Solar Report 8-11-23

Two new sunspot groups appeared on August 3, and then three more appeared on August 7, followed by another on August 9.

But solar activity was lower during our current reporting week of August 3 – 9, with the average daily sunspot number dropping from 154.3 to 108.9, and average solar flux from 173 to 166.4.

The average daily planetary A index rose from 8.3 to 12.3, and the average middle latitude A index rose from 9.3 to 10.1.

The middle latitude A index on August 3 – 4 was not available, so I estimated the value based on the planetary A index and remaining five middle latitude readings for the rest of the week.

Predicted solar flux is 150 on August 10 – 12; 145, 140, 130, and 135 on August 13 – 16; 162 on August 17 – 18; 164 on August 19 – 20; 168 on August 21 – 23; 172, 172, and 170 on August 24 – 26; 172, 172, and 174 on August 27 – 29; 172, 172, and 170 on August 30 – September 1; 168, 168, 166, and 164 on September 2 – 5, and 162, 162, 164, and 164 on September 6 – 9.

Predicted planetary A index is 12 on August 10; 5 on August 11 – 14; 12 and 8 on August 15 – 16; 5 on August 17 – 25; 12 on August 26, and 5 on August 27 – September 4.

On August 9, Spaceweather.com wrote about a 1940 geomagnetic storm that sounds similar to the infamous Carrington Event.

Two coronal mass ejections hit Earth, each 109 minutes apart. Read a recent scientific paper on the event at https://bit.ly/3s1VrMh.

Check out the following articles on solar flares:

https://bit.ly/3KXlUl1

https://bit.ly/3qj0pE6

https://bit.ly/3QPYPV9

https://bit.ly/45naVsF

Space weather forecaster Dr. Tamitha Skov, WX6SWW, recently uploaded this video:

https://youtu.be/Olfjss8GmSI Sunspot numbers for August 3 – 9, 2023, were 124, 122, 100, 97, 101, 115, and 103, with a mean of 108.9. The 10.7-centimeter flux was 162.9, 170.8, 175.8, 173.5, 169.7, 158.9, and 153.4, with a mean of 166.4. Estimated planetary A indices were 6, 13, 36, 4, 12, 8, and 7, with a mean of 12.3. Middle latitude A index was 5, 12, 24, 4, 11, 7, and 8, with a mean of 10.1.


Latest Solar Report

The Australian Space Weather Forecasting Centre issued a geomagnetic disturbance warning at 0233 UTC on August 3, 2023:

“Two recent coronal mass ejections (CMEs) are expected to impact Earth on UT day 05-Aug, with the second possibly arriving early 06-Aug. G0-G1 geomagnetic conditions may be expected on 05-Aug, with a chance for isolated periods of G2 towards the end of the UT day on 05-Aug. Geomagnetic storm conditions may persist over 06-Aug.”

Solar activity was up during this reporting week, July 27 through August 2.

Average daily sunspot numbers increased from 128.1 to 154.3, but the average daily solar flux was about the same as last week, moving from 172.2 to 173.

Geomagnetic indicators were quiet, with the average daily planetary A index shifting from 11 to 8.3, while middle latitude numbers went from 11.1 to 9.3.

Predicted solar flux is 170 and 165 on August 3 – 4; 160 on August 5 – 7; 155, 145, and 168 on August 8 – 10; 168 on August 11 – 12; 170 on August 13 – 16; 172 on August 17 – 18; 170 and 168 on August 19 – 20; 170 on August 21 – 22; 172 on August 23; 170 on August 24 – 27, and 165 on August 28 – 31.

Predicted planetary A index is 10, 20, 28, 15, and 8 on August 3 – 7; 5, 5, and 10 on August 8 – 10; 8 on August 11 – 12; 5 on August 13 – 25; 12 and 10 on August 26 – 27, and 5 on August 28 – 31.

