Solar Report for May 12, 2022

Tad Cook, K7RA, Seattle, Washington, reports:

There was some evidence of sporadic-E propagation this week on 6 and 10 meters, which is always surprising and exciting.

Solar activity was the same as last week, at least going by the numbers.

Average daily sunspot numbers rose slightly from 68.6 to 74.4, while average daily solar flux only budged from 120 to 120.3.

Geomagnetic indicators were quieter, with average daily planetary A index shifting from 10.7 to 5, and average middle latitude numbers from 9.3 to 4.6. We listed the middle latitude A index on May 6 as 2, but that number is an estimate. At the end of that day, the last K index reading was not reported, and since the A index for the day is calculated from all the K index readings, there was not any official middle latitude A index reported and was estimated on available data.

Thursday’s outlook for solar flux is more optimistic than last week’s prediction, with no values below 100. Expected flux values are 124 on May 12 – 13; 126 on May 14 – 16; 124 on May 17 – 18; 118 on May 19 – 21; 120, 124, and 121 on May 22 – 24; 118 on May 25 – 27; 116 on May 28 – 31; 118 on June 1 – 5; 116 and 118 on June 6 -7; 120 on June 8 – 9; 122 on June 10 – 14, and 118 on June 15 – 17.

Planetary A index is predicted at 6, 8, 12, 8, 14, and 8 on May 12 – 17; 5 on May 18 -19; 12 and 8 on May 20 – 21; 5 on May 22 – 23; 18 on May 24; 15 on May 25 – 27; 8 on May 28, and 5 on May 29 through June 15. There will be a nice long quiet spell of more than 2 weeks.

Wednesday’s forecast was prepared by the US Air Force personnel.

Sunspot numbers for May 5 through 11 were 85, 64, 66, 89, 71, 62, and 84, with a mean of 74.4. The 10.7-centimeter flux was 119.9, 119.2, 118.1, 119.2, 117, 115.8, and 132.9, with a mean of 120.3. Estimated planetary A indices were 4, 5, 3, 6, 8, 3, and 6, with a mean of 5. Middle latitude A index was 4, 2, 4, 7, 8, 2, and 5, with a mean of 4.6.

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.

A weekly, full report is posted on ARRL News.

May 5, 2022 Solar Report

Tad Cook, K7RA, Seattle, Washington, reports:

Spaceweather.com reported on May 4 an M5 solar flare from sunspot

group AR3004, causing a brief shortwave radio blackout over the Middle East and Africa.

Solar activity was lower this week, even though sunspots were visible every day.

Average daily sunspot numbers dropped from 109.3 to 68.6, while average daily solar flux went from 156 to 120.

Average daily geomagnetic indices were only slightly higher, with average planetary A index changing from 9.1 to 10.7, and middle latitude A index from 8 to 9.3.

Predicted solar flux looks low for the next month, even dipping below 100 in early June.

Predicted values are 135 and 138 on May 5 – 6, 145 on May 7 – 9, then 140, 130, 120, 115 and 120 on May 10 – 14, 125 on May 15 – 18, 127 on May 19 – 20, then 130, 128, 125, and 122 on May 21 – 24, 118 on May 25 – 26, then 114 and 110 on May 27 – 28, 105 on May 29 -31, then 102 and 100 on June 1 – 2, 97 on June 3 -5, then 99, 102 and 108 on June 6 – 8.

Predicted planetary A index is 5 on May 5 – 12, then 8, 10 and 8 on May 13 – 15, 5 on May 16 – 19, then 12 and 8 on May 20 – 21, 5 on May 22 – 23, 18 on May 24, 15 on May 25 – 27, then 8, 15 and 8 on May 28 – 30, and 5 on May 31 through June 8.

These predictions are from forecasters Housseal and Dethlefsen of the USAF 557th Weather Wing.

Sunspot numbers for April 28 through May 4, 2022, were 118, 90, 50, 36, 69, 53, and 64, with a mean of 68.6. 10.7 cm flux was 132.2, 123.5, 119.7, 109, 111.9, 113.8, and 130.1, with a mean of 120. Estimated planetary A indices were 14, 15, 18, 9, 6, 7, and 6, with a mean of 10.7. Middle latitude A index was 11, 10, 16, 9, 6, 7, and 6, with a mean of 9.3.

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

4/30/22 Solar Report

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.

Solar Report April 21, 2022

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

4-14-22 Solar Report

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.