Eight new sunspot groups emerged over this reporting week, January
4-10.

Four new sunspot groups appeared on January 5, another two on
January 7 and two more on January 9.

Average daily sunspot numbers rose from 63.4 to 146.1, and average
daily solar flux went from 141.9 to 163.3.

Geomagnetic indicators declined, with planetary A index going from
6.7 to 4.9, and middle latitude numbers from 5.1 to 4.3.

Predicted solar flux over the near term is 192, 190 and 186 on
January 12-14, 188 on January 15-16, then 186 and 184 on January
17-18, 150 on January 19-21, then 145 and 140 on January 22-23, 135
on January 24-26, then 130 and 135 on January 27-28, 140 on January
29-31, then 150, 160, 165 and 150 on February 1-4, 155 on February
5-6, 160 on February 7, then 155 on February 8-10, then 160, 165,
160 and 155 on February 11-14, and 150 on February 15-17.

Predicted planetary A index is 5 on January 12, 8 on January 13-14,
5, 5, 10 and 8 on January 15-18, 5 on January 19-27, 8 on January
28-30, 5 on January 31 through February 3, then 10, 10 and 8 on
February 4-6, and 5 on February 7-22.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth’s
Ionosphere – January 11, 2024 from OK1HH:

“Since the beginning of the 25th Solar Cycle (December 2019), we
observed 782 sunspot groups, and almost half of them (361) last
year. Most forecasters believe that the solar maximum will occur in
2024.

“The exception is the Bureau of Meteorology Australian Space Weather
Forecasting Centre, whose ‘OBSERVED AND PREDICTED SOLAR INDICES’ table, published on January 4, already showed the probable highest SMOOTHED SUNSPOT NUMBER = 126.4 last November.

“It should fall further until R = 15.5 in December 2029. But I
believe solar activity will continue to rise and that we have a
second maximum ahead of us, no later than 2025.

“Now there is usually at least one active region on the Sun with an
unstable magnetic field ‘beta-gamma,’ capable of producing flares of
moderate magnitude, possibly with CMEs.

“Any large flares would be the exception, and proton flares would be
even more of an exception.

“Among the more significant moderate-magnitude eruptions accompanied
by CMEs is the M3.8/2n class event of 4 January at 0155 UTC, which
produced the Dellinger event (SWF or Shortwave Fadeout) over
Australia and the surrounding Pacific Ocean. There was silence at
frequencies below 20 MHz for more than 30 minutes. This flare took
place in the northeastern solar disk (N04E39), while the CME missed
the Earth.

“Other developments on the Sun were quieter, which contributed to a
relatively long interval of geomagnetic quiet since 4 January
onwards. At the same time, the intensity of solar radiation
increased. The result was progressively improving shortwave
propagation. But seven major active regions can now be counted on
the Sun’s far side. Once they emerge onto the solar disk the
situation will change.”

NASA’s SDO reveals hidden solar storm threat to Earth:

https://bit.ly/3vxMJXU

Interesting application for use with Mobile Radio:

https://www.ve2dbe.com/

Send your tips, reports, observations, questions and comments to
k7ra@arrl.net. 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 and the ARRL Technical Information
Service web page at, http://arrl.org/propagation-of-rf-signals . For
an explanation of numbers used in this bulletin, see
http://arrl.org/the-sun-the-earth-the-ionosphere .

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

Also, check this page:

https://bit.ly/3Rc8Njt

Instructions for starting or ending email distribution of ARRL
bulletins are at http://arrl.org/bulletins .

Sunspot numbers for January 4 through 10 2024 were 64, 121, 149,
171, 152, 183, and 183, with a mean of 146.1. 10.7 cm flux was
125.8, 152.7, 159.4, 167.1, 176.2, 175.9, and 186, with a mean of
163.3. Estimated planetary A indices were 6, 5, 3, 3, 4, 6, and 7,
with a mean of 4.9. Middle latitude A index was 5, 4, 2, 3, 4, 5,
and 7, with a mean of 4.3.

Only four new sunspot groups emerged over the past week: one on December 28, 2023, another on December 31, and two more on January 2 and 3, 2024.

Solar indices sank. The average daily sunspot number declined from 114.4 to 63.4, and the average daily solar flux declined from 172.6 to 141.9.

Average daily planetary A index rose from 8.4 to 6.7, and middle latitude numbers rose from 4 to 5.1.

Predicted solar flux over the next few weeks looks moderate. It will be 145 on January 4 – 5; 150 on January 6 – 8; 155 on January 9; 160 on January 10 – 11; 155 on January 12 – 14; 160, 165, 160, and 155 on January 15 – 18; 150 on January 19 – 21; 145 and 140 on January 22 – 23, and 135 on January 24 – 26.

