Tad Cook, K7RA, Seattle, reports: Solar activity has declined, with the weekly average daily sunspot number slipping from 57.6 last reporting week to 17.4 over the past week.

Solar flux averages also slipped over the past 2 weeks from 108.1 to 91.9 and to 82.1 over the most recent week. The latest solar flux prediction also appears soft. Solar flux is expected to peak at 86 on December 26-28, hit a low at 82 on January 1-10, and then peak again at 86 on January 21-24.

Predicted values over the next 45 days are 82 on December 18 – 24; 83 on December 25; 86 on December 26 – 28; 85, 84, and 83 on December 29 – 31; 82 on January 1 – January 10; 83, 83, and 84 on January 11 – 13; 85 on January 14 – 20; 86 on January 21 – 24; 85, 84, and 83 on January 25 – 27, and 82 on January 28 – 31.

Predicted planetary A index is 5 on December 18 – 20; 12 on December 21; 8 on December 22 – 25; 5 on December 26 – January 4; 10 on January 5 – 6; 5 on January 7 – 12; 8 on January 13; 5 on January 14 – 16; 10, 12, and 10 on January 17 – 19; 8 on January 20 – 21, and 5 on January 22 – 31.

Here’s the geomagnetic activity forecast for December 18 – January 12, 2021 from F.K. Janda, OK1HH. The geomagnetic field will be:

• quiet on December 28, January 4, 12

• quiet to unsettled on December 23, 29, 31, January 1, 3 – 4

• quiet to active on December 18, 24 – 27, 30, January 6, 8, 10 – 11

• unsettled to active December 19, 22, January 2, 5, 7, 9

• active to disturbed December 20 – 21

• Solar wind will intensify on December (20,) 21 ( – 23, 25,) 27 (28 – 29,) (January 1 – 3, 7 – 8)

Parentheses mean lower probability of activity enhancement.

I noticed after the ARRL 10-Meter Contest last weekend that K7RL had claimed an impressive score of 379,680. Checking his QRZ.com profile, I saw that he’s not only surrounded by salt water on an island in Puget Sound but has an amazing collection of steel and aluminum in the air. He commented to the Western Washington DX Club email list:

“That was much more fun than expected. Every contest has that moment when an interesting mult calls in, or you hit a great opening. My moment was being called by ZD7BG on SSB.

“When the big openings hit both days, you had to be ready to step on the gas and run like crazy because it could end just as quickly. There was always some activity, it was mostly a matter of volume and signal strength. Some signals lasted seconds, if even that, while others were there almost all weekend like KV0Q and K0RF.”

Another impressive effort, but on a much different scale, was K6ARK’s solo SOTA operation.

The National Science Foundation has published an article, “New sunspot cycle could be one of the strongest on record.”

An article in Otago Daily Times celebrated the return of sunspots in New Zealand.

Sunspot numbers for December 10 – 16 were 11, 11, 24, 14, 25, 25, and 12, with a mean of 17.4. The 10.7-centimeter flux was 81.5, 83.3, 81.8, 80.6, 83, 82.9, and 81.9, with a mean of 82.1. Estimated planetary A indices were 8, 7, 4, 5, 3, 3, and 3, with a mean of 4.7. Middle latitude A index was 6, 4, 3, 3, 2, 2, and 3, with a mean of 3.3.

For more information concerning radio propagation, visit the ARRL Technical Information Service, read “What the Numbers Mean…,” and check out K9LA’s Propagation Page.

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.

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