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.

Solar activity bounced back this reporting week, September 8 – 14, when the average daily sunspot number jumped from 68 to 92.7, and the average solar flux from 125.8 to 141.3.

Fewer Coronal Mass Ejections (CMEs) and flares were evident, with the average planetary A index declining from 24.6 to 10.7, and the middle latitude numbers from 17.4 to 10.6.

New sunspot groups appeared: one on September 8, three on September 10, and one more on September 13. The total sunspot area (in millionths of a solar disc) on September 12 – 14 rose from 370 to 870 to 1240 — the highest value in over a month.

The sunspot number was highest on September 10 at 122.

During this week 2 years ago, there were no sunspots at all. The average daily solar flux was only 69.7, over 56 points lower than this week, demonstrating the continued progress of Cycle 25.

The latest (Wednesday) forecast from the space weather folks at Offutt Air Force Base shows predicted solar flux peaking at 150 on October 9, and flux values on September 15 at 140. Then 135 on September 16 – 18; 130 on September 19 – 21; 120 on September 22 – 29; 125 on September 30 through October 6; 130 on October 7 – 8; 150, 148, 143, and 140 on October 9 – 12; 136, 130, 125, and 120 on October 13 – 16, and 125 on October 17.

Predicted planetary A index shows moderate levels of geomagnetic activity until October 1 – 2. The forecast is 5, 15, 18, and 12 on September 15 – 18; 5 on September 19 – 22; 12 and 10 on September 23 – 24; 14 on September 25 – 27; 8 on September 28 – 29; 22, 50, 40, 20, and 12 on September 30 through October 4; 15, 12, 10, 8, and 5 on October 5 – 9; 10, 8, 5, 15, 20, and 12 on October 10 – 15, and 5 on October 16 – 19.

Below is a nice solar video from last month:

https://bit.ly/3BH9ZDm

Here is NOAA’s latest forecast discussion:

https://www.swpc.noaa.gov/products/forecast-discussion

Sunspot numbers for September 8 – 14 were 75, 72, 122, 113, 117, 93, and 57, with a mean of 92.7. The 10.7-centimeter flux was 126.6, 126.2, 135.9, 151.5, 150.4, 154.1, and 144.3, with a mean of 141.3. Estimated planetary A indices were 19, 13, 12, 9, 9, 4, and 9, with a mean of 10.7. The middle latitude A index was 17, 14, 10, 9, 9, 5, and 10, with a mean of 10.6.

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

Share your reports and observations.

This week, September 1 – 7, 2022, two new sunspot groups emerged on September 1, two more on September 2, one more on September 5, another on September 6, and one more on September 7.

But average daily sunspot numbers declined from 74.9 to 68, while average daily solar flux rose from 123.8 to 125.8.

Geomagnetic indicators were way up, and the average daily planetary A index rose from 10.1 to 24.6, while middle latitude numbers increased from 9.4 to 17.4.

September 4 was the most active day, with the planetary A index being 64. On that day, the college A index in Fairbanks, Alaska, was 91!

Predicted solar flux is 125 on September 8 – 14; 126 on September 15; 125 on September 16 – 17; 126 and 120 on September 18 – 19; 125 on September 20 – 21; 115 on September 22 – 24; 120 on September 25 – 28; 118 on September 29 – 30; 115 and 125 on October 1 – 2; 120 on October 3 – 4; 122 on October 5; 120 on October 6 – 7; and 125 on October 8 – 11.

Predicted planetary A index is 50 on October 1! Otherwise, 10 on September 8; 8 on September 9 – 11; 5 on September 12; 20 on September 13 – 14; 10 on September 15; 8 on September 16 – 17; 5 on September 18 – 22; 12 and 10 on September 23 – 24; 14 on September 25 – 27; 8 on September 28 – 29; 22, 50, 25, 16, 12, and 10 on September 30 through October 5; 8 on October 6 – 8, and 5, 12, and 15 on October 9 – 11.

Sunspot numbers for September 1 through 7 were 67, 71, 68, 62, 79, 56, and 73, with a mean of 68. The 10.7-centimeter flux was 116.3, 129.8, 123.4, 128.3, 130.2, 126.2, and 126.1, with a mean of 125.8. Estimated planetary A indices were 9, 8, 25, 64, 32, 20, and 14, with a mean of 24.6. Middle latitude A index was 9, 10, 23, 33, 21, 14, and 12, with a mean of 17.4.

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.

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

A new sunspot group emerged on August 18 and August 21, and two more emerged on August 23. Overall, solar activity was down slightly, with the average daily sunspot number declining from 60.8 to 58.7, and average solar flux from 123.7 to 104.5.

Planetary A index changed from an average of 11.7 to 12.6, and middle latitude A index, measured at a single magnetometer in Virginia, was 11, after an average of 10 last week.

The Wednesday night forecast from the 557^th Weather Wing at Offutt Air Force Base showed a probable solar flux peak at 130 on September 11 for the near term.

Predicted solar flux is 105 on August 25 – 26; 108 on August 27 – 28; 110 on August 29 through September 1; 114 on September 2; 116 on September 3 – 4; 112 on September 5; 108 on September 6 – 7; 115, 120, 124, and 130 on September 8 – 11; 128, 120, 118, 105, and 102 on September 12 – 16; 98 on September 17 – 18; 96 on September 19 – 21; 94 on September 22 – 24, and 92, 98, and 100 on September 25 – 27.

