Average daily sunspot numbers declined from 130.6 to 128.1 over the past week of July 20 – 26.

Average daily solar flux declined significantly from 190.5 to 172.2.

The solar flux forecast sees values at 168, 165, and 162 on July 27 – 29; 158 on July 30 – 31; 155 and 158 on August 1 – 2; 165 on August 3 – 4; 170 and 175 on August 5 – 6; 180 on August 7 – 10; 175 on August 11 – 13; 180 on August 14 – 15; 175 on August 16 – 18; 170 on August 19; 165, 165, and 160 on August 20 – 22, and 155 on August 23 – 26.

Predicted planetary A index is 20, 10, 5, 10, and 8 on July 27 – 31; 5, 5, 10, and 8 on August 1 – 4; 5 on August 5 – 9; 10 on August 10; 8 on August 11 – 13; 5 on August 14 – 19, and 10, 8, and 5 on August 20 – 22.

Read about sunspots, flares, and aurora at the following link:

https://bit.ly/44JxcRp

Check out a story about the Mars rover seeing the far side of the sun at the link below:

https://bit.ly/3KbRV8b

Also, see the report of a rocket punching a hole in the ionosphere at:

https://bit.ly/3KceBFB

Nearly 5 decades ago in Marin County, California, I, too, witnessed a rocket penetrating the ionosphere. It was a huge, dramatic display. My friend had seen a similar thing before, and said it was created by a rocket launch from Vandenberg Air Force Base in Southern California.

Sunspot numbers for July 20 – 26, 2023, were 131, 121, 103, 117, 141, 137, and 147, with a mean of 128.1. The 10.7-centimeter flux was 184.3, 172.8, 174.4, 172.5, 165.1, 169, and 167.4, with a mean of 172.2. Estimated planetary A indices were 10, 13, 9, 6, 7, 11, and 21, with a mean of 11. Middle latitude A index was 10, 11, 9, 5, 8, 12, and 23, with a mean of 11.1.

Average daily sunspot numbers declined, but the average daily solar flux increased. Sunspot averages were 181.9 last week and 130.6 this week. The average daily solar flux increased from 179.4 to 190.5.

Two new sunspot groups emerged on July 14, as well as three more on July 17, and another two on July 19.

The average daily planetary and middle latitude A indices were both 12.9 this week, rising from 8.6 and 8.1.

Predicted solar flux is 188 on July 20 – 23; 186, 184, 186, and 160 on July 24 – 27; 165 on July 28 – 29; 170 on July 30 – 31; 165 on August 1 – 4; 170, 175, 175, and 170 on August 5 – 8; 165 on August 9 – 11; 170 on August 12; 175 on August 13 – 14, and 170 on August 15 – 19.

The predicted planetary A index is 28, 20, and 12 on July 20 – 22; 5 on July 23 through August 2; 10 and 8 on August 3 – 4; 5 on August 5 – 14, then 12, 8, and 8 on August 15 – 17.

CNN presented a smart piece on the sunspot cycle peaking sooner than expected:

https://bit.ly/3rzNJJ6

Cosmos published an article about a double-peaked solar flare:

https://bit.ly/46ZoznE

Sunspot numbers for July 13 – 19, 2023, were 146, 141, 96, 99, 149, 142, and 141, with a mean of 130.6. The 10.7-centimeter flux was 202.9, 180.6, 178.5, 184.3, 180, 218.5, and 188.9, with a mean of 190.5. Estimated planetary A indices were 7, 20, 8, 10, 24, 16, and 5, with a mean of 12.9. Middle latitude A index was 9, 17, 9, 13, 19, 16, and 7, with a mean of 12.9.

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.

We saw a rise in solar activity this reporting week, July 6 – 12, 2023.

Referencing the previous 7 days, average daily sunspot numbers rose from 126.1 to 181.9, while the average daily solar flux increased from 164.5 to 179.4.

Geomagnetic indicators did not change much. The average planetary A index went from 7.3 to 8.6 and the average daily middle latitude A index went from 8 to 8.1.

The most active day was July 7, when the University of Alaska’s College A index was 40! The middle latitude A index on that day was only 11. The College A index was measured by a magnetometer in Fairbanks, Alaska.