Predicted planetary A index is 8 on January 4; 5 on January 5 – 7; 10 on January 8 – 10, and 5 on January 11 – 26.

Solar activity looks soft as of late, but perhaps we will see a double peak during this cycle.

See an illustration comparing progress in the current cycle to the last cycle, month by month since each solar minimum, at: https://bit.ly/4aMBefh. The second chart from the top of the page is labeled “Solar Cycle Comparison.” The red line is the last cycle, and it was probably smoothed by monthly averages. The darker blue-green line is probably a conventional moving average with the points on the line smoothed over a year. The yellow line is the current cycle — also probably smoothed over a year — and the lighter blue-green line is the current cycle, which was probably smoothed with monthly numbers. This data looks promising for future activity.

Sunspot numbers for December 28, 2023, through January 3, 2024, were 83, 92, 48, 55, 44, 59, and 63, with a mean of 63.4. The 10.7-centimeter flux was 146.7, 142.9, 139.7, 146.2, 135.7, 142.1, and 140.2, with a mean of 141.9. Estimated planetary A indices were 3, 6, 5, 4, 10, 8, and 11, with a mean of 6.7. Middle latitude A index was 2, 6, 4, 2, 6, 8, and 8, with a mean of 5.1.

The recent reporting week, December 21-27, saw counter-intuitive solar numbers, with solar flux rising but sunspot numbers in decline. This happens from time to time.

Average daily sunspot numbers declined from 137.4 to 114.4. Only three new sunspot groups emerged, two on December 22, and one on December 27. On Thursday, December 28 one more sunspot emerged and the sunspot number increased from 78 to 83.

Average daily solar flux rose from 162.7 to 172.6.

Predicted solar flux over the next month is 145 on December 29-30, 140 on December 31 to January 1, 2024, 135 on January 2-4, 150 on January 5-7, 155 on January 8-11, then 150, 155, 160, 170 and 175 on January 12-16, 180 on January 17-21, then 170, 165, 162, 155 and 145 on January 22-26, then 140 on January 27-30, and 150 on January 31 to February 3.

Predicted planetary A index is 5, 10, 8, 16, and 8 on December 29 through January 2, 2024, then 5 on January 3-7, then 10, 10 and 8 on  January 8-10, then 5 on January 11-25, then 12, 10, 10 and 8 on January 26-29, and 5 on January 30 through February 3.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth’s Ionosphere, December 28, 2023 from F. K. Janda, OK1HH.

“There are active regions on the Sun that may not even be large, but whose magnetic configuration points to the possibility of solar flares, up to moderately important ones. CMEs are no exception, but they may not hit the Earth at all.

“On December 24, three moderate-importance flares were observed. At least one of them produced a CME. Based on measurements of its velocity, the collision with Earth was predicted to December 27. However, nothing happened, and despite the extension of the prediction of the onset of the disturbance by a day, calm continued on 28 December.

“For many days now there has been such a large active region on the Sun’s far side that it is affecting the vibration of the entire Sun. In addition, it has been observed by NASA’s Mars Perseverance rover camera. While it is primarily designed to see if there is dust in the air, it can see large sunspots and, most importantly, the sun’s far side is now visible from Mars.

“So we await the return of AR 3514, which will rise in the northeastern solar disk shortly after the New Year. It will be a significant contributor to the further rise in solar activity in the days ahead. Furthermore, longer term forecasts are calling for high solar activity in the second half of January. So perhaps we will finally see an improvement in shortwave conditions.”

Don’t forget ARRL Straight Key Night is this weekend, for all of New Years Day (UTC), so that starts at 4:00 PM Sunday here on the Left Coast where I live. Operate CW in a casual event using your straight key or semi-automatic bug.

Recent activity: https://bit.ly/3vhqLIE

Sun as revolving field motor: https://bit.ly/41CbEFA

Aurora: https://www.dailymotion.com/video/x8qwdc5

2023 solar activity:

http://tinyurl.com/55x96tfd   https://bit.ly/3RYngj1

Cosmic spectacle: https://bit.ly/41C8kdR

Larger storms: https://bit.ly/3RDl4fB

Tamitha Skov’s latest report: https://youtu.be/-xt-qMPQWwE

Send your tips, reports, observations, questions and comments to k7ra@arrl.net . 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  and the ARRL Technical Information Service web page at, http://arrl.org/propagation-of-rf-signals . For an explanation of numbers used in this bulletin, see

http://arrl.org/the-sun-the-earth-the-ionosphere

An archive of past propagation bulletins is at

http://arrl.org/w1aw-bulletins-archive-propagation . More good information and tutorials on propagation are at http://k9la.us/

