Eleven new sunspot groups emerged over the past week, August 10-16, but average solar indicators declined.

There were two new sunspots groups on August 11, three more on August 13, another on August 14, two more on August 15, and three more on August 16. On August 17 another new one appeared.

But average daily sunspot numbers declined from 108.9 to 95.7, while average daily solar flux dropped from 166.4 to 154.2.

Predicted solar flux is 150, 155, and 157 on August 18-20, 160 on August 21-22, then 162, 165, 162, 160 and 164 on August 23-27, 168 on August 28-31, then 165, 163 and 160 on September 1-3, then 158, 155, 152 and 150 on September 4-7, and 148, 142, 140 and 130 on September 8-11, 135 on September 12-14, and 145, 150, 155, 158 and 160 on September 15-19, 162 on September 20-21, then 160 and 164 on September 22-23, and 168 on September 24-27.

Predicted planetary A index is 12 and 8 on August 18-19, 5 on August 20-25, 12 on August 26, 5 on August 27 through September 5, then 10, 8 and 8 on September 6-8, 5 on September 9-11, then 12, 15, 12 and 8 on September 12-15, 5 on September 16-21, 12 on September 22, and 5 on September 23 through the end of the month.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere August 18-24, 2023 from OK1HH:

"Solar activity has declined, both spot and flare. We have usually observed C-class solar flares, although the configurations of some active regions did not preclude the formation of M-class flares. We expect an upsurge in solar activity in the last five days of August, after which more sunspot groups should appear at the eastern limb of the solar disk.

The Earth's ionosphere was quite sensitive to the increased influx of protons in the accelerated solar wind on 11 August and again on 16-17 August. Propagation improved on August 14-15 and worsened on August 16. I do not expect any other surprises before the end of the month."

Bil Paul, KD6JUI, who often reports HF operations from his kayak, wrote:

"I recently returned from a vacation at Lake Tahoe where I was running 10 watts into an end-fed half-wave wire vertical. The rental place was surrounded by extra-tall pine trees, but the base of the antenna was 30 feet above the ground on a high porch.

My discovery (on the evenings of August 7 and 9, around 8 p.m. Pacific Coast time) was that CW DX was coming in on the 30-meter band. On the 7th, I contacted OV1CDX in Denmark on that band (and heard him again on subsequent nights). On the 9th, I contacted 6B2A in Egypt, who was coming in a solid S4.

I had a couple other CW DX twilight/early-night contacts on 15 and 20 meters, but the 30 meter contacts surprised me."

N4KZ reports from Frankfort, Kentucky:

"Last week, I began copying SSB signals from Europe on the 10 and 12-meter bands.  They were weak but readable. It was the first time I've heard SSB signals on those bands from that part of the world in many months. Then, on August 15th beginning at 1248 UTC, I worked stations across Europe and the Middle East on 12-meter SSB with strong signals.

About 20 minutes earlier, I tuned across the 10-meter phone band and only copied one signal. It was S79VU, Ravi, in the Seychelles. He was about S5 and working Europeans who I did not copy. But he came back to me on my first call. We've worked before but this was our first 10-meter QSO. It's only mid-August, but perhaps autumn propagation is beginning to emerge and with the continuing high sunspot count, I hope this marks the start of better HF conditions this fall and winter. I run about 800 watts into a multi-band Yagi with 3 active elements on each band. The antenna is up 55 feet. I live on a hilltop with a steep slope toward the north which has proven over the years to be an advantage.

On July 1, I once again became active on the low-end of 2 meters doing weak-signal work. I was quite active on SSB and CW on the low end throughout the 1980s and '90s and to a lesser extent until about 2010. I worked 40 states from Kentucky but eventually decided to concentrate on HF and 6 meters. But I missed 2 meters and now I have returned.

There's less SSB and CW than there used to be but quite a few are operating FT8 on 144.174 MHz which does a nice job with weak signals. So far I have worked 15 states and Ontario. Morning propagation a couple hours after sunrise allows for 300-400 mile QSOs routinely on FT8. And I've copied stations from Colorado, Long Island, NY and Connecticut on meteor scatter while using MSK144. After a 12-year hiatus from 2-meter weak-signal work, it's good to be back."

AA6XE in Fremont, California wrote:

"Interesting conditions on 10 meters although not that unusual. In the last couple of days propagation into the Pacific Northwest has materialized. A bunch of Beacons have surfaced. Beacons from

Portland to well north of Vancouver BC are coming in every afternoon. I heard Tad Cook's (K7RA) 10 meter beacon yesterday (Aug 13). Beacons out of Mexico have been coming in on 10 Meters for over a month. Some of those beacons are located as far South as Veracruz. Beacons from Australia have been coming through on most days over the last month. NCDXF beacons VK6RBP in Western Australia and 4S7B in Sri Lanka were heard on 15 Meters for a few days.

While propagation on 10 to the Pacific Northwest may not seem like much I recognize it as a marker that the days of summer propagation are numbered. Typically this doesn't happen until the last 2 weeks in August so it appears to be early this year. So like the Crocuses popping up in late February it doesn't do much for one aside from reminding us that better times are on the way.

As to what we can expect this Fall it looks to be much improved over last year and at the peak of Cycle 24. The 90 day mean SFI currently stands at 166. Last year at this time 90 day mean stood at 114. The 90 day Mean SFI for the peak of Solar Cycle 24 was 155.  The 90 Day Mean made a significant run-up during late Spring early Summer increasing 21 points. For the last 5 weeks the Daily SFI has been sliding. It hasn't dropped enough to impact the 90 and 81 Day Mean Values just yet, but if the decline continues those numbers will sag.

The rising phase of SC25 has its own characteristics. The solar flux rises rapidly for 4 to 8 weeks followed by an extended period of decline for 2 to 3 months. This makes it difficult to see the overall trend. It even faked out a number of heliophysicists who made the call that SC 25 had peaked in February 2023. The latest predictions call for SC 25 to peak at year-end 2023/2024. A few are calling for SC 25 to peak at mid-year 2024. It would be a pleasant surprise if the next surge kicks off a few weeks early, say by the first days of September. That would make a big impact of the conditions we can expect on 6 Meters this Fall."

The latest from Tamitha Skov: https://youtu.be/zjldvH1NYxg

Send your tips, reports, observations, questions and comments to k7ra@arrl.net .  When reporting observations, don't forget to tell us which mode you were operating.

For more information concerning shortwave radio propagation, see http://www.arrl.org/propagation and the ARRL Technical Information Service at:

http://arrl.org/propagation-of-rf-signals .

For an explanation of numbers used in this bulletin, see:

http://arrl.org/the-sun-the-earth-the-ionosphere .

Also, check this article from September, 2002 QST:

https://www.arrl.org/files/file/Technology/tis/info/pdf/0209038.pdf

An archive of past propagation bulletins is at: 

http://arrl.org/w1aw-bulletins-archive-propagation .

More good information and tutorials on propagation are at http://k9la.us/ .

Instructions for starting or ending email distribution of ARRL bulletins are at http://arrl.org/bulletins .

Sunspot numbers for August 10 through 16, 2023 were 83, 105, 61, 89, 85, 107, and 140, with a mean of 95.7  10.7 cm flux was 155.7, 152.8, 148.3, 150.4, 154, 158.1, and 160.1, with a mean of 154.2. Estimated planetary A indices were 7, 5, 8, 5, 5, 4, and 8, with a mean of 6. Middle latitude A index was 8, 6, 10, 7, 6, 7, and 10, with a mean of 7.7.