf-signals[6] .

ÿFor an explanation of numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere[7] .

An archive of past propagation bulletins is at

http://arrl.org/w1aw-bulletins-archive-propagation[8] .

More information and tutorials on propagation are at http://k9la.us/[9]

Check "Understanding Solar Indices" from September 2002 QST at https://bit.ly/3Rc8Njt[10] .

Instructions for starting or ending email subscriptions to ARRL bulletins are at http://arrl.org/bulletins[11] .

Sunspot numbers for December 5 through 11 2024 were 101, 103, 91, 103, 94, 125, 114, with a mean of 104.4.ÿ 10.7 cm flux was 174.6, 177.5, 182.5, 177.7 172.5, 171.9, and 160.5 with a mean of 170.9. Estimated planetary A indices were 4, 8, 11, 7, 6, 13, and 7, with a mean of 8.ÿ Middle latitude A Index was 3, 6, 9, 6, 6, 6, 10, and 5, with a mean of 7.3.ÿ ÿ


[1] https://bit.ly/3Do6nJJ
[2] http://www.stce.be/newsletter/newsletter.php
[3] http://www.stce.be/newsletter/pdf/2024/STCEnews20241212.pdf
[4] mailto:k7ra@rrl.net
[5] http://www.arrl.org/propagation
[6] http://arrl.org/propagation-of-rf-signals
[7] http://arrl.org/the-sun-the-earth-the-ionosphere
[8] http://arrl.org/w1aw-bulletins-archive-propagation
[9] http://k9la.us/
[10] https://bit.ly/3Rc8Njt
[11] http://arrl.org/bulletins

---
þ Synchronet þ Whiskey Lover's Amateur Radio BBS

12/20/2024

Excellent HF conditions greeted hams in the ARRL 10-Meter contest
last weekend. Recent indicators show a sudden shift to two digit
daily sunspot numbers from three, and although there is nothing
significant about 100, it makes one notice.

All daily sunspot numbers this week were 97 or less.

Perhaps this indicates a move off of solar maximum, or to a future
with a second maximum.

Solar activity was way, way down this week with an average daily
sunspot number at just 88.

Predicted solar flux is 175, 180, 180, 185 and 180 on December
20-24, 175 on December 25-26, 180 on December 27, 185 on December
28-29, 180 on December 30 through January 2, 2025, and 175 on
January 3-4, 170 on January 5-6, 160 on January 7-8, then 165, 179,
165, and 170 on January 9-12, 165 on January 13-14, 170 on January
15-16, 175 on January 17-18, 180 on January 19-23, and 185 on
January 24-25.

The forecast for Planetary A index shows a quiet 5 on December
20-22, 8 on December 23-24, and 5 on December 25 through January 4,
2025, then 15 and 8 on January 5-6, 5 on January 7-9, then 12, 10
and 8 on January 10-12, and 5 on January 13-31.

OK1HH does not seem to have a commentary this week.

The latest report from Dr. Tamitha Skov, WX6SWW:

https://youtu.be/wClI7PKn3K0[1]

Send your tips, reports, observations, questions, and comments to k7ra@arrl.net[2]. When reporting observations, don't forget to tell us
which mode you were operating.

For more information concerning shortwave radio propagation, see http://www.arrl.org/propagation[3] and the ARRL Technical Information
Service web page at, http://arrl.org/propagation-of-rf-signals[4]. For
an explanation of numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere[5] .

An archive of past propagation bulletins is at http://arrl.org/w1aw-bulletins-archive-propagation[6] . More good
information and tutorials on propagation are at http://k9la.us/[7] .

Also, check this article:

https://bit.ly/3Rc8Njt[8]

"Understanding Solar Indices" from September 2002 QST.

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bulletins are at http://arrl.org/bulletins[9] .

Sunspot numbers for December 12 through 18 2024 were 91, 82, 86, 97,
90, 88, and 82 with a mean of 88. 10.7 cm flux was 172, 163.7,
170.5, 172, 166.7, 170, and 173.5 with a mean of 169.8. Estimated
planetary A indices were 6, 4, 10, 12, 14, 29, and 15, with a mean
of 12.9. Middle latitude A Index was 4, 2, 8, 9, 11, 20, and 12,
with a mean of 9.4.

ÿ


[1] https://youtu.be/wClI7PKn3K0
[2] mailto:k7ra@arrl.net
[3] http://www.arrl.org/propagation
[4] http://arrl.org/propagation-of-rf-signals
[5] http://arrl.org/the-sun-the-earth-the-ionosphere
[6] http://arrl.org/w1aw-bulletins-archive-propagation
[7] http://k9la.us/
[8] https://bit.ly/3Rc8Njt
[9] http://arrl.org/bulletins

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