Also, check this: https://bit.ly/3Rc8Njt

Instructions for starting or ending email distribution of ARRL bulletins are at http://arrl.org/bulletins

Sunspot numbers for December 21 through 27, 2023 were 138, 157, 123, 113, 98, 94, and 78, with a mean of 114.4. 10.7 cm flux was 193.6, 186.7, 174.2, 183.4, 166.7, 154.2, and 149.4, with a mean of 172.6. Estimated planetary A indices were 5, 4, 7, 9, 4, 5, and 4, with a mean of 5.4. Middle latitude A index was 3, 3, 5, 7, 2, 4, and 4, with a mean of 4.

There will be no informational net on Sunday December 24, 2023 and Dec 31, 2023 due to the holidays. See you again on Jan. 7 2024.

The winter solstice (the shortest day of the year in the Northern Hemisphere) will occur at 0327 UTC on December 22, 2023. This also marks the start of the summer solstice in the Southern Hemisphere.

Solar activity increased over the last reporting week of December 14 – 20 with 11 new sunspot groups emerging.

One new sunspot group appeared on December 15, four more on the following day, another on December 17, three more on December 18, and two more on December 19 – 20.

The average daily sunspot number rose from 110.3 to 137.4, and the solar flux rose from 129.8 to 162.7. The planetary A index increased from 5.6 to 18.4, and the middle latitude A index grew from 4.6 to 13.7.

The most active day was Sunday, December 17, when the planetary A index was 36, and Alaska’s college A index was 88. Spaceweather.com reported the cause was from the strongest flare of the current solar cycle, an X2.8 class, and it caused a radio blackout.

You can watch a video of the brief flash at https://bit.ly/3RP3xCw.

Spaceweather.com also reported that another flare is coming from sunspot group AR3529. Watch the movie they supplied at https://bit.ly/3tipAbr.

Predicted solar flux is 190, 188, and 186 on December 21 – 23; 182, 180, 170, and 165 on December 24 – 27; 145 on December 28 – 30; 150 on December 31; 145, 140, and 138 on January 1 – 3, 2024; 136 on January 4 – 5; 140, 145, and 148 on January 6 – 8; 145 on January 9 – 12, and 150, 147, 145, and 140 on January 13 – 16.

Predicted planetary A index is 10, 5, 12, and 8 on December 21 – 24; 5 on December 25 – 29; 8 on December 30 – 31; 10 and 8 on January 1 – 2, 2024; 5 on January 3 – 7; 10 on January 8 – 9; 8 on January 10; 5 on January 11 – 13; 15 on January 14; 12 on January 15 – 16, and 8 on January 17 – 19.

Watch Dr. Tamitha Skov’s, WX6SWW, new video from earlier this week at https://bit.ly/3GPRYET.

Read about big solar flares at https://bit.ly/3RQG4Rb, https://bit.ly/3RRzBpe, and https://bit.ly/48tJtuH.

Read about a temporary radio-signal blackout at https://bit.ly/3v5b5Il.

Sunspot numbers for December 14 – 20, were 126, 130, 163, 129, 137, 144, and 133, with a mean of 137.4. The 10.7-centimeter flux was 155.1, 144.3, 149, 154.6, 161.4, 179.3, and 195.3, with a mean of 162.7. Estimated planetary A indices were 16, 12, 14, 36, 28, 12, and 11, with a mean of 18.4. The middle latitude A index was 13, 8, 10, 32, 16, 10, and 7, with a mean of 13.7.

Solar activity declined this week. The average daily sunspot number dropped from 121.1 to 110.3, and the average daily solar flux decreased from 146.5 to 129.8.

Six new sunspot groups appeared this week. The first two appeared on December 8, another two appeared on December 11 and 12, and two more appeared on December 13.

Geomagnetic conditions were quieter, with the planetary A index dropping from 14.1 to 5.6, and the middle latitude numbers decreasing from 7.3 to 4.6.

Predicted solar flux shows some expected improvement, with values peaking at 160 on December 20 – 21 and 155 on January 23.

Predicted solar flux is 135 on December 14 – 16; 145, 150, and 155 on December 17 – 19; 160 on December 20 – 21, and then it drops back to 135 on December 22. It will be 140 on December 23 – 24; 150 on December 25 – 26; 155, 150, and 145 on December 27 – 29; 140 on December 30 through January 2, 2024, and 135 on January 3 – 5.

