QST de W1AW  
Propagation Forecast Bulletin 34  ARLP034
>From Tad Cook, K7RA
Seattle, WA  August 20, 2021
To all radio amateurs 

SB PROP ARL ARLP034
ARLP034 Propagation de K7RA

Weak solar activity persists, but with just one spotless day in the
current reporting week, August 12 to 18, on Friday, August 13.  Last
week we reported four days with no sunspots in the previous seven
days.

Average daily sunspot number increased from 9.9 last week to 17.7
during this week.

Solar flux was the same, with the average inching from 73.7 to 73.8.

Geomagnetic indicators were also stable.  Average planetary A index
was 6.1, compared to 6.3 last week.  Average middle latitude A index
moved from 7.6 to 7.

Predicted solar flux is 75 on August 20, 73 on August 21 to 23, 72
on August 24 to 26, 73 on August 27 to 29, 74 on August 30 through
September 1, 73 on September 2 to 11, 74 on September 12, 73 on
September 13 to 17, 72 on September 18, and 73 on September 19 to
25.

Predicted planetary A index is 5 on August 20, then 8, 8, 10, 14, 12
and 8 on August 21 to 26, 5 on August 27 through September 1, then 8
and 12 on September 2 and 3, 5 on September 4 to 10, 8 on September
11 to 13, 5 on September 14 to 18, then 8, 12 and 8 on September 19
to 21, and 5 on September 22 to 28.

On August 14 Spaceweather.com reported that there were no sunspots,
and that so far in 2021 there were 56 days with no spots.  'That
might sound like a lot, but it is in fact a sharp reduction from
hundreds of spotless days observed in 2019 and 2020.  Despite
today's blank sun, solar activity is intensifying compared to
previous years.'

Geomagnetic activity forecast for the period August 20 til September
14, 2021 from OK1HH, who has returned from his hike in the mountains
of the Czech Republic:

'Geomagnetic field will be
Quiet August 20 and 21, 28, September 1, 5, 10, 14
Quiet to unsettled August 22, 25 to 27, 31, September 2, 4, 6 to 9
Quiet to active August 30, September 3, (11 to 13)
Unsettled to active August (23 and 24, 29)
Active to disturbed, Nothing predicted
 
Remarks:
- Parenthesis means lower probability of activity enhancement.
- The predictability of changes is very low because there are not
enough indications.'

Ken Brown, N4SO reported hearing a new 10 meter beacon, N5TIT/B on
28.209 MHz.

Signal was weak, and the path was 520 miles.

I've noted that the relatively low solar activity has depressed 10
meter signals, and my practice of using remote SDR receivers to hunt
for beacons turns up little activity lately.

At the end of July I spent 8 days in hospital for neurosurgery, and
managed to use kiwisdr.com/public/ to hunt for 10 meter beacons, and
wrote ARLP031 that week as well.  I used the list at
https://www.qsl.net/wj5o/bcn.htm to help identify them, and sent
reports to the beacon owners.

The latest from WX6SWW:

https://youtu.be/GdI-itUhKec

For more information concerning shortwave radio propagation, see
www.arrl.org/propagation and the ARRL Technical Information
Service at arrl.org/propagation-of-rf-signals.  For an
explanation of numbers used in this bulletin, see
arrl.org/the-sun-the-earth-the-ionosphere.

An archive of past propagation bulletins is at
arrl.org/w1aw-bulletins-archive-propagation.  More good
information and tutorials on propagation are at k9la.us/.

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

Sunspot numbers for August 12 through 18, 2021 were 11, 0, 47, 23,
14, 13, and 16, with a mean of 17.7.  10.7 cm flux was 73.6, 72.9,
72.6, 74.6, 74.4, 73.1, and 75.3, with a mean of 73.8.  Estimated
planetary A indices were 4, 6, 5, 10, 7, 5, and 6, with a mean of
6.1 Middle latitude A index was 6, 9, 4, 13, 8, 7, and 6, with a
mean of 7.6.