Tad Cook, K7RA, of Seattle, Washington, reports for this week’s ARRL Propagation Bulletin:
Sunspot numbers and solar flux increased this week (September 29 through October 5), as expected, with the solar cycle progressing toward a probable peak in the summer of 2025.
Average daily sunspot number increased from 105.1 to 111.4, and average daily 10.7-centimeter solar flux increased from 138.4 to 149.2.
Compare it to a year ago, when average daily sunspot number was just 59.4 and solar flux was 89.8.
Predicted solar flux is 158 and 156 on October 6 – 7; 154 on October 8 – 9; 152, 150, 148, and 140 on October 10 – 13; 130 on October 14 – 15; 135 on October 16 – 17; 140 on October 18; 145 on October 19 – 21; 150 on October 22 – 23; 145, 140, and 135 on October 24 – 26; 145 on October 27 – 28; 150 on October 29; 155 on October 30 – 31; 145 on November 1, and 135 on November 2 – 4.
Predicted planetary A index is 12, 14, 10, 12, and 8 on October 6 – 10; 5 on October 11 – 12; 8 on October 13 – 14; 10 on October 15 – 16; 8 on October 17 – 19; 12 on October 20 – 21; 8 on October 22 – 29; 20, 12, and 10 on October 30 through November 1, and 8 on November 2 – 10.
On October 2, www.spaceweather.com announced “a big dangerous sunspot,” AR3112, one of the biggest in years, had rotated over the sun’s eastern horizon. They predict this could produce 2 weeks of high solar activity.
For the latest from Space Weather Woman Dr. Tamitha Skov, WX6SWW, visit:
Sunspot numbers for
September 29 through October 5, 2022, were 56, 74, 100, 102, 144, 153, and
151, with a mean of 111.4. The 10.7-centimeter flux was 137.2, 137.1,
147.9, 153.9, 155.1, 152.4, and 161, with a mean of 149.2. Estimated planetary A
indices were 7, 13, 3, 12, 24, 16, and 14, with a mean of 12.7. Middle
latitude A index was 7, 12, 2, 9, 16, 13, and 11, with a mean of 10.
Send your tips, questions, or comments to k7ra@arrl.net.
A comprehensive K7RA Solar Update is posted Fridays on the ARRL website. For more information concerning radio propagation, visit the ARRL Technical Information Service, read “What the Numbers Mean…” and check out the Propagation Page of Carl Luetzelschwab, K9LA.
A propagation bulletin archive is available. For customizable propagation charts, visit the VOACAP Online for Ham Radio website.
Share your reports and observations.