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.

Tad Cook, K7RA, Seattle, Washington, reports:

This Solar Dynamics Observatory Image was taken on April 21, 2022. [Photo courtesy of NASA SDO/HMI]

Solar flares emerged daily over the last reporting week. On April 20, 2022, Spaceweather.com reported “Solar Activity is Intensifying,” and over the past 24 hours, there were 19 solar flares, including six M-class events, and a powerful X2.2-class solar flare.

Daily sunspot numbers averaged 64.4, 30 points higher than last week, and average daily solar flux also rose 30 points from 103.1 to 133.1.

Even with all flares and coronal mass ejections (CMEs), geomagnetic indicators were lower, with average planetary A index going from 16.9 to 14.6, and middle latitude numbers dropping from 12.6 to 10.9.

Predicted solar flux looks moderate, at 130 on April 21 – 27; 132 on April 28; 125 on April 29 – 30; 130 on May 1 – 4; 125 on May 5; 130 on May 6 – 7; 128 on May 8; 130 on May 9 – 10; 135 on May 11 – 12; 140 on May 13 – 14; 135 on May 15; 130 on May 16 -18; 135 on May 19; 130 on May 20 – 21; 135 on May 22, and 132 on May 23 – 25.

Predicted planetary A index is 5 on April 21 – 22; 12 on April 23; 8 on April 24 – 26; 5 on April 27 – 28; 18, 12, and 8 on April 29 – May 1; 5 on May 2 – 5; 8, 15, 12, and 8 on May 6 – 9; 5 on May 10 – 12; 8, 10, and 12 on May 13 – 15; 10 on May 15 – 17; 8 on May 18 – 19; 12 and 8 on May 20 – 21, and 5 on May 22 – 25. Sunspot numbers for April 14 – 20 were 37, 35, 78, 74, 79, 68, and 80, with a mean of 64.4. The 10.7-centimeter flux was 103.4, 110.3, 122.4, 134.9, 140.5, 160.1, and 160, with a mean of 133.1. Estimated planetary A indices were 38, 21, 8, 11, 8, 7, and 9, with a mean of 14.6. Middle latitude A index was 22, 14, 7, 9, 7, 8, and 9, with a mean of 10.9

Tad Cook, K7RA, Seattle, Washington, reports:

At 0010 UTC on April 14, the Australian Space Forecast Centre issued

This Solar Dynamics Observatory Image was taken on April 14, 2022. [Photo courtesy of NASA SDO/HMI]

a Geomagnetic Disturbance Warning that stated, “Increased geomagnetic activity expected due to coronal mass ejection from April 14 – 15 2022.”

Sunspot numbers and solar flux declined this reporting week (April 7 -13), although solar activity was not really down, Instead, there were solar flares and coronal mass ejections (CMEs) every day, causing disruptions to HF radio communication.

There was a new sunspot appearance on April 7, and another on each day from April 11 – 13. Yet, average daily sunspot numbers declined from 94.6 to 34.4, and average daily solar flux dropped from 135.3 to 103.1.

Average daily planetary A index increased from 14.4 to 15.9. Average middle latitude A index, measured at a single magnetometer in Virginia, went from 10.9 last week to 12.6 this week.

The latest solar flux prediction from the US Air Force Space Weather Squadron, via he National Oceanic and Atmospheric Administration (NOAA), shows modest activity for the next month at 100, 103, 105, and 106 on April 14 – 17; 105 on April 18 – 19; 108 and 106 on April 20 – 21; 110 on April 22 – 23; 115 on April 24; 118 on April 25 – 28; 116 on April 29 through May 6; 112 and 98 on May 7- 8; 95 on May 9 – 11; 98 and 102 on May 12 – 13, and 106 on May 14 – 18.

Predicted planetary A index is 35, 20, 12, 8, and 5 on April 14 – 18; 10, 8, 10, 5, 15, 10, and 8 on April 19 – 25; 5 on April 26 – 28; 18, 12, and 8 on April 29 through May 1; 5 on May 2 – 5; 8, 15, and 12 on May 6 – 8; 5 on May 9 – 11; 12 and 8 on May 12 – 13; 5 on May 14 – 16, and 10 on May 17 – 18.

Sunspot numbers for April 7 – 13 were 52, 55, 37, 13, 24, 23, and 37, with a mean of 34.4. The 10.7-centimeter flux was 111.1, 108.9, 107.1, 101.1, 98.7, 96.2, and 98.7, with a mean of 103.1. Estimated planetary A indices were 15, 9, 19, 34, 13, 12, and 9, with a mean of 15.9. Middle latitude A index was 12, 9, 17, 18, 13, 10, and 9, with a mean of 12.6.

Tad Cook, K7RA, Seattle, Washington, reports:

New sunspot groups appeared on March 31, April 1, April 2, April 3, and April 5. This Solar Dynamics Observatory (SDO) image was taken on April 7, 2022. [NASA SDO/HMI photo]

A lot of solar activity livened up HF conditions over the past reporting week, March 31 to April 6. Average daily sunspot number rose from 90.1 to 94.6, and daily solar flux from 132.7 to 135.3.

A new sunspot group appeared on March 31, two more on April 1, another on April 2, one more on April 3, and another on April 5.

Predicted solar flux is 116, 115, 118, 112, and 110 on April 7 – 11, 108 on April 12 – 14, 120 on April 15 – 17, 125 on April 18 – 19, 130 on April 20 – 23, 140 on April 24 – 28, 135 on April 29 – 30, 130 on May 1, 120 on May 2 – 3, 125 on May 4 – 5, 120 on May 6, 115 on May 7 – 8, and 110 on May 8 – 9.

Predicted planetary A index is 25, 12, 15, 10, and 8 on April 7 – 11; 5 on April 12 – 19; 10 on April 29 – 21; 5, 15, 10, and 8 on April 22 – 25; 5 on April 26 – 28; 18, 12, 10, and 8 on April 29 through May 2; 5 on May 3 – 7, and 12 and 10 on May 8 – 9.

Sunspot numbers for March 31 through April 6, 2022 were 84, 109, 118, 129, 86, 75, and 61, with a mean of 94.6. The 10.7-centimeter flux was 149, 3, 146.6, 143.3, 140.2, 128, 122.4, and 117, with a mean of 135.3. Estimated planetary A indices were 27, 17, 22, 10, 11, 6, and 8, with a mean of 14.4. Middle latitude A index was 18, 12, 19, 7, 8, 6, and 6, with a mean of 10.9.

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.

On May 1.2022 the Sunday night informational net will come to an end for the late Spring, Summer and early Fall months. Continue to watch this site for any updates to the repeater system. Hope you all have a great and enjoyable summer months and will see you again next Fall.