Tad Cook, K7RA, Seattle, reports: Solar activity was way up this week, and it was reflected in on-air activity, especially on 10 meters. If only the ARRL 10-Meter Contest were held a week later! The average daily sunspot number jumped by 100 points — from 24.4 last week to 124.4 in the December 16 – 22 reporting week. Average daily solar flux increased from 82.9 to 125.

Average planetary A index went from 5 to 9.1, and average middle latitude A index from 3.9 to 6.4.

It was great to see online images of the sun covered with spots.

Predicted solar flux over the next week looks quite promising, with daily solar flux more than 100 until the end of the year, then rising above 100 on January 16 – 22. But the outlook issued on Thursday, December 23 wasn’t as optimistic as the one issued a day earlier.

Flux values are predicted at 130, 125, 120, 115, and 113 on December 24 – 28; 110 on December 29 – 30; 85 on December 31; then 83, 81, 80, and 81 on January 1 – 4; 82 on January 5 – 6; 83, 86, 90, and 92 on January 7 – 10; 95 on January 11 – 12; 96 on January 13 – 15, jumping up to 115 on January 16 – 17; 114, 111, and 110 on January 18 – 20; 108, 102, and 95 on January 21 – 23; 90, 88, 87, and 85 on January 24 – 27, then dropping to a low of 80 on January 30 before rising above 90 after the first week of February.

Predicted planetary A index is 20, 12, 16, 8, 10, and 12 on December 24 – 29; 8 on December 30 – 31, then 5 on January 1 – 8; 8 and 5 on January 9 – 10; 10 on January 11 – 12; 5 on January 13 – 14; 8, 12, 18, 12, and 8 on January 15 – 19; 5 on January 20 – 22; 8, 10, 8, and 8 on January 23 – 26, and 5 on January 27 – February 4.

These observations from J.K. Janda, OK1HH:

“Unlike meteorologists, for example, we do not have reliable models of the Sun’s behavior and subsequent changes in Earth’s magnetosphere and atmosphere. Therefore, we did not expect the current increase in activity. On the other hand, we can consider them as another promise of a higher maximum of Solar Cycle 25.

“Most spots are in the Sun’s southern hemisphere, M-class flares are observed in both hemispheres, the solar flux has climbed from the lowest to the highest values in 2 weeks, and the solar wind speed increased over 10 days.

“Geomagnetic activity increased relatively only slightly, but only after the spot activity moved to the western half of the solar disk. These changes were mostly favorable for HF propagation conditions. Before the start of the ascent, the 18 MHz band was regularly open for DX contacts, while more recently, the 21 MHz band has opened relatively reliably.

“As a result of the eruptions of previous days, Earth’s magnetic field activity should increase around December 24 and likely again on December 27.

“Before the end of the year, a significant increase in solar activity is expected before it rises again around mid-January.”

Thanks to KH6CP for this article on the new WindCube satellite:

W9NY wrote from Chicago:

“Even though conditions were disappointing for most of the ARRL 10-Meter Contest weekend, there were sporadic openings all over the United States from my Dune Acres location, and for a few minutes at a time signals, from both the Colorado and California areas were very strong. I also worked a number of stations in South America, but only Puerto Rico in the Caribbean.

“On Sunday, 12/19, 10 really opened up for a while. I first heard a W6 beacon in the morning coming in S-9 and not another signal on the band. After one CQ at 28.420, I started a long string of contacts in late morning, and again during mid-afternoon. Some west coast stations running just 100 W to dipoles were coming in 20 dB over S-9, just like in the good old days.

“Made some contacts on 12 meters too. I heard nothing on 6 meters.

“I am looking forward to using my MFJ loop on 10 meters from Miami Beach over the first 3 months of 2022.”

KA3JAW monitors 11 meters for sporadic-E. On December 23 he wrote:

“Wednesday, December 22, saw a 6-hour multi-hop transatlantic sporadic-E event into western Europe on 11 meters, from 1326 to 1929 UTC. Solar flux index hit its highest point in the current solar cycle at 140. This was due to nine sunspot groups; 2907, 2908, 2909, 2911, 2912, 2915, 2916, 2917, and 2918.

“Sunday, December 19, saw a crazy 8-hour single and multi-hop sporadic-E day on 11 meters, from 1623 on December 19 until 0037 on December 20.

“During noontime, western Canadian prairie provinces plus US west coast stations were rolling into the US northeast. From 0222 until 2320 UTC, Es conditions were deteriorating with increased background noise conditions until the last station from Golden Valley, Arizona was heard at 0037 UTC. Seems that the secondary sporadic-E winter season has begun.”

On December 19, Steve Sacco (who did not give a call sign) wrote this, regarding 10 meters:

“I’ve never seen so many KL7s on at the same time. So far, have worked two, plus VE8CK and VY1FC.

“PSKR showing the band open from my location to Europe and KL7 and JA and VK at 2215 UTC on December 19. JA3REX worked at 2217 UTC.

“If only this had happened last weekend!”

Jon, N0JK, wrote:

“I was on 6 meters using MSK144 on the morning of December 14 at the peak of the Geminids meteor shower. 50.260 MHz was busy. Worked WI9WI, WG0G, and KF0Y in rare grid DN92 around 1400 UTC. All random contacts.

“Also checked 50.245 for W5A (EL15). Some flickers on the screen, but no decodes.”

W8TJM of Liberty Lake, Washington, commented on his December 19 activity on 15 meters:

“As soon as I got my 15 meter half-wave vertical antenna up at my low-noise site at 1915 UTC, I worked OH6RM in Finland. He was S-5 – S7 with very little QSB, and we had a solid 25-minute QSO, and then I listened to his contacts off and on for another hour. I also had an enjoyable contact with Per, SM2LIY, at 1950 UTC and he was also S-5 – S-7 but had a very fast flutter on his signal that was consistent. I heard no European stations.”

Carl, K9LA, commented:

“The paths that Toivo and Per commented on can be two different mechanisms depending on where the US station is. I wrote about this (called ‘the Santa Claus Polar Path‘) in my monthly column on my website back in 2014.

Space Weather Woman Tamitha Skov, WX6SWW, posted a new forecast on December 23 with a video running 96 minutes.

Sunspot numbers for December 16 – 22 were 127, 119, 117, 109, 115, 147, and 137, with a mean of 124.4. The 10.7-centimeter flux was 117.9, 120.9, 121.3, 115.3, 122.7, 136.6, and 140.4, with a mean of 125. Estimated planetary A indices were 8, 3, 4, 12, 16, 10, and 11, with a mean of 9.1. Middle latitude A index was 5, 2, 2, 8, 13, 7, and 8, with a mean of 6.4.

For more information concerning radio propagation, visit the ARRL Technical Information Service, read “What the Numbers Mean…,” and this propagation page by Carl Luetzelschwab, K9LA.

A propagation bulletin archive is available. For customizable propagation charts, visit the VOACAP Online for Ham Radio website.

Instructions for starting or ending email distribution of ARRL bulletins are on the ARRL website.

Share your reports and observations.