The Australian Space Weather Forecasting Centre issued a geomagnetic disturbance warning at 0233 UTC on August 3, 2023:
“Two recent coronal mass ejections (CMEs) are expected to impact Earth on UT day 05-Aug, with the second possibly arriving early 06-Aug. G0-G1 geomagnetic conditions may be expected on 05-Aug, with a chance for isolated periods of G2 towards the end of the UT day on 05-Aug. Geomagnetic storm conditions may persist over 06-Aug.”
Solar activity was up during this reporting week, July 27 through August 2.
Average daily sunspot numbers increased from 128.1 to 154.3, but the average daily solar flux was about the same as last week, moving from 172.2 to 173.
Geomagnetic indicators were quiet, with the average daily planetary A index shifting from 11 to 8.3, while middle latitude numbers went from 11.1 to 9.3.
Predicted solar flux is 170 and 165 on August 3 – 4; 160 on August 5 – 7; 155, 145, and 168 on August 8 – 10; 168 on August 11 – 12; 170 on August 13 – 16; 172 on August 17 – 18; 170 and 168 on August 19 – 20; 170 on August 21 – 22; 172 on August 23; 170 on August 24 – 27, and 165 on August 28 – 31.
Predicted planetary A index is 10, 20, 28, 15, and 8 on August 3 – 7; 5, 5, and 10 on August 8 – 10; 8 on August 11 – 12; 5 on August 13 – 25; 12 and 10 on August 26 – 27, and 5 on August 28 – 31.
ARRL published an excellent new book, Here to There: Radio Wave Propagation, written by a team of experts, including Frank Donovan, W3LPL; Nathaniel Frissell, W2NAF, and Carl Luetzelschwab, K9LA. It’s a great reference on all aspects of HF and VHF propagation and it includes a survey of the various propagation prediction computer programs.
Sunspot numbers for July 27 through August 2 were 154, 148, 147, 139, 197, 160, and 135, with a mean of 154.3. The 10.7-centimeter flux was 165.3, 168.2, 178.6, 174.4, 177.1, 174.7, and 172.9, with a mean of 173. Estimated planetary A indices were 7, 6, 9, 9, 6, 9, and 12, with a mean of 8.3. Middle latitude A index was 7, 5, 8, 18, 8, 9, and 10, with a mean of 9.3.