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 15, 2015   
   To all radio amateurs   
      
   SB PROP ARL ARLP020   
   ARLP020 Propagation de K7RA   
      
   This week our quiet Sun came alive, and now the visible solar disc   
   is crowded with sunspots. On Monday, May 11 the SESC daily sunspot   
   number rose to 188. That is the highest sunspot number since January   
   30, when it was 193. Prior to that we have to go back to November   
   17, 2013 to find a higher sunspot number. It was 282 on that day,   
   which was way over on the other side of the peak in cycle 24, which   
   happened around February and March of 2014.   
      
   The average daily sunspot number increased 86 points from the   
   previous week to 146.9 for the current period, May 7-13. Over the   
   same periods the average daily solar flux rose from 115.4 to 156.3.   
      
   At 2324 UTC on May 12, the Australian Space Forecast Centre issued a   
   geomagnetic warning: "Increased geomagnetic activity expected due to   
   high speed coronal hole wind stream for 13 May 2015."   
      
   Indeed, the prediction was correct, and the planetary A index for   
   May 13 was 45, while the college A index reached 63.   
      
   The predicted planetary A index is 12, 10, 20 and 15 on May 15-18,   
   then 5 on May 19-28, 8 on May 29-30, 5 on May 31, then 8, 15 and 10   
   on June 1-3, 5 on June 4-6, 12 on June 7, 25 on June 8-9, and 12 and   
   8 on June 10-11.   
      
   Predicted solar flux is 140 on May 15-16, then 135, 125, 115 and 105   
   on May 17-20, then 100, 105 and 115 on May 21-23, 110 on May 24-27,   
   115 on May 28, 120 on May 29-31, 130 on June 1, 140 on June 2-4,   
   then peaking at 160 for the near term on June 9.   
      
   The OK1HH geomagnetic activity forecast sees quiet to active   
   conditions May 15-17, active to disturbed May 18, quiet to unsettled   
   May 19, quiet May 20-23, mostly quiet May 24, quiet to unsettled May   
   25, quiet May 26-27, mostly quiet May 28, quiet to unsettled May 29,   
   quiet to active May 30, quiet to unsettled May 31, active to   
   disturbed June 1, mostly quiet June 2-4, quiet June 5-6, quiet to   
   active June 7, active to disturbed June 8-9, and disturbed June 10.   
      
   The NASA Solar Cycle Prediction remains the same, but yesterday the   
   date was updated from January 14 to May 14, 2015 at   
   http://solarscience.msfc.nasa.gov/predict.shtml . That is all that   
   changed. There is no new forecast.   
      
   The Washington Post weather blog ran this article about sunspot   
   2339:   
      
   http://www.washingtonpost.com/blogs/capital-weather-gang/wp/2015   
   05/12/giant-sunspot-pointed-at-earth-solar-wind-sparking-high-latitude-aurora/   
   ..   
      
   Dave Pedersen, PJ4VHF/N7BHC reports a 2 meter CW reception on   
   Bonaire of the D4C/B beacon at Cape Verde via tropospheric ducting.   
   Bonaire is just north of Venezuela in the Caribbean and Cape Verde   
   is off the coast of Africa, west of Senegal, a distance of 2,917   
   miles.   
      
   This was on May 6, 2015 at 0100-0230 UTC on 144.436 MHz, using a   
   Kenwood TS-2000 and two 13 element Yagis at the receive site. The   
   beacon on the other end runs 20 watts. Dave reports the reception   
   was verified by Andre, HB9DUR, the beacon operator.   
      
   Dave also sent an audio/video file showing the receiver, and the CW   
   signal is clearly heard. I posted it at http://bit.ly/1cD9qMa and   
   you should click on "Download This File."   
      
   Dave writes, "Fred NP2X and I were alerted by the Hepburn maps that   
   tropospheric cutting looked promising last week. We started   
   listening on 2m from the previous Saturday, May 2. The previous week   
   had seen many days of very good ducting all across the eastern   
   Caribbean with LP4 repeaters pinning the S meters here on Bonaire   
   for several days. Jamaica came in 60 over 9 on Saturday evening but   
   there were no stations on the repeater. We have experienced high   
   winds for the last 2 weeks here on Bonaire, gusting over 35 mph for   
   many days. I had parked my VHF array pointing west for minimum wind   
   resistance. Tuesday evening I was doing some paperwork in the shack,   
   and rotated the beams back east at 9pm local (0100 UTC) to prepare   
   for listening all night. To my amazement, I started copying CW while   
   the beam was still 30 degrees off the D4C bearing."   
      
   Nice job, Dave, and thanks for that excellent report.   
      
   Jeff, N8II reports that conditions were excellent on 15 meters on   
   Saturday, May 9 into Central and West Asia at 1400-1500 UTC during   
   the CQ M Russian contest.   
      
   Tomas Hood, NW7US sent a report and a link to a video of the X2.7   
   flare on May 5. Tomas wrote, "An impulsive, major solar flare   
   reaching X2.7 erupted at 22:05 UTC (5:05 p.m. CDT) and ended at   
   22:15 UTC, peaking at 22:11 UTC. This is the most intense flare so   
   far, in year 2015.   
      
   "A video compilation of this magnitude X2.7 solar flare, 'Sun   
   Unleashes Most Powerful Flare of 2015 (as of May 5),' may be viewed   
   at http://g.nw7us.us/x2p7sf050515   
      
   "This X2.7-level flare produced a level R3 (Strong) shortwave radio   
   blackout on the sunlit side of Earth, which was over the Pacific   
   region.   
      
   "A coronal mass ejection was associated with this flare. The flare   
   originated in Sunspot Active Region NOAA 2339.   
      
   "In addition, the flare produced a two-minute radio burst, heard as   
   a roar of static from shortwave receivers on Pacific isles and   
   western parts of North America. A radio burst of this kind is   
   generally short-lived, but can cause interference for radar, GPS,   
   and satellite communications."   
      
   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://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 7 through 13 were 131, 134, 136, 134, 188,   
   170, and 135, with a mean of 146.9. 10.7 cm flux was 146.6, 149.8,   
   154.5, 159.9, 163, 163.2, and 157, with a mean of 156.3. Estimated   
   planetary A indices were 6, 6, 7, 11, 15, 15, and 45, with a mean of   
   15. Estimated mid-latitude A indices were 6, 7, 8, 12, 15, 16, and   
   25, with a mean of 12.7.   
   NNNN   
   /EX   
      
   )\/(ark   
      
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