SB PROP @ ARL $ARLP042   
   ARLP042 Propagation de K7RA   
      
   ZCZC AP42   
   QST de W1AW   
   Propagation Forecast Bulletin 42  ARLP042   
   > From Tad Cook, K7RA   
   Seattle, WA  October 16, 2015   
   To all radio amateurs   
      
   SB PROP ARL ARLP042   
   ARLP042 Propagation de K7RA   
      
   The Australian Space Forecast Centre issued a geomagnetic disturbance warning   
   at 2345 UTC on October 15. The alert said "The continued strengthening of the   
   solar wind stream due to coronal hole effect may lead to isolated periods of   
   minor geomagnetic storms on 16 October."   
      
   Sunspot numbers over the past week (October 8-14) were nearly the same as the   
   previous seven days. Average daily sunspot numbers went from 37 to 36.9, and   
   average daily solar flux dropped from 93.8 to 87.5   
      
   Just as in previous solar cycles, geomagnetic indicators are high as the cycle   
   trends downward after the peak. Go to the bottom of the page at    
   ttp://www.wm7d.net/hamradio/solar/ and note the graph for Ap (planetary A   
   index) progression. If you look at the graph just above that for solar flux,   
   see how the Ap index is high after the peak of solar flux or sunspot numbers.   
      
   From last week to this week, average daily planetary A index went from 24.3 to   
   25.1, and average mid-latitude A index moved from 15.7 to 17.6.   
      
   Predicted solar flux is 105 on October 16, 110 on October 17, 120 on October   
   18-21, 115 on October 22-23, 120 on October 24, 125 on October 25-26, then   
   130, 120 and 110 on October 27-29, 100, 90 and 85 on October 30 through   
   November 1, 80 on November 2-6, 85 on November 7-8 and 90 on November 9-11.   
   Solar flux then rises to 130 on November 23 and drops below 100 after November   
   26.   
      
   Predicted planetary A index is 18, 15 and 12 on October 16-18, 8 on October   
   19-20, 5 on October 21-27, then 8, 12 and 10 on October 28-30, 8 on October 31   
   through November 2, 20 on November 3, 15 on November 4-5, then 12, 8, 20, 15   
   and 18 on November 6-10, 20 on November 11-12, 15 on November 13 and 8 on   
   November 14-18.   
      
   OK1MGW of the Czech Propagation Interest Group says to expect a quiet to   
   active geomagnetic field on October 16-17, quiet to unsettled on October 18,   
   mostly quiet October 19-20, quiet to unsettled October 21, quiet on October   
   22-26, mostly quiet October 27, quiet to unsettled October 28-30, quiet to   
   active October 31 through November 1, active to disturbed November 2-5, quiet   
   to unsettled November 6, quiet to active November 7-9, and quiet to unsettled   
   November 10-11.   
      
   David Moore sent this: "The Sun has sprung a leak. A hole in the topmost layer   
   of the Sun and its magnetic field, the size of 50 Earths, is letting loose an   
   ultra-fast solar wind that has kicked off several nights of auroras down on   
   Earth." See https://shar.es/1uGMJ5 .   
      
   Check http://bit.ly/1jGiC66 for a picture of that huge coronal hole. Note you   
   can click on the image to zoom in.  The white lines represent magnetic lines   
   of force. You can check current images of   
   the Sun at various wavelengths at http://sdowww.lmsal.com/suntoday_v2/ .   
      
   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 http://   
   rrl.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/.   
      
   My own 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/1VOqf9B and http://bit.ly/1DcpaC5 .   
      
   Click on "Download this file" to download the archive, and ignore the security   
   warning about file format. Pop-up blockers may suppress the download.   
      
   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 8 through 14 were 24, 11, 22, 36, 51, 58, and 56,   
   with a mean of 36.9. 10.7 cm flux was 79.7, 81.2, 81.4, 84.6, 89.1, 95.6, and   
   100.7, with a mean of 87.5. Estimated planetary A indices were 56, 26, 12, 12,   
   22, 25, and 23, with a mean of 25.1. Estimated mid-latitude A indices were 41,   
   15, 9, 8, 16, 18, and 16, with a mean of 17.6.   
      
   NNNN   
   /EX   
      
   )\/(ark   
      
   ... If I can't EAT fried foods what CAN I do with them?   
   ---   
    * Origin:  (1:3634/12.73)