Propagation Bulletin, ARLP023

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.