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.