Predicted solar flux looks like it will be great over the next few days, at 190 on July 13; 188 on July 14 – 15; 186 on July 16; 182 on July 17 – 18; 180 on July 19; 170 on July 20 – 21; 160 on July 22 – 23; 155 on July 24 – 25; 160 on July 26 – 27; 165 on July 28 – 29; 170 on July 30 – 31; 165 on August 1 – 4; 170 on August 5; 175 on August 6 – 7; 170 on August 8, and 165 on August 9 – 11.

Predicted planetary A index is 15 and 10 on July 13 – 14; 5 on July 15 through August 2; 10, 8, and 5 on August 3 – 5, then 8, 8, 5, 8, and 8 on August 6 – 10.

On July 12, spaceweather.com reported:

“A new hyperactive sunspot is producing M-class solar flares every few hours. This is causing shortwave radio blackouts around all longitudes of our planet. If current trends continue, an X-flare could be in the offing.”

See spaceweather.com for updates.

Thanks to reader David Moore for sending us the information on aurora hype at https://bit.ly/44ovzsh. Sunspot numbers for July 6 through 12, 2023, were 149, 147, 167, 183, 181, 227, and 219, with a mean of 181.9. The 10.7-centimeter flux was 157.6, 161.4, 160.5, 179.2, 190.6, 213.5, and 193.3, with a mean of 179.4. Estimated planetary A indices were 11, 18, 8, 4, 5, 8, and 6, with a mean of 8.6. The middle latitude A index was 11, 16, 6, 4, 6, 8, and 6, with a mean of 8.1.

. 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.

According to Spaceweather.com, the average daily sunspot number for June 2023 was 163, which is the highest it’s been in 21 years.

From a July 3, 2023, email:

“The average sunspot number in June 2023 hit a 21-year high. Solar Cycle 25 has shot past its predecessor, Solar Cycle 24, and may be on pace to rival some of the stronger cycles of the 20th century.”

Could we see another Solar Cycle 19, the biggest in recorded history, that stretches back before the birth of radio?

From my own records, average daily sunspot numbers for April through June 2023 had a nice upward trend at 93.7, 125.8, and 143.9.

There was one new sunspot region on June 30, three more on July 1, one more on July 2, another on July 4, and one more on July 5.

Sunspot and solar flux data this week did not track with each other again. The average daily sunspot number declined from 170 to 126.1, while the average daily solar flux rose slightly from 160.3 to 164.5.

Geomagnetic indicators were lower, with the average daily planetary A index declining from 10.7 to 7.3 and middle latitude averages declining from 9.9 to 8.

Predicted solar flux is 155 and 150 on July 6 – 7; 145 on July 8 – 11; 150 and 155 on July 12 – 13; 175 on July 14 – 18; 170 on July 19 – 21; 160 on July 22 – 23; 155 on July 24 – 25; 160 on July 26 – 27; 165 on July 28 – 29; 170, 170, and 165 on July 30 through August 1, and 155 on August 2 – 6.

Predicted planetary A index is 5 on July 6 – 7; 12 and 8 on July 8 – 9; 5 on July 10 – 11; 20 and 30 on July 12 – 13; 8 on July 14 – 22; 5 on July 23 – 30; 8 on July 31 through August 1, and 5 on August 2 – 4.

Check out Tamitha Skov’s, WX6SWW, YouTube video from July 1 at https://youtu.be/HR8mm30oxOQ.

Read about a radio blackout at http://bit.ly/46tTRT8. Sunspot numbers for June 29 through July 5, 2023, were 112, 187, 119, 126, 117, 121, and 101, with a mean of 126.1. The 10.7-centimeter flux was 162.2, 158.6, 165.5, 170.2, 173.2, 167.2, and 154.6, with a mean of 164.5. Estimated planetary A indices were 17, 8, 5, 5, 5, 4, and 7, with a mean of 7.3. Middle latitude A index was 13, 8, 6, 8, 7, 5, and 9, with a mean of 8.

A comprehensive 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.

A weekly, full report is posted on ARRL News.