ARRL published an excellent new book, Here to There: Radio Wave Propagation, written by a team of experts, including Frank Donovan, W3LPL; Nathaniel Frissell, W2NAF, and Carl Luetzelschwab, K9LA. It’s a great reference on all aspects of HF and VHF propagation and it includes a survey of the various propagation prediction computer programs.

Sunspot numbers for July 27 through August 2 were 154, 148, 147, 139, 197, 160, and 135, with a mean of 154.3. The 10.7-centimeter flux was 165.3, 168.2, 178.6, 174.4, 177.1, 174.7, and 172.9, with a mean of 173. Estimated planetary A indices were 7, 6, 9, 9, 6, 9, and 12, with a mean of 8.3. Middle latitude A index was 7, 5, 8, 18, 8, 9, and 10, with a mean of 9.3.

Weekly Solar Report 7/27/23

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.

This week’s ARRL Propagation Bulletin, ARLP029:

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.



7-14-23 Solar Report

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.



July 7 Solar Report

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.



2023 Annual Picnic

6-29-2023 Solar Report

Conditions were favorable over Field Day weekend, with the exception of a brief period where planetary K index was at 5 on Saturday night.

There were five new sunspot groups on June 23, two more on June 24, another on June 26, and another on June 27.

Average daily sunspot numbers were up, and solar flux was down.

The average daily sunspot number rose from 143 to 170, and the average daily solar flux declined slightly from 165.4 to 160.3.

This was unexpected because we normally see these values track together.

Predicted solar flux is 155 on June 29; 150 on June 30 through July 4; 145 on July 5; 135 on July 6 – 8; 145, 155, 160, 165, and 170 on July 9 – 13; 175 on July 14 – 18; 170 on July 19 – 21; 160, 150, 145, 145, 140, and 135 on July 22 – 27, and 130 on July 28 – 31.

Predicted planetary A index is 5 on June 29 – 30; 15 and 10 on July 1 – 2; 5 on July 3 – 7; 12 and 8 on July 8 – 9; 5 on July 10 – 11; a stormy 20 and 30 on July 12 – 13; 8 on July 14 – 23; 12 on July 24 – 25, and 8 on July 26 – 27.

Read about the cycle peak and see images at https://bit.ly/3ps6iOI.

Check out a useful glossary for space weather terms at https://bit.ly/3XuimeQ.

Sunspot numbers for June 22 – 28, 2023, were 176, 194, 200, 180, 158, 141, and 141, with a mean of 170. 10.7-centimeter flux was 173.2, 169.7, 160.8, 154.8, 157.7, 151.2, and 154.9, with a mean of 160.3. Estimated planetary A indices were 8, 9, 16, 15, 11, 8, and 8, with a mean of 10.7. Middle latitude A index was 8, 9, 16, 10, 11, 7, and 8, with a mean of 9.9.

This weeks Solar Report

Sunspot numbers and solar flux rose this week. There were two new sunspot groups on June 15, another on June 17, one more on June 18, three more on June 19, two more on June 20, and another on June 21.

The average daily sunspot number increased from 122 to 143, and the average daily solar flux rose from 154.8 to 165.4.

The average daily planetary A index jumped from 5.7 to 15.4, while the middle latitude numbers increased from 6.7 to 13.1.

Predicted solar flux is 175, 180, and 180 on June 22 – 24; 185 on June 25 – 27; 180 on June 28; 175 on June 29 through July 1; 180 on July 2 – 3; 175 on July 4 – 5; 170 on July 6 – 10; 165, 160, and 160 on July 11 – 13; 165, 160, and 160 on July 14 – 16; 155, 160, and 160 on July 17 – 19, and 165 on July 20 – 24.

Predicted planetary A index is 12, 15, 10, and 8 on June 22 – 25; 5, 5, and 12 on June 26 – 28; 5, 5, and 12 again on June 29 through July 1; 8 on July 2; 5 on July 3 – 7; 12 on July 8; 5 on July 9 – 11; 20 and 30 on July 12 – 13; 8 on July 14 – 15, and 12 on July 16 – 17.