Predicted planetary A index is 8, 18, and 22 on December 14 – 16; 12 on December 17 – 18; 18, 8, 8, 20, and 10 on December 19 – 23; 5 on December 24 – 29; 8 on December 30 – 31; 10 and 8 on January 1 – 2, 2024, and 5 on January 3 – 6.

Reader David Moore shared an article about agencies collaborating on space weather projects. You can read it at https://bit.ly/46ZKDNF.

On Wednesday morning, Spaceweather.com announced:

“The best meteor shower of the year peak[ed] on December 13 – 14 with no moon to spoil the show. Rural observers could see hundreds of Geminid meteors and more than a few fireballs.”

Did you know that India has a solar observatory in space? Read about it at https://bit.ly/3GGecsH.

Watch Tamitha Skov’s new video from this week about the solar storm forecast at https://youtu.be/64CTIrWBGTc.

A couple of interesting QRZ.com pages to check out are KS7ROH‘s for his astrophotography and other projects, and W6BSD‘s for links to his propagation pages.

Sunspot numbers for December 7 through 13, 2023, were 121, 125, 125, 120, 87, 80, and 114, with a mean of 110.3. The 10.7-centimeter flux was 134.6, 132.6, 127.9, 126.6, 125.9, 126.2, and 134.8, with a mean of 129.8. Estimated planetary A indices were 5, 5, 3, 4, 3, 10, and 8, with a mean of 5.6. Middle latitude A index was 4, 4, 2, 4, 3, 8, and 7, with a mean of 4.6.

Six new sunspot groups emerged over this reporting week, November 30 to December 6, 2023.

Using the previous week’s bulletin as a template, last week’s averages were not updated, although all the correct data was there. This week’s bulletin includes the updated averages from last week.

Instead of 83.3 being the average daily sunspot number, it was actually 165.9, which dropped this week to 121.1.

Instead of an average daily solar flux of 146, it was actually 181.5, which declined this week to 146.5.

Instead of the average daily planetary A index of 10.1, it was actually 11.6, which rose this week to 17.1. Instead of the average middle latitude A index of 7.3, it was 9, which rose this week to 11.4.

Predicted solar flux is 130, 135, 135, and 140 on December 7 – 10; 130 on December 11 – 13; 140 on December 14 – 16; 150 on December 17; 160 on December 18 – 26; 155, 150, 145, and 140 on December 27 – 30; 136, 134, and 130 on December 31 through January 2, 2024, and 132 on January 3 – 5.

Predicted planetary A index is 8 on December 7; 5 on December 8 – 10; 8 on December 11 – 12; 5 on December 13 – 17; 15, 25, 8, 5, 20, and 10 on December 18 – 23; 5 on December 24 – 30; 25, 10, and 8 on December 31 through January 2, 2024, and 5 on January 3 – 6.

Read about a big hole in the sun at https://bit.ly/41adYDC and the sun’s new active region at https://bit.ly/3RxtCWG.

Don’t forget, the ARRL 10-Meter Contest is this weekend. Visit https://www.arrl.org/10-meter to learn more. Sunspot numbers for November 30 through December 6, 2023, were 138, 140, 92, 107, 113, 133, and 125, with a mean of 121.1. The 10.7-centimeter flux was 166.5, 162, 148.2, 139.2, 137.8, 141.6, and 129.9, with a mean of 146.5. Estimated planetary A indices were 5, 56, 14, 11, 9, 15, and 10, with a mean of 17.1. Middle latitude A index was 4, 30, 11, 10, 9, 9, and 7, with a mean of 7.3.

The Australian Space Weather Forecasting Centre issued the following Geomagnetic Disturbance Warning #23/74 at 2321 UT on November 29, 2023:

“Several coronal mass ejections (CMEs) are expected to impact Earth on November 30 and December 1, 2023. Two CMEs were observed on November 27 that were expected to arrive on November 30, followed shortly by a very mild, glancing blow from a third. One or possibly two halo CMEs were observed on November 29, which are Earth-directed. It is likely that all or some of these CMEs will combine on their trajectory toward Earth, making it difficult to pinpoint an exact arrival time. However, G3-G4 geomagnetic conditions are possible over this period.”

Over the past reporting week, 10 new sunspot groups appeared. There were three on November 23, one each day on November 24 – 26, another on November 28, and three more on November 29.

Solar numbers increased, with the average daily sunspot number rising dramatically from 83.3 to 165.9, doubling from the previous week.

The average daily solar flux rose from 146 to 181.5.

Geomagnetic numbers rose slightly, with the planetary A index changing from 10.1 to 11.6, and the middle latitude number changing from 7.3 to 7.6.

