[SFDXA] ARLP021 Propagation de K7RA

[Bill]

> SB PROP @ ARL $ARLP021
> ARLP021 Propagation de K7RA
> 
> ZCZC AP21
> QST de W1AW  
> Propagation Forecast Bulletin 21  ARLP021
> From Tad Cook, K7RA
> Seattle, WA  May 22, 2015
> To all radio amateurs 
> 
> SB PROP ARL ARLP021
> ARLP021 Propagation de K7RA
> 
> Sunspot numbers drifted below 100 over the past week (May 14 to 20),
> and so the average daily sunspot number declined from 146.9 over the
> previous seven days to 92.1 in the recent period.  Average daily
> solar flux dropped from 156.3 to 123.3.
> 
> You can see the decline in solar flux in addition to the decline in
> predicted numbers by downloading the spreadsheet at
> http://bit.ly/1KQGbRm which shows us the daily readings and the
> shifting 45-day predictions from NOAA/USAF.
> 
> From that spreadsheet you can see that the predicted solar flux is
> 100 on May 22 and 23, 95 on May 24 to 28, 105 on May 29 and 30, 110
> on May 31, 115 on June 1, 120 on June 2 and 3, 125 on June 4, 130 on
> June 5 and 6, 120 on June 7 to 12, 110, 115, 105 and 95 on June 13
> to 16, 90 on June 17 to 19, 95 on June 20, and 105 on June 21 to 26.
> This value peaks again at 130 on July 2.  ARRL Field Day is June 27
> and 28, 2015 when predicted solar flux is 110 and 115, and predicted
> planetary A index is 5.
> 
> Predicted planetary A index is 5 on May 22 to 24, 8 on May 25 and
> 26, 5 on May 27 and 28, 8 on May 29 and 30, 5 on May 31 to June 1,
> 15 and 10 on June 2 and 3, 5 on June 4 to 6, 12 on June 7, 25 on
> June 8 and 9, 12 on June 10, 5 on June 11 and 12, then 8, 15 and 12
> on June 13 to 15, and 5 on June 16 to 24.  You can see these
> predicted values and more, going out 45 days, by downloading the
> spreadsheet at http://bit.ly/1IBXtnG .
> 
> OK1HH predicts geomagnetic activity will be quiet on May 22 and 23,
> mostly quiet May 24, quiet to active May 25, quiet May 26 and 27,
> quiet to unsettled May 28 and 29, mostly quiet May 30, quiet to
> unsettled May 31, mostly quiet June 1, active to disturbed June 2,
> quiet to active June 3, mostly quiet June 4 and 5, quiet to
> unsettled June 6, quiet to active June 7 to 9, disturbed June 10 and
> 11, mostly quiet June 12, quiet June 13, quiet to active June 14,
> active to disturbed June 15, quiet to active June 16, and quiet on
> June 17.
> 
> OK1HH says the reliability of his predictions are reduced (although
> I don't know why) and that he sees a possible increase in solar wind
> on May 22 and 23, May 30, June 2 and 3, June 8 and 9 and June 12.
> He puts parenthesis around dates he is particularly uncertain about,
> and he has those around May 22 and 23 for both the quiet conditions
> prediction and the increase in solar wind.  The two seem mutually
> exclusive to me, but since May 22 and 23 is today and tomorrow, we
> should know soon enough.  He also has parens around the increase in
> solar wind for June 8 and 9.
> 
> Jon Jones, N0JK of Kansas shares this news about events on May 18:
> 
> "An unexpected aurora event occurred May 18.  Around 2245z aurora
> allowed stations in Minnesota, North Dakota, Illinois, Iowa,
> Michigan and southern Canada to make 6 meter contacts.  I heard K9KU
> in Wisconsin and KC0CF in Iowa on 6 meter aurora in Kansas.  The
> aurora was due to unsettled solar wind which sparked a G2-class
> geomagnetic storm."
> 
> For more information concerning radio propagation, see the ARRL
> Technical Information Service at
> http://arrl.org/propagation-of-rf-signals.  For an explanation of
> the 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/.
> 
> Archives of the NOAA/USAF daily 45 day forecast for solar flux and
> planetary A index are in downloadable spreadsheet format at
> http://bit.ly/1IBXtnG and http://bit.ly/1KQGbRm .
> 
> Click on "Download this file" to download the archive and ignore the
> security warning about the file format.
> 
> 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 May 14 through 20 were 126, 113, 103, 75, 83,
> 84, and 61, with a mean of 92.1.  10.7 cm flux was 145.1, 136.5,
> 131, 119.6, 115, 110.3, and 105.6, with a mean of 123.3.  Estimated
> planetary A indices were 10, 8, 6, 6, 16, 17, and 7, with a mean of
> 10.  Estimated mid-latitude A indices were 9, 7, 7, 6, 15, 14, and
> 10, with a mean of 9.7.
> NNNN
> /EX