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.

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.

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.

Solar activity was up this week, with the average daily sunspot number increasing from 133.7 to 139, and the average daily solar flux increasing from 155.3 to 166.8.

Average daily planetary A index stayed the same at 7.3, and average middle latitude A index went from 7.9 to 8.6.

Predicted solar flux doesn’t show any improvement, with peaks at 170 on June 8 and again on June 23 – 25.

The forecast shows 170 on June 8; 165 on June 9 – 11; 160, 155, and 155 on June 12 – 14, then 145 and 150 on June 15 – 16; 155 on June 17 – 20, then 160 and 165 on June 21 – 22; 170 on June 23 – 25, then 168, 165, and 162 on June 26 – 28; 160 on June 29 through July 4, then 155, 150, and 145 on July 5 – 7.

Predicted planetary A index is 12, 8, 5, 10, and 8 on June 8 – 12; 5 on June 13 – 17, then 22, 15, 12, and 10 on June 18 – 21; 5 on June 22 – 26, then 10, 12, 5, and 5 on June 27 – 30, then 8, 12, and 8 on July 1 – 3, and 5 on July 4 – 7.

In some previous bulletins, I observed 10-meter propagation with FT8 into Florida from my QTH in Seattle, and into Mexico at a similar distance.

Recently on 10 meters, propagation has been into VK/ZL and North America, and mostly into southern California, Nevada, Utah, and Arizona. There is some seasonal variation.

Sunspot numbers for June 1 through 7, 2023, were 143, 147, 112, 110, 151, 133, and 177, with a mean of 139. 10.7-centimeter flux was 163.9, 162.3, 164.6, 168.3, 169.2, 171.8, and 167.2, with a mean of 166.8. Estimated planetary A indices were 13, 5, 5, 11, 5, 7, and 5, with a mean of 7.3. Middle latitude A index was 14, 8, 5, 11, 6, 10, and 6, with a mean of 8.6.