Tad
Cook, K7RA, Seattle, Washington, reports:
On April 28, 2022, the Australian Space Forecast Centre issued a
geomagnetic disturbance warning, stating, “The Earth is currently under the influence of moderately elevated solar wind speed associated with a southern coronal hole. Late on April 29, solar wind conditions are expected to enhance further due to the possible arrival of the 27 April CMEs [Coronal Mass Ejections]. G0-G1 conditions are likely for next three days with a chance of G2 on April 29 due to both coronal hole effects and impending impact of the CMEs. Aurora may be visible from Tasmania, southern coastline Victoria and southwest Western Australia.”
On Wednesday sunspot groups threaded across the sun from southeast to northwest. Daily sunspot number peaked at 126 on Tuesday, and average daily sunspot number for the week was 109.3, up from 64.4 last week. Daily solar flux peaked at 164.4 on Thursday, April 21, and the average for the week was 156, which was up from 133.9 in the previous week.
Predicted solar flux is 140 and 125 on April 28 – 29; 110 on April 30 – May 1; 105 on May 2 – 5; 130 on May 6 – 7; 128 on May 8; 130 on May 9 – 10; 135 on May 11 – 12; 140 on May 13 – 15; 160 on May 16 – 21; 135 on May 22; 132 on May 23 – 25; 125 on May 26 – 27; 130 on May 28 – 31, and 125 on June 1.
Predicted planetary A index is 8, 18, 10 and 8 on April 28 through May 1; 5 on May 2 – 5; 8, 15, 12, and 8 on May 6 – 9; 5 on May 10 – 12; 8, 10, 8, and 8 on May 13 – 16; 5 on May 17 – 19; 10 and 8 on May 20 – 21; 5 on May 22 – 25; 18, 12, and 8 on May 26 – 28, and 5 on May 29 through June 1.
In Friday’s bulletin look for a report by KD9KCK of some astonishing 10-meter conditions on Wednesday.
Sunspot
numbers for April 21 – 27, were 119, 101, 118, 112, 94, 126, and 95, with a
mean of 109.3. 10.7-centimeter flux was 164.4, 162.5, 159.8, 158.5, 156.6,
148.9, and 141.5, with a mean of 156. Estimated planetary A indices were 10, 7,
13, 5, 5, 3, and 21, with a mean of 9.1. Middle latitude A index was 9, 7, 12,
5, 4, 3, and 16, with a mean of 8.
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.