These predictions are from forecasters Reilly and Kiser of the US Air Force 557th Weather Wing at Offutt Air Force Base, Nebraska. See https://bit.ly/3qRNJnr for more details.

So, what does this forecast show for ARRL Field Day this weekend?

Geomagnetic numbers are a bit more unsettled than what was shown in last week’s bulletin, which had an A index of 5 for Friday through Sunday. The latest shows 15, 10, and 8. Predicted solar flux looks excellent at 180, 180, and 185.

Of course, Field Day does not begin until Saturday morning, but here is data for the day prior.

Watch a video on the X1.1 solar flare at https://bit.ly/3CI0OCA.

There was another report from South Asia regarding solar flares as some sort of existential threat.

Don’t worry, there was nothing terrifying about what they reported, but there is a nice description of what the NASA-ESA Solar and Heliospheric Observatory (SOHO) does to monitor it at https://bit.ly/444VhSk. Visit SOHO’s website at https://soho.nascom.nasa.gov.

Look for an updated forecast for ARRL Field Day in Friday’s bulletin.

Sunspot numbers for June 15 – 21 were 112, 120, 110, 133, 181, 155, and 190, with a mean of 143. The 10.7-centimeter flux was 153.1, 157.2, 158.1, 164.1, 168.8, 180.1, and 176.4, with a mean of 165.4. Estimated planetary A indices were 24, 38, 8, 10, 10, 10, and 8, with a mean of 15.4. Middle latitude A index was 17, 24, 8, 12, 9, 13, and 9, with a mean of 13.1.

6-16-23 Solar report

Solar activity declined this week, with average daily sunspot numbers dropping from 139 to 122, and the average daily solar flux decreasing from 166.8 to 154.8. This contrasts the current reporting week of June 8 – 14with the previous 7 days.

The average daily planetary A index decreased from 7.3 to 5.7, and average daily middle latitude A index from 8.6 to 6.7.

On June 14, spaceweather.com reported two new sunspot groups emerging across the sun’s southeastern horizon.

Forecasters Gervase and Kiser of the U.S. Air Force predict that the solar flux will be 150 on June 15 – 16; 155 on June 17 – 18; 150, 155, 155, and 165 on June 19 – 22; 170 on June 23 – 25; 168, 165, and 162 on June 26 – 28; 160 on June 29 through July 4; 165 on July 5; 170 on July 6 – 8; 155, 157, 153, and 160 on July 9 – 12; 150 on July 13 – 14, and 155 on July 15 – 17.

Predicted planetary A index is 8, 14, 10, and 8 on June 15 – 18; 5, 5, and 8 on June 19 – 21; 5 on June 22 – 26; 12 on June 27 – 28; 5 on June 29 – 30; 12 and 8 on July 1 – 2; 5 on July 3 – 7; 12 on July 8 – 10; 5, 5, and 12 on July 11 – 13, and 10 on July 14 – 15.

These predictions look great for ARRL Field Day (June 24 – 25) because solar flux peaks at 170 on June 23 – 25, and the predicted planetary A index is a nice, quiet 5 on June 22 – 26. Next week, we will present an updated forecast just prior to Field Day weekend.

Follow the link below for an image of the ISS over a sunspot:

https://bit.ly/3NgsByW

This link shows the same, but in video format:

https://bit.ly/43Em3B1

Check out this link for a study of the sun’s coldest region:

https://bit.ly/3X6ErQu

More sunspots can be seen at the following link:

https://bit.ly/3Nt5Ys6

Sunspot numbers for June 8 – 14, 2023, were 149, 152, 116, 116, 116, 98, and 107, with a mean of 122. The 10.7-centimeter flux was 168.5, 164.3, 161.2, 153.8, 146.1, 146.3, and 143.5, with a mean of 154.8. Estimated planetary A indices were 5, 4, 5, 9, 6, 6, and 5, with a mean of 5.7. Middle latitude A index was 6, 6, 4, 10, 8, 8, and 5, with a mean of 6.7.