[SFDXA] ARLP034 Propagation de K7RA

[Bill]

> SB PROP @ ARL $ARLP034
> ARLP034 Propagation de K7RA
> 
> ZCZC AP34
> QST de W1AW  
> Propagation Forecast Bulletin 34  ARLP034
> From Tad Cook, K7RA
> Seattle, WA  August 25, 2023
> To all radio amateurs 
> 
> SB PROP ARL ARLP034
> ARLP034 Propagation de K7RA
> 
> Five new sunspot groups emerged this week, one on August 17, another
> August 18, two more on August 21 and another on August 22.
> 
> Average daily sunspot numbers rose slightly, while average daily
> solar flux declined. Average daily sunspot numbers went from 95.7 to
> 105.9 and average daily solar flux declined from 154.2 to 149.4.
> 
> No big geomagnetic events this week, and average daily planetary A
> index changed from 6 to 8.4 while average daily middle latitude
> index went from 7.7 to 10.1.
> 
> Predicted solar flux is 145 on August 25-26, 150 on August 27, 155
> on August 28-29, 160 on August 30-31, then 165, 163 and 160 on
> September 1-3, 162 on September 4-5, 158 on September 6-7, then 160
> and 162 on September 8-9, 158 on September 10-11, 155 on September
> 12, 152 on September 13-15, 153 on September 16-18, 155 on September
> 19, and 158 on September 20-23, 162 on September 24-25, 165 on
> September 26-28, then 163 and 160 on September 29-30.
> 
> Predicted planetary A index is 8 on August 25, then 5, 10 and 8 on
> August 26-28, 5 on August 29 through September 5, then 10, 8 and 8
> on September 6-8, 5 on September 9-13, 12 on September 14, 10 on
> September 15-17, and 5 on September 18 through the end of the month.
> 
> Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
> Ionosphere August 25-31, 2023 from F. K. Janda, OK1HH.
> 
> Although solar activity has been rated as low over the last seven
> days, let's not be misled by an assessment based mainly on the
> number and importance of flares. Solar activity continues to
> increase toward the peak of cycle 25, expected in two years.
> Projected into the highest usable ionospheric F2 layer frequencies,
> this means that we may finally be able to look forward to a wide
> opening of the ten-meter band for DX shortwave contacts. If it
> occurs during this fall, we can expect the 25th cycle maximum to be
> quite high after all.
> 
> It was pretty quiet over the weekend as all eight sunspot groups had
> stable magnetic fields. Despite another large sunspot appearing in
> the meantime, apparently magnetically connected to another sunspot
> on the other side of the solar equator, there was still not much
> going on. Only the M1.1 0 class solar flare on August 22 at 2304 UTC
> was an exception. But although it lasted long enough to carry a CME
> out of the solar atmosphere, it evidently did not.
> 
> On August 23, a filament erupted near the southwest limb of the Sun.
> If it envelops the Earth, it would likely not happen until August
> 27, with a possible G1 class storm.
> 
> Max White, M0VNG sent this about solar wind: https://bit.ly/3YQToa7
> 
> Reader Jeremy Gill of Seattle, WA contributed this article on aurora
> and the ionosphere: https://bit.ly/44sRGgh .
> 
> Warnings about solar activity, some a bit shrill:
> 
> https://bit.ly/3qHy6za  https://bit.ly/3YLsoc 
> 
> https://bit.ly/3QNx8w3  https://bit.ly/3OJRCTP
> 
> A new video from Tamitha Skov:  https://youtu.be/lU8s7RmlSfE
> 
> Send your tips, reports, observations, questions and comments to
> k7ra at 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 17 through 23, 2023 were 135, 112, 104,
> 93, 102, 96, and 99, with a mean of 105.9.  10.7 cm flux was 151.9,
> 150.6, 150.6, 146.3, 148.7, 150.9, and 147, with a mean of 149.4.
> Estimated planetary A indices were 8, 11, 8, 11, 9, 8, and 4, with a
> mean of 8.4.  Middle latitude A index was 10, 14, 8, 12, 10, 12, and
> 5, with a mean of 10.1.
> NNNN
> /EX