The recent decline in solar activity continues. The weekly average daily sunspot numbers, starting with ARLP039 on September 21, were 170.6, 128.6, 144.1, and 89.4. This week’s average daily sunspot number was 41.9. The weekly average daily solar flux for the same period was 168.8, 155.6, 159.1, 145.1, and 123.5.
On October 25, Spaceweather.com noted, “Solar Cycle 25 roared to life in 2021 – [2023], dashing predictions of a weak solar cycle. Forecasters have since been expecting a robust Solar Max in 2024 or 2025. Suddenly, however, sunspot counts are dropping.” They also noted that temporary lulls are common in strong sunspot cycles, and strong activity should resume soon, with a cycle peak occurring within the next 2 years. They provided a recent link to the NOAA Space Weather Scale at https://bit.ly/3FyVWko.
Three new sunspot groups appeared this week on October 20 – 22.
Predicted solar flux is 125 on October 26 – 28; 120 on October 29 through November 1; 150 on November 2 – 5; 140 on November 6 – 9; 135 on November 10 – 11; 145, 140, 135, and 135 on November 12 – 15; 140 on November 16 – 18; 135 and 140 on November 19 – 20, and 145 on November 21 – 24.
Predicted planetary A index is 5, 8, 5, 5, 18, and 10 on October 26 – 31; 5 on November 1 – 8; 12 and 8 on November 9 – 10; 5 on November 11 – 12; 12 on November 13 – 14; 10 and 8 on November 15 – 16; 5 on November 17 – 22, and 8 on November 23 – 26.
Jon Jones, N0JK, QST columnist for “The World Above 50 MHz QST” wrote:
“The weekend of October 20 – 22 had some outstanding propagation on 6 meters.
On the afternoon of Saturday, October 21, there was E-layer or sporadic-E propagation linking to trans-equatorial paths to the [South] Pacific from the Midwest. N0LL copied FK8CP and ZL1RS on just a ham stick vertical antenna while driving from Salina to his home in Smith Center, KS. He later worked E51WL from his home around 2130Z.
I was staying at the La Quinta Inn in Scottsdale for the weekend [and] had my MFJ-9406 [with me]. Using a dipole antenna in the hotel room, I copied N0LL EM09, N0KQY DM998, and N0OT DM88 on 6-meter Es, calling DX stations around 1945Z. Es in October are rare, and Es links rarer still.
[On October 22], I managed to work W5JAY EM26 on [6-meter] FT8 via Es at 0136 [UTC.] Power was 7 watts to the indoor dipole. East coast stations were working the South Pacific on Es links to TEP.
That next afternoon, Arizona had Es link[s] to TEP to South America. I copied XE1H DL80 at the first Es hop. 231022_233300 50.313 Rx FT8 -8 0.2 1612 CQ XE1H DL80.
October 24 at 2335 UTC copied PY5CC GG54 via Es link to TEP.
Spaceweather.com noted a coronal mass ejection (CME) impact [on] October 20. The active geomagnetic field boosted the TEP MUF and may have sparked some of the sporadic -E as well.
Note that this weekend is the SSB portion of the CQ World Wide DX Contest.
See https://www.cqww.com/ for more information.
Sunspot numbers for October 19 – 25, 2023, were 39, 56, 65, 48, 25, 34, and 26, with a mean of 41.9. The 10.7-centimeter flux was 128.7, 125.7, 122.6, 118.8, 122.1, 121.1, and 125.8, with a mean of 123.5. Estimated planetary A indices were 10, 8, 22, 8, 3, 4, and 4, with a mean of 8.4. The middle latitude A index was 8, 8, 13, 7, 2, 2, and 3, with a mean of 6.1.
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.
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