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.
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