Predicted solar flux is 175 on November 30; 170 on December 1; 165 on December 2 – 3; 160 on December 4; 150 on December 5 – 6; 140 on December 7 – 8; 145 on December 9 – 10; 140 on December 11 – 16; 150 on December 17, and 160 on December 18 – 28.

Predicted planetary A index is 30, 56, and 22 on November 30 through December 2; 10, 10, 12, 10, and 10 on December 3 – 7; 5 on December 8 – 11; 10 and 8 on December 12 – 13; 5 on December 14 – 17; 15, 25, 8, and 5 on December 18 – 21, and 20, 10, 10, 8, and 5 on December 22 – 26.

Watch a new video from Dr. Tamitha Skov, WX6SWW, about solar storms at https://youtu.be/qiHtkXfZnQo. Sunspot numbers for November 23 – 29, 2023, were 176, 184, 179, 169, 159, 130, and 164, with a mean of 83.3. The 10.7-centimeter flux was 194.2, 178, 176.4, 180.2, 187.3, 183.5, and 170.6, with a mean of 146. Estimated planetary A indices were 7, 7, 38, 10, 7, 7, and 5, with a mean of 10.1. Middle latitude A index was 4, 5, 18, 9, 2, 6, and 9, with a mean of 7.3.

Because of the Thanksgiving holiday, this bulletin preview is moved back a day and does not have the full Thursday-through-Wednesday data; that will appear in Friday’s bulletin.

Last weekend, conditions during the ARRL November Phone Sweepstakes were great because geomagnetic activity was so low. Planetary A index was 3 and 4, and even high-latitude indicators were low. Alaska’s college A index was 2 and 1.

Solar activity has been up for the past few days. Starting on November 17, a new sunspot group appeared every day, and on Monday, November 20, six new sunspot groups emerged. Sunspot numbers on Monday and Tuesday were 127 and 138, which is the first time the daily sunspot number has been more than 100 since November 3.

Predicted solar flux is 172, 175, and 177 on November 22 – 24; 180 on November 25 – 27; 185 on November 28 – 29; 155 on November 30 – December 1; 150, 152, 148, and 145 on December 2 – 5; 140 on December 6 – 8; 145 on December 9 – 10, and 140 on December 11 – 17. Predicted planetary A index is 14, 12, and 8 on November 22 – 24; 5 on November 25 – 26; 10 and 8 on November 27 – 28; 5 on November 29 – December 3; 12, 16, 12, and 10 on December 4 – 7; 5 on December 8 – 11; 10 and 8 on December 12 – 13, and 5 on December 14 – 17.

Solar activity was lower this week, November 9 – 15, 2023, with the average daily sunspot numbers dropping from 89.7 to 80.1, and the average daily solar flux from 151.7 to 133.8.

If those numbers seem a little low lately, we should check the bulletin from the same week last year. In the November 18, 2022, bulletin, the average daily sunspot number changed from 79.8 to 72.3, so a year later we are definitely trending higher.

Geomagnetic indicators were also lower, with the planetary A index changing from 22.3 to 10.4, and the middle latitude A index from 14.6 to 8.6.

A single new sunspot group appeared on November 10, another on November 12, one more on November 13, and another on November 14.

The predicted solar flux is 120, 118, 116, 120, and 122 on November 16 – 20; 125 on November 21 – 22; 135 on November 23 – 25; 140, 148, and 152 November 26 – 28; 155 on November 29 through December 1; 152, 150, 148, and 145 on December 2 – 5; 140 on December 6 – 8; 145, 135, 130, and 125 on December 9 – 12, and 120 on December 13 – 15.

The predicted planetary A index is 10 and 8 on November 16 – 17; 5 on November 18 – 19; 8 on November 20 – 21; 5, 12, 18, 20, and 12 on November 22 – 26; 8 on November 27 – 28; 5 on November 29 through December 3; 10, 16, 12, and 10 on December 4 – 7; 5 on December 8 – 9; 8 on December 10 – 13, and 5 on December 14 – 18.

Check this site for an update of current conditions on various bands: https://dr2w.de/dx-propagation/ Sunspot numbers for November 9 – 15, 2023, were 93, 93, 85, 78, 85, 86, and 41, with a mean of 80.1. The 10.7-centimeter flux was 138.7, 143.9, 141.5, 137.2, 132.7, 123.8, and 118.9, with a mean of 133.8. Estimated planetary A indices were 12, 10, 5, 12, 16, 6, and 12, with a mean of 10.4. The middle latitude A index was 8, 7, 4, 10, 5, and 11, with a mean of 8.6.