Tad Cook, K7RA, of Seattle, Washington, reports for this week’s ARRL Propagation Bulletin:

Sunspot activity took quite a plunge over this reporting week (October 13 – 19). Average daily sunspot numbers declined from 114.9 to 57.3, while equivalent solar flux values went from 155.3 to 119.6.

Geomagnetic indicators were slightly lower, with the average planetary A index going from 13.3 to 10.6, and middle latitude A index from 10.4 to 8.1.

I should note that the middle latitude A index for October 18 – 19 are my own estimates. The Fredericksburg, Virginia, magnetometer was offline for a 24-hour period spanning both days.

The Wednesday forecast of solar flux shows a peak at 160 during the first week in November.

Predicted daily flux values are 110 on October 20 – 26; 115 and 150 on October 27 – 28; 155 on October 29 – 30; 152 on October 31; 160 on November 1 – 8; 150, 140, and 135 on November 9 – 11; 130 on November 12 – 13; 135 on November 14; 138 on November 15 – 17, and 140 on November 18 – 21.

Predicted planetary A index is 12 and 10 on October 20 – 21; 5 on October 22 – 23; 10, 5, 8, and 12 on October 24 – 27; 15, 12, and 20 on October 28 – 30; 15 on October 31 through November 1; 18, 15, 12, 20, and 8 on November 2 – 6; 5 on November 7 – 9; 18 on November 10 – 11; 15 and 8 on November 12 – 13; 5 on November 14 – 15; 12 on November 16 – 17; 8 on November 18, and 5 on November 19 – 21.

Despite the lower solar activity, worldwide 10-meter propagation has been very good this week, probably helped by seasonal variations as we head deeper into the fall season.

In Friday’s bulletin, expect reports from readers.

Sunspot numbers for October 13 through 19 were 57, 51, 50, 59, 84, 50, and 50, with a mean of 114.9. The 10.7-centimeter flux was 130, 120.5, 115.1, 119.2, 125.6, 113.9, and 113.2, with a mean of 155.3. Estimated planetary A indices were 5, 18, 18, 16, 6, 6, and 5, with a mean of 13.3. Middle latitude A index was 4, 16, 15, 11, 4, 4, and 3, with a mean of 10.4.

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.

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.

The proposed date for the startup of the Sunday night informational net will be Sunday November 6, 2022 @ 8:00 pm. Keep checking here on the web site for any additional information that may came up.

Tad Cook, K7RA, of Seattle, Washington, reports for this week’s ARRL Propagation Bulletin:

Sunspot activity rose this week, as the average daily sunspot numbers increased from 68 to 105.1.

But solar flux? Not so much. The average daily solar flux rose from 134.3 to 138.4.

So, the sunspot average rose 55% and solar flux rose only 3%. We usually expect the numbers to track closer.

Tuesday, September 27, had lots of geomagnetic activity, with the planetary A index at 24 and middle latitude at 33. At www.spaceweather.com, blamed an unexpected CME for this activity. They also reported a huge sunspot beyond the sun’s eastern horizon and a helioseismic image at https://bit.ly/3ftpTIN.

The Australian Space Weather Forecasting Centre issued a geomagnetic warning at 2146 UTC on September 28, stating, “Geomagnetic 27-day recurrence patterns indicate that G1 geomagnetic activity is likely during the interval between September 30 and October 2. INCREASED GEOMAGNETIC ACTIVITY EXPECTED DUE TO CORONAL HOLE HIGH SPEED WIND STREAM.”

Predicted solar flux is 135 on September 29; 130 on September 30 through October 1; 125 on October 2 – 3; 120 on October 4 – 5; 132 on October 6 – 7; 135, 130, 128, and 132 on October 8 – 11; 136 on October 12 – 13; 138, 140, 138, and 135 on October 14 – 17; 132, 130, 128, and 125 on October 18 – 21; 130, 140, 142, and 145 on October 22 – 25, and 140, 135, 130, 125, 128, and 130 on October 26 – 31.

Planetary A index is predicted at 8, 20, 60, and 40 on September 29 through October 2; 20, 18, 16, and 10 on October 3 – 6; 8 on October 7 – 14; 10 on October 15 – 16; 8 on October 17 – 19; 12 on October 20 – 21; 8 on October 22 – 23; 10 on October 24 – 25, and 8 on October 26 – 27. Then, in a recurrent disturbance as the sun rotates into the same position as weeks earlier, 25, 50, 30, 20, 12, and 10 on October 28 through November 2.

Sunspot numbers for September 22 through 28, were 99, 111, 128, 96, 120, 110, and 72, with a mean of 105.1. The 10.7-centimeter flux was 136.7, 146.3, 146.5, 134.7, 135.1, 134.5, and 134.8, with a mean of 138.4. Estimated planetary A indices were 6, 12, 13, 7, 6, 24, and 5, with a mean of 10.4. Middle latitude A index was 5, 12, 10, 5, 5, 33, and 3, with a mean of 10.4.

Send your tips, questions, or comments to k7ra@arrl.net.

Tad Cook, K7RA, of Seattle, Washington, reports for this week’s ARRL Propagation Bulletin:

Geomagnetic disturbances were down this week, but so were sunspot numbers and solar flux.

Average daily sunspot numbers declined from 92.7 to 68, and average daily solar flux declined from 141.3 to 134.3.

Six new sunspot groups appeared this week, the first on September 15, two more on September 19, another on September 20, and two more on September 21.

Predicted solar flux is 140 and 138 on September 22 – 23; 130 on September 24 – 27; 120 on September 28; 122 on September 29 through October 2; 120 again on October 3; 122 on October 4 – 7; 125, 122, and 120 on October 8 – 10; 118 on October 11 – 12; 116 on October 13 – 15; 138 on October 16; 135 on October 17 – 18, and 133, 128, 126, 130, and 125 on October 19 – 23.

Predicted planetary A index is 10 and 20 on September 22 – 23; 15 on September 24 – 25; 8 on September 26 – 29; 22, 50, 30, and 20 on September 30 through October 3; 12, 15, 12, and 10 on October 4 – 7; 8, 8, 5, and 8 on October 8 – 11; 5 on October 12 – 14; 12, 10, 5, 5, 20, 18, and 12 on October 15 – 21, and 8 on October 22 – 26.

The above predictions were made by the Offutt Air Force Base.

For information on whether sunspots are really black, visit www.livescience.com/why-are-sunspots-black.

I’m pleased to report that the 2022 Autumnal Equinox is Friday, September 23, at 0104 UTC. Both the Northern and Southern Hemispheres will be bathed in equal measures of solar radiation, which is good for HF propagation.

Sunspot numbers for September 15 through 21 were 71, 64, 76, 51, 74, 70, and 70, with a mean of 68. The 10.7-centimeter flux was 139.7, 131.1, 131.5, 136.1, 127.9, 137.2, and 136.9, with a mean of 134.3. Estimated planetary A indices were 6, 4, 5, 11, 11, 8, and 5, with a mean of 7.1. Middle latitude A index was 8, 5, 5, 9, 7, 6, and 4, with a mean of 6.9.

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.