Sunspot numbers were lower again this week, with the average declining from 143.6 two weeks ago to 118.7 last week, and now 68 this week. Average daily solar flux sank eight points, from 153.6 last week to 145.6 this week.
Six new sunspot groups emerged over the week: one on March 17, another March 18, three more on March 19, one more on March 21, and another on March 22.
Predicted solar flux is 155, 150, and 145 on March 23 – 25; 140 on March 26 – 27, then 130, 130, and 140 on March 28 – 30; 138 on March 31 through April 1, then 136, 136, and 134 on April 2 – 4; 132 on April 5 – 7; 130 on April 8 – 9, then 132, 135, 138, and 140 on April 10 – 13; 142 on April 14 – 15; 143 on April 16; 140 on April 17 – 18; 142 on April 19 – 21, and 144 on April 22.
Predicted planetary A index is very active over the next few days, at 20, 40, 30, 20, and 15 on March 23 – 27; 8 on March 28 – 29; 20 and 18 on March 30 – 31; 12 on April 1 – 2; 10 and 8 on April 3 – 4; 5 on April 5 – 9, then 15, 12, 8, and 5 on April 10 – 13: 8 on April 14 – 15, then 12, 10, 5, and 5 on April 16 – 19, then 10, 36, 20, 10, and 8 April 20 – 24.
Sunspot numbers for March 16 through 22, 2023, were 84, 58, 35, 73, 75, 70, and 81, with a mean of 68. 10.7-centimeter flux was 135.4, 134.2, 140.3, 142.7, 156.1, 151.6, and 158.9, with a mean of 145.6. Estimated planetary A indices were 8, 7, 8, 10, 13, 8, and 17, with a mean of 10.6. Middle latitude A index was 6, 7, 6, 8, 10, 8, and 14, with a mean of 8.4.
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.
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