[SFDXA] ARLP041 Propagation de K7RA

[Bill Marx]

> SB PROP @ ARL $ARLP041
> ARLP041 Propagation de K7RA
> 
> ZCZC AP41
> QST de W1AW  
> Propagation Forecast Bulletin 41  ARLP041
> From Tad Cook, K7RA
> Seattle, WA  October 12, 2018
> To all radio amateurs 
> 
> SB PROP ARL ARLP041
> ARLP041 Propagation de K7RA
> 
> Last week this bulletin reported a return of sunspot activity on
> September 29 after a 16 day absence from September 13-28, but the
> new activity only lasted 6 days. As of Thursday night (October 11)
> we are now at 7 days with no sunspots visible.
> 
> Average daily sunspot number declined from 9.6 to 1.6, while average
> daily solar flux rose slightly from 68.4 to 68.9.
> 
> Average planetary A index increased from 7.7 to 14.1, while
> mid-latitude A index rose from 6.1 to 10.3.
> 
> Predicted solar flux is 71 on October 12, 70 on October 13-18, 69 on
> October 19 through November 25.
> 
> Predicted planetary A index is 8, 5, 12 and 8 on October 12-15, 5 on
> October 16-17, 12 on October 18-19, then 14, 8 and 12 on October
> 20-22, 8 on October 23-25, 10 on October 26, 5 on October 27 through
> November 2, then 22 and 35 on November 3-4, 15 on November 5-6, then
> 10, 8, 5, 10 and 8 on November 7-11, 5 on November 12-13, then 10,
> 25, 14, 8 and 12 on November 14-18, 8 on November 19-21, 10 on
> November 22 and 5 on November 23-25.
> 
> Conditions should continue at marginal levels because of weak solar
> activity.
> 
> I keep checking the weekly Preliminary Report and Forecast from SWPC
> (see ftp://ftp.swpc.noaa.gov/pub/warehouse/2018/WeeklyPDF/ ) because
> once a month they update solar cycle predictions for smoothed
> sunspot number and smoothed 10.7 cm solar flux.
> 
> For the past several years (at least back to early 2015) the
> projection ended in December 2019. It is widely believed that this
> cycle (Solar Cycle 24) should reach solar minimum in 2020, so I keep
> checking for projections that go past 2019, but so far nothing new
> is posted.
> 
> You can see the latest projection in a recent bulletin on pages
> 10-11 at
> ftp://ftp.swpc.noaa.gov/pub/warehouse/2018/WeeklyPDF/prf2249.pdf .
> 
> It shows the predicted smoothed sunspot number for October 2018 at
> 11.
> 
> Because the smoothed sunspot number is averaged over a year, this
> means that about half of the current average is made up of real
> sunspot numbers averaged over the past 6 months and the other part
> of the average is made up of predicted sunspot numbers over the next
> 6 months. So as you look at the averages, for every month you look
> back, you see the results of more and more real sunspot numbers.
> 
> Note that in July 2018 the projected smoothed sunspot number is only
> 1. This may change as time goes on and more of actual sunspot
> numbers are figured into the average.
> 
> More detail on smoothed sunspot numbers:
> 
> http://www.sidc.be/silso/node/52
> 
> http://www.astrosurf.com/luxorion/qsl-ssn-history-voacap.htm
> 
> Geomagnetic activity forecast for the period October 12 to November
> 07, 2018 from F.K. Janda, OK1HH.
> 
> "Geomagnetic field will be:
> Quiet on October 13, 16, 29-31, on November 1
> Quiet to unsettled on October 14-15, 17, 27, 31
> Quiet to active on October 12, 20, 22-26, on November 2, 7
> Unsettled to active on October 18, 21, 28, on November 5-6
> Active to disturbed on October 19, on November 3-4
> 
> "Solar wind will intensify on October 12-13, (14,) 17-20, (27-28,) on
> November 2-5
> 
> "Remark: - Parenthesis means lower probability of activity
> enhancement."
> 
> If you would like to make a comment or have a tip for our readers,
> email the author at, k7ra at arrl.net .
> 
> For more information concerning radio propagation, see the ARRL
> Technical Information Service web page 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/.
> 
> Monthly propagation charts between four USA regions and twelve
> overseas locations are at http://arrl.org/propagation.
> 
> Instructions for starting or ending email distribution of ARRL
> bulletins are at http://arrl.org/bulletins.
> 
> Sunspot numbers for October 4 through 10, 2018 were 11, 0, 0, 0, 0,
> 0, and 0, with a mean of 1.6. 10.7 cm flux was 67.2, 68.7, 68.6,
> 69.5, 68.8, 69.5, and 69.8, with a mean of 68.9. Estimated planetary
> A indices were 4, 9, 6, 24, 21, 17, and 18, with a mean of 14.1.
> Estimated mid-latitude A indices were 4, 8, 5, 13, 16, 14, and 12,
> with a mean of 10.3.
> NNNN
> /EX