Tad Cook, K7RA, Seattle, reports: Solar activity was weak over the February 24 – March 2 reporting week with average daily sunspot numbers weakening from 54.3 to 44, but average daily solar flux rising slightly from 95.4 to 98.3.

Geomagnetic numbers were moderate. Average daily planetary A index declined from 9.6 to 7.3, and the middle latitude index from 7.3 to 5.6.

Predicted solar flux is 115 on March 3 – 4; 110 on March 5 – 6; 105 on March 7; 100 on March 8 – 10; 99 on March 11 – 13; 98 on March 14; 95 on March 15 – 16; 96, 97, 98, and 99 on March 17 – 20; 100 on March 21 – 22; 101 and 100 on March 23 – 24; 102 on March 25 – 26; 99 and 102 on March 27 – 28; 105 on March 29 – 31; 102 on April 1 – 2; 101 on April 3 – 4, and 100 on April 5 – 6.

Predicted planetary A index is 5, 8, 12, and 8 on March 3 – 6; 5 on March 7 – 10; 15, 12, 8, 5, and 8 on March 11 – 15; 5 on March 16 – 17; 10 on March 18; 15 on March 19 – 21; 7 on March 22 – 24; 5 and 10 on March 25 – 26; 12 on March 27 – 28; 8 on March 29 – 30; 12 on March 31; 15 on April 1 – 2, and 5 on April 3 – 6.

Sunspot numbers for February 24 – March 2 were 23, 22, 22, 48, 65, 62, and 66, with a mean of 44. The 10.7-centimeter flux was 92.3, 96.2, 96.5, 96.9, 99, 99.3, and 109.5, with a mean of 98.5. Estimated planetary A indices were 7, 8, 3, 13, 8, 8, and 4, with a mean of 7.3. Middle latitude A index was 6, 7, 1, 11, 5, 6, and 3, with a mean of 5.6.

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.

• SEA-PAC 2022 online registration has been delayed due to technical difficulties restarting the registration web pages. SEA-PAC anticipates that online Registration will open on March 7 at 6 PM Pacific Time. SEA-PAC 2022 will host the ARRL Northwestern Division Convention June 3 – 5. The 2022 SEA-PAC QSO Party is being planned for the weekend before the event.

Tad Cook, K7RA, Seattle, reports: New sunspot groups appeared on February 17, 19, 20, and 21, but solar activity declined, even though sunspots were covering the sun every day.

The average daily sunspot number declined by 21 points, from 75.3 last week to 54.3 in the February 17-23 reporting week. Average daily solar flux was down by nearly 15 points, from 110.1 to 95.4.

The average daily planetary A index went from 13 to 9.6, and the average daily middle latitude A index was off by a point to 7.3.

Predicted solar flux is 100 on February 24; 105 on February 25 – March 2; 110 on March 3 – 4; 108 on March 5 – 8; 105 on March 9 – 11; 103 on March 12 – 13; 100 on March 14; 98 on March 15 – 16; 102 on March 17 – 19; 104 on March 20 – 22; 108 on March 23 – 26; 110 on March 27; 115 on March 28 – 29, then 112 and 110 on March 30 – 31.

Predicted planetary A index is 5 on February 24 – 25; 10 on February 26; 8 on February 27 – March 2; 12, 15, 10, and 8 on March 3 – 6; 5 on March 7 – 10; 15, 12, and 10 on March 11 – 13; 5 on March 14 – 18; then 8, 5, 12, 18, 15, and 10 on March 19 – 24; 5 on March 25 – 29, and 12, 15, 10, and 8 on March 30 – April 2.

Sunspot numbers for February 17 – 23 were 103, 53, 51, 49, 48, 38, and 38, with a mean of 54.3. The 10.7 – centimeter flux was 96.7, 93.3, 95.7, 93.3, 97.8, 95.3, and 95.5, with a mean of 95.4. Estimated planetary A indices were 5, 6, 9, 13, 12, 16, and 6, with a mean of 9.6. Middle latitude A index was 4, 5, 6, 8, 11, 13, and 4, with a mean of 7.3.

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, Seattle, reports: Although solar activity was generally lower this week, new sunspots appeared. A sunspot group emerged on February 10, two more on February 11, two more on February 14 and three more on February 16, when the daily sunspot number rose to 111, the highest value for this reporting week and well above the weekly average, which was 75.3. The average for the previous week was 83.9.

The February 16 count of 111 was the highest since the end of 2021, when sunspot numbers went as high as 147 following a few days with no sunspots at all.

Average daily solar flux declined from 126 to 110.1. Average daily planetary A index went from 14.4 to 13, and average daily middle latitude A index declined just 1.3 points to 8.3.

Why do we care about sunspot numbers? Because high values correlate with greater density in the ionosphere, which gives us better propagation at higher frequencies. Sixty-four years ago, sunspot numbers were so high that hams saw worldwide around-the-clock propagation on 10 meters. Sunspot numbers have never been so high before or since.

Predicted solar flux over the next month is 105 on February 17 – 18; 108 on February 19 – 27; 110 on February 28; 115 on March 1 – 2; 112 and 110 on March 3 – 4; 108 on March 5 – 8; 105 on March 9 – 11; 103 on March 12 – 13; 100 on March 14; 98 on March 15 – 16; 102 on March 17 – 19; 104 on March 20 – 22, and 108 on March 23 – 26.

Predicted planetary A index is 5 on February 17 – 18; 15, 18, and 15 on February 19 – 21; 8 on February 22 – 23; 15 and 10 on February 24 – 25; 5 on February 26 – March 2; 12, 15, 10, and 8 on March 3 – 6; 5 on March 7 – 10; then 15, 12, and 10 on March 11 – 13; 5 on March 14 – 18, and 8, 5, 12, 15, and 10 on March 19 – 23.

Sunspot numbers for February 10 – 16 were 78, 86, 54, 53, 72, 73, and 111, with a mean of 75.3. The 10.7-centimeter flux was 118, 113.1, 110.5, 105.4, 106.5, 114.3, and 102.9, with a mean of 110.1. Estimated planetary A indices were 21, 20, 13, 15, 8, 5, and 9, with a mean of 13. Middle latitude A index was 12, 12, 10, 9, 6, 3, and 6, with a mean of 8.3.

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.