[SFDXA] ARLP050 Propagation de K7RA

[Bill M]

> SB PROP @ ARL $ARLP050
> ARLP050 Propagation de K7RA
> 
> ZCZC AP50
> QST de W1AW  
> Propagation Forecast Bulletin 50  ARLP050
> From Tad Cook, K7RA
> Seattle, WA  December 22, 2017
> To all radio amateurs 
> 
> SB PROP ARL ARLP050
> ARLP050 Propagation de K7RA
> 
> During the recent reporting week (December 14 to 20) the first six
> days had zero sunspots. On December 20 one new sunspot group
> appeared (2692) with a sunspot number of 16. The average daily
> sunspot number decreased from 6.9 during the previous seven days to
> 2.3.
> 
> Average solar flux increased from 71 to 71.5, average planetary A
> index went from 7.4 to 9.4, and mid-latitude A index increased from
> 5.5 to 6.1.
> 
> Predicted solar flux for the next 45 days is 75 on December 22 to
> 28, 74 on December 29 through January 1, 76 on January 2 to 5, 74 on
> January 6 to 13, 72 on January 14 to 19, 74 on January 20 to 28, 76
> on January 29 through February 1, and 74 on February 2 to 4.
> 
> Predicted planetary A index is 8 on December 22 and 23, 5 on
> December 24 to 26, 10 and 8 on December 27 and 28, 5 on December 29
> and 30, then 10, 25, 15 and 10 on December 31 through January 3, 5
> on January 4 to 6, then 10, 12 and 8 on January 7 to 9, 5 on January
> 10 to 12, 22 on January 13 and 14, then 20, 16, 10 and 8 on January
> 15 to 18, 5 on January 19 to 22, 12 and 8 on January 23 and 24, 5 on
> January 25 and 26, then 10, 25, 15 and 10 on January 27 to 30, 5 on
> January 31 through February 2, 10 on February 3 and 12 on February
> 4.
> 
> F.K. Janda, OK1HH sent this:
> 
> "Geomagnetic activity forecast for the period December 22 to January
> 17, 2018
> 
> Geomagnetic field will be: 
> Quiet on December 23, 26, January 5 and 6, 11 
> Mostly quiet on December 22, 24, 30, January 4, 10, 15 
> Quiet to unsettled on December 25, January 7, 17 
> Quiet to active on December 27 to 29, 31, January 2 and 3, 8 and 9,
> 12, 14, 16 Active to disturbed on January 1, 13
> 
> Amplifications of the solar wind from coronal holes are expected on
> December (24 to 28,) January 1 to 3, (6 to 8,) 10 to 13
> 
> Remark: 
> - Parenthesis means lower probability of activity enhancement." 
> 
> Kent Trimble, K9ZTV of Jefferson City, Missouri helpfully pointed
> out that in last week's bulletin ARLP049 I wrote JT8 when I should
> have written FT8. That line should read "FT8 seems to have taken the
> amateur radio service by storm in recent months, with an amazing
> rate of acceptance due to its weak signal capabilities and easy
> implementation."
> 
> Not sure I trust the source, but this article has a number of
> interesting references:
> 
> http://bit.ly/2kxhgxN 
> 
> The article mentions that in 2017 there have been 96 days (27
> percent) with no sunspots, but as of this week that number is 101
> days, or 28 percent, according to Spaceweather.com. The same list
> shows that in 2009, 71 percent of the year had no sunspots.
> 
> Tamitha Skov posts great videos of her space weather predictions on
> YouTube, but they are usually after my weekly bulletin is posted.
> 
> Check for her latest at:
> 
> https://www.youtube.com/user/SpWxfx 
> 
> I like the descriptions of space weather phenomena in this article: 
> 
> http://bit.ly/2BQsBAq 
> 
> For more information concerning radio propagation, see 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/.
> 
> 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 December 14 to 20, 2017 were 0, 0, 0, 0, 0, 0,
> and 16, with a mean of 2.3. 10.7 cm flux was 72.1, 71.7, 71.3, 71,
> 71.6, 68.8, and 74.2, with a mean of 71.5. Estimated planetary A
> indices were 5, 5, 4, 24, 17, 6, and 5, with a mean of 9.4.
> Estimated mid-latitude A indices were 2, 3, 3, 16, 12, 4, and 3,
> with a mean of 6.1.
> NNNN
> /EX