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.