Predicted planetary A index has some surprises in store: 5 on August 25 – 26; 8 on August 27 – 28; 5 on August 29 through September 2; then jumping way up to 30, 38, and 20 on September 3 – 5; 15, 18, 10, 12, and 8 on September 6 – 10; 5 on September 11 – 12; 12, 15, and 10 on September 13 – 15; 8 on September 16 – 17; 25, 15, and 8 on September 18 – 20; 5 on September 21 – 22; 12 on September 23, and 8 on September 24 – 26.

My main power supply failed on August 21, so for a week or two I will be unable to make on-the-air observations as I await factory repair.

News about a large sunspot can be found at https://inshorts.com/en/news/huge-sunspot-on-suns-surface-grows-10-times-in-size-in-48-hours-pic-surfaces-1661347322422.

Sunspot numbers for August 18 through 24 were 83, 74, 56, 56, 44, 52, and 46, with a mean of 58.7. The 10.7-centimeter flux was 116.5, 105.4, 101.5, 97, 102.6, 100.9, and 107.8, with a mean of 104.5. Estimated planetary A indices were 26, 20, 14, 14, 7, 4, and 3, with a mean of 12.6. Middle latitude A index was 19, 15, 16, 13, 7, 3, and 4, with a mean of 11.

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:

At 2334 UTC on August 17, the Australian Space Forecast Centre issued a geomagnetic disturbance warning.

“Periods of G1 conditions expected during August 19 – 20 due to the combination of coronal hole high — speed wind stream and several coronal mass ejections observed in the last few days. There is a chance of isolated periods of G2 over August 19 – 20.”

Local TV newscasts in Seattle noted the possibility of an aurora on Thursday night, although observers would need to travel to dark areas away from the city for any chance of successful viewing. In fact, they recommended using a camera pointed north using a long exposure time.

Last week, we noted increasing solar activity, and it continued. Average daily sunspot numbers increased from 65.4 to 95.6, and average daily solar flux increased from 111.9 to 123.7.

Predicted solar flux is 125 on August 18 – 19; 120 on August 20; 115 on August 21 – 23; 110 and 95 on August 24 – 25; 94 on August 26 – 27; 96, 98, 100, 108, and 114 on August 28 – September 1; 116 on September 2 – 3; 112 on September 4; 108 on September 5 – 6; 115, 120, 124, and 126 on September 7 – 10; 124 on September 11 – 12; 122, 118, 112, 108, and 102 on September 13 – 17, and 100 on September 18 – 19.

Predicted planetary A index is 56 (!), 30, 18, and 8 on August 18 – 21; 5 on August 22 – 26; 12 on August 27; 8 on August 28 – 30; 5 on August 31 – September 2; 24, 28, 18, and 10 on September 3 – 6; 14, 8, 10, and 8 on September 7 – 10; 5, 5, 20, and 15 on September 11 – 14; 12, 12, and 8 on September 15 – 17, and 5 on September 18 – 20.

Tamitha Skov says, “Don’t worry, this is not a Carrington Event,” in an 84-minute video titled, “Incoming Solar Storm Crush.”

Even Newsweek is reporting it.

And of course, British Tabloids

and NOAA.

Sunspot numbers for August 11 – 17, 2022, were 58, 97, 116, 104, 92, 119, and 83, with a mean of 95.6. The 10.7-centimeter flux was 114.8, 119.5, 124.2, 125.5, 130.6, 128.5, and 122.7, with a mean of 123.7. Estimated planetary A indices were 16, 7, 10, 7, 6, 5, and 31, with a mean of 11.7. Middle latitude A index was 12, 6, 10, 9, 6, 5, and 22, 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.

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

Solar activity continued to decline this week, with the average daily sunspot number dropping from 91.1 to 36.6, and average solar flux at 95.7, down from 107.6 the week prior.

We have not seen lower values since mid-April in bulletin ARLP015

with average sunspot number at 34.4, and the end of February in ARLP008 with the average solar flux at 95.4.

This was noticeable over the past week on 10 and 12 meters, but there must still be some daily sporadic E, from what I have seen on an email list devoted to 10-meter propagation beacons. I have one myself — K7RA/B transmitting CW from CN87uq on 28.2833 MHz.

The outlook from the United States Air Force space weather group shows a meager forecast for solar flux, according to forecasters Sadovsky and Ciopastu on Wednesday.

Predicted solar flux over the next month never rises above 100, having values of 100 for August 4 – 7; 98 and 96 on August 8 – 9; 98 on August 10 – 14; 100 on August 15 – 16; 98 on August 17 – 18; 96, 96, and 98 on August 19 – 21; 96 again on August 22 – 23; 92 on August 24 – 28; 90 and 92 on August 29 – 30; 94 on August 31 – September 1; 96 on September 2 – 3, and 98 on September 4 – 10.

Predicted planetary A index is 8 on August 4; 5 on August 5 – 7; 8, 14, and 12 on August 8 – 10; 8 on August 11 – 12; 5 on August 13 – 16; 22 on August 17; 15 on August 18 – 19; 8 on August 20 – 21; 5 on August 22 – 25; 10 and 12 on August 26 – 27; 5 on August 28 – 29; 12 and 10 on August 30 – 31, and 5 on September 1 – 6.

Sunspot numbers for July 28 – August 3 were 50, 40, 27, 39, 32, 31, and 37, with a mean of 36.6. The 10.7-centimeter flux was 93, 90.8, 94.3, 95.4, 97.8, 98.8, and 99.9, with a mean of 95.7. Estimated planetary A indices were 7, 4, 7, 11, 8, 9, and 8, with a mean of 7.7. Middle latitude A index was 9, 6, 8, 12, 8, 10, and 7, with a mean of 8.6.

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