[SFDXA] ARLP036 Propagation de K7RA

[WILLIAM MARX]

> SB PROP @ ARL $ARLP036
> ARLP036 Propagation de K7RA
> 
> ZCZC AP36
> QST de W1AW  
> Propagation Forecast Bulletin 36  ARLP036
> From Tad Cook, K7RA
> Seattle, WA  September 3, 2021
> To all radio amateurs 
> 
> SB PROP ARL ARLP036
> ARLP036 Propagation de K7RA
> 
> Solar activity is on the upswing this week.  Average daily sunspot
> numbers increased from 21.7 to 50.6, with a high of 77 last
> Saturday, August 28.  Average daily solar flux rose from 78.5 to 88.
> 
> Average daily planetary A index increased from 4.7 to 9.6, and
> average daily middle latitude A index went from 5.7 to 10.7.
> Geomagnetic activity peaked on August 27 and 28 due to a coronal
> mass ejection.
> 
> New sunspot regions appeared on August 26 and 27, and on September 2
> Spaceweather.com reported "New Sunspot, Rapidly Growing" to announce
> the emergence of AR2863.
> 
> Predicted solar flux looks promising, particularly after
> mid-September, at 85 and 82 on September 3 and 4, 80 on September 5
> and 6, 78 on September 7, 75 on September 8 to 10, 80 on September
> 11 to 14, 85 on September 15, 90 on September 16 to 30, 85 on
> October 1, and 80 on October 2 to 10.  Flux values rise to 90 again
> after October 12 in this forecast from September 2.
> 
> Predicted planetary A index is 8, 5, 10 and 8 on September 3 to 6, 5
> on September 7 to 10, then 10 and 8 on September 11 and 12, 5 on
> September 13 to 20, 8 on September 21, 5 on September 22 to 25, then
> a big jump to 25, 8, 18, 8, and 12 on September 26 to 30, and back
> to 5 on October 1 to 7, then 10 and 8 on October 8 and 9.
> 
> Geomagnetic activity forecast for the period September 3 to 29,
> 2021, from F. K. Janda, OK1HH.
> 
> "Geomagnetic field will be
> Quiet on September 7 and 8, 10, 14 and 15, 17 and 18, 28 and 29
> Quiet to unsettled on September 4 and 5, 13, 16, 19, 22, 25, 27
> Quiet to active on September 3, 6, 9, 11 and 12, 20 and 21, 26
> Unsettled to active on September 23 and (- 24)
> Active to disturbed, nothing predicted
> 
> Remarks:
> - Parenthesis means lower probability of activity enhancement.
> - The situation is confusing, the configuration of active regions
> and coronal holes is variable, so this time it is not possible to
> make a so-so reliable forecast.  Here and there it happens before
> solar activity rises.
> - F. K. Janda will travel next week, therefore next forecast will be
> compiled on September 16."
> 
> The autumnal equinox will be on Wednesday, September 22 in the
> Northern Hemisphere, always a welcome event for HF propagation.
> Solar flux is forecast to be higher at that time, also a good sign.
> 
> 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.
> 
> 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 26 through September 1, 2021 were 47, 73,
> 77, 44, 41, 37, and 35, with a mean of 50.6.  10.7 cm flux was 88.6,
> 89.5, 89.9, 88.7, 90.6, 84.4, and 84.2, with a mean of 88.
> Estimated planetary A indices were 6, 20, 14, 8, 7, 7, and 5, with a
> mean of 9.6.  Middle latitude A index was 6, 19, 17, 9, 9, 9, and 6,
> with a mean of 10.7.
> NNNN
> /EX