SB PROP @ ARL $ARLP020   
   ARLP020 Propagation de K7RA   
      
   ZCZC AP20   
   QST de W1AW   
   Propagation Forecast Bulletin 20  ARLP020   
   > From Tad Cook, K7RA   
   Seattle, WA  May 13, 2016   
   To all radio amateurs   
      
   SB PROP ARL ARLP020   
   ARLP020 Propagation de K7RA   
      
   There was a whopper of a geomagnetic storm on Mother's Day, May 8, when the   
   planetary A index reached 70. In Alaska, the college A index was 117. Aurora   
   was visible in North America well south of the northern tier states.   
      
   Average daily sunspot number dropped 15.6 points to 59.1 over the past week,   
   and average daily solar flux declined 3.1 points to 88.8.   
      
   Average daily planetary A index over the same period doubled from 11.3 to   
   22.6, and average daily mid-latitude A index rose 3.9 points to 14.6.   
      
   The latest prediction has planetary A index at 5 on May 13-14, then 8, 15, 12,   
   6, 5, 15 and 12 on May 15-21, 5 on May 22-23, 10 on May 24, 5 on May  25-27,   
   then 10, 25 and 10 on May 28-30, 5 on May 31 through June 1, 12 on June 2-3,   
   then 30, 32, 25, 15 and 8 on June 4-8, and 5 on June 9-10. Planetary A index   
   then rises to 25 on June 25, but that is a long way off.   
      
   Predicted solar flux is 95 and 97 on May 13-14, 100 on May 15-16, then 95, 93,   
   90 and 85 on May 17-20, 82 on May 21-22, 85 on May 23-25, 90 on May 26-30, 88   
   on May 31 through June 2, 85 on June 3-6, 90 on June 7-9, 95 on June 10-11,   
   then 90 and 85 on June 12-13, 82 on June 14-18, and 85 on June 19.   
      
   Petr Kolman, OK1MGW of the Czech Propagation Interest Group says the   
   geomagnetic field will be:   
      
   Quiet on May 16-17, 25-26   
   Mostly quiet on May 15, 22-24, 31, June 7-8   
   Quiet to unsettled on May 13-14, 18, 21, 27, 30   
   Quiet to active on May 19-20, 28-29, June 1-2, 3, 6   
   Active to disturbed on May (28), June 4-5   
      
   Increases in solar wind from coronal holes are expected on May 19-21, 28-29,   
   June 1-6   
      
   Parenthesis means lower probability of activity enhancement.   
      
   We missed it last week, but here is the latest update on our 3-month moving   
   average. According to our numbers, Solar Cycle 24 peaked with a sunspot number   
   of 148.2 in the three months centered on March 2014.   
      
   Beginning with the 3 months centered on January, 2015, the 3-month moving   
   average of daily sunspot numbers was 98.2, 78.1, 68.2, 72.4, 77.7, 76.3, 69.1,   
   67.5, 64.5, 64.6, 58.5, 55.4, 53.5, 49 and 45.3. The numbers reflect the   
   steady decline of Solar Cycle 24.   
      
   According to http://1.usa.gov/1HOVlDP it looks like the next solar minima   
   should be in 2019. These are international sunspot numbers, but the sunspot   
   numbers we report in this bulletin are from the NOAA Space Environment Service   
   Center, ftp://ftp.swpc.noaa.gov/pub/indices/DSD.txt .   
      
   David Moore sent this piece from Science Daily about solar wind:   
      
   https://www.sciencedaily.com/releases/2016/05/160511102655.htm   
      
   Now here is a surprising and counter-intuitive assertion. http:/   
   bit.ly/1rJxxki claims "When sunspots are minimal, the solar magnetic field is   
   at a maximum."   
      
   As mentioned in last week's bulletin, Carl, K9LA offers the W6ELProp   
   installation file if you have trouble downloading it from www.qsl.net/w6elprop.   
      
   Note that the latest version of W6ELProp is Version 2.70, which was in the   
   2002 time frame. Thus it is likely that Shel, W6EL never checked it out with   
   newer operating systems like Vista and Windows 7, 8 and 10. Shel, W6EL became   
   a Silent Key in April 2015, and as far as Carl is aware the source code for   
   W6ELProp was never released to anyone.   
      
   If anyone has successfully installed W6ELProp on a PC using Vista or Windows   
   7, 8 or 10, Carl would like to hear from you. Carl can be reached via email   
   at, k9la@arrl.net.   
      
   Actually I have run it successfully on Windows 7 and 10, but Carl pointed out   
   that the Maps feature doesn't work.   
      
   The Solar Plotting Utility mentioned in past bulletin doesn't run on Windows 7   
   or 10, but that is easily solved by running Windows Xp as a virtual machine   
   within the newer Windows versions.   
      
   In Windows 10 it is also possible to run older programs in Compatibility Mode.   
      
   If you would like to make a comment or have a tip for our readers, email the   
   author at k7ra@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 the numbers used in this bulletin, see htt   
   ://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 May 5 through May 11 were 55, 56, 51, 42, 68, 70, and 72,   
   with a mean of 59.1. 10.7 cm flux was 87.1, 89.6, 88, 85.6, 88.5, 88.7, and   
   93.9, with a mean of 88.8. Estimated planetary A indices were 8, 15, 10, 70,   
   33, 16, and 6, with a mean of 22.6. Estimated mid-latitude A indices were 7,   
   12, 9, 32, 21, 15, and 6, with a mean of 14.6.   
      
   NNNN   
   /EX   
      
   )\/(ark   
      
   Always Mount a Scratch Monkey   
      
   ... "What am I doing here?" - junior cavalryman in General Custer's ranks.   
   ---   
    * Origin:  (1:3634/12.73)