TZUTC: -0500   
   MSGID: 601.fidonet-ls_arrl@1:2320/33 29204777   
   PID: Synchronet 3.20a-Win32 master/777fb6d8b Jun 13 2023 MSC 1929   
   TID: SBBSecho 3.20-Win32 master/777fb6d8b Jun 13 2023 MSC 1929   
   BBSID: TBOLT   
   CHRS: ASCII 1   
      
   SB PROP @ ARL $ARLP029   
   ARLP029 Propagation de K7RA   
      
   ZCZC AP29   
   QST de W1AW    
   Propagation Forecast Bulletin 29  ARLP029   
   From Tad Cook, K7RA   
   Seattle, WA  July 21, 2023   
   To all radio amateurs   
      
   SB PROP ARL ARLP029   
   ARLP029 Propagation de K7RA   
      
   Average daily sunspot numbers declined, but average daily solar flux   
   increased.  Sunspot averages were 181.9 last week, and 130.6 this   
   week.  Average daily solar flux increased from 179.4 to 190.5.   
      
   Two new sunspot groups emerged on July 14, three more on July 17 and   
   another two on July 19.   
      
   Average daily planetary and middle latitude A index were both 12.9   
   this week, rising from 8.6 and 8.1.   
      
   Predicted solar flux is 185 on July 21-23, then 180, 178, 175 and   
   170 on July 24-27, 165 on July 28-29, 170 on July 30-31, 165 on   
   August 1-4, then 170, 175, 175 and 170 on August 5-8, 165 on August   
   9-11, 170 on August 12, 175 on August 13-14, and 170 on August   
   15-19, 160 on August 20-23, 165 on August 24-25, then 170 on August   
   26-27 and 165 on August 28-31.   
      
   Predicted planetary A index is 20, 12, 8, 12 and 10 on July 21-25, 5   
   on July 26 through August 2, then 10 and 8 on August 3-4, 5 on   
   August 5-14, then 12, 8 and 8 on August 15-17, and 5 on August   
   18-29.   
      
   Weekly Commentary on the Sun, the Magnetosphere, and the Earth's   
   Ionosphere for July 20, 2023 from OK1HH.   
      
   "We've seen another seven days of mostly moderate solar activity,   
   with almost daily eruptions of moderate magnitude on the Sun.  Some   
   of these have been the source of CMEs.  If the Earth has been   
   affected by them, a geomagnetic disturbance followed, with a drop in   
   MUF and a worsening of HF propagation in the process.   
      
   As predicted, the expected CME hit the Earth's magnetic field on the   
   afternoon of 14 July (as part of the Bastille Day celebrations, but   
   not nearly as strongly as in 2000).   
      
   Another CME left the Sun on 14 July, and yet another on July 15.   
   Because the cloud of later ejected solar plasma was faster, it   
   cannibalized the previous CME.  Together, they hit the Earth on July   
   18.   
      
   But by then AR3363 had already produced a significant long-lasting   
   M6-class solar flare, and energetic protons accelerated by this   
   flare reached the Earth and caused a radiation storm.  Although MUFs   
   were quite high, HF conditions were adversely affected by frequent   
   occurrences of attenuation.   
      
   Another CME hit the Earth on 20 July, registered by the Earth's   
   magnetic field at 1708 UTC.   
      
   Further developments were predicted up to G1 to G2 class geomagnetic   
   storms, with a small probability also of G3, but by then this report   
   will have been completed and sent out.   
      
   Finally, just a little note on the consequences of global change: it   
   has been manifested in the last eleven-year cycles, in the Earth's   
   troposphere it is the result of warming, but in the ionosphere it is   
   rather the opposite.  It has been the subject of a number of   
   scientific papers in recent years.   
      
   It is crucial for us, for amateur radio practice, that the current   
   MUFs are lower than those calculated from sunspot counts for most of   
   the twentieth century.  Therefore, we should input Ri (or solar flux   
   SFU) into forecast programs lower than what is currently measured   
   and published.   
      
   F.K. Janda, A.R.S. OK1HH http://ok1hh.nagano.cz/ "   
      
   News from N8II in West Virginia.   
      
   "The bands are in much better shape than most hams realize; activity   
   levels are normally quite low this summer.  In the IARU contest I   
   observed 15M open to Europe through 0300 UTC and I had QSOs with   
   Indonesia, China, Nepal, Japan, Central/Western Siberia, Kazakhstan,   
   and the Philippines in the 2300-0300 UTC period.   
      
   I copied GR2HQ (Great Britain HQ station) on 10M CW at 0140 UTC.  At   
   1100 UTC on 15M EU and Central/West Asia were very loud and I   
   started running a pile up on CW.   
      
   The Far East was also in on 15M around 1400 UTC Saturday when I   
   worked a loud Japanese station.   
      
   During the evening/night EU signals were extremely loud on 20M.  I   
   also worked a few EU on 10M 1300-1400 UTC Saturday thanks to   
   Sporadic E and also caught Z30HQ (Macedonia HQ) on 10M CW Sunday   
   about 1130 UTC.  I worked 697 QSOs concentrating on DX on the high   
   bands in less than 12 hours with 100 W.   
      
   Africa is workable on 10-15M well into our evening as are South   
   Pacific stations.   
      
   Sporadic E this year seems somewhat attenuated, but Es was good from   
   here and great from the Central/Western USA during the June VHF   
   contest.  I made about 170 CW/SSB QSOs."   
      
   CNN presented a smart piece on the sunspot cycle peaking sooner than   
   expected.  https://bit.ly/3rzNJJ6   
      
   Double peaked flare.  https://bit.ly/46ZoznE   
      
   Astronomy club observes sunspots.  https://bit.ly/46SaacR   
      
   Aurora.  https://bit.ly/44FxM2U   
      
   Scientific American.  https://bit.ly/3rHzGkB   
      
   Early peak.  https://bit.ly/44Aa7AF  https://bit.ly/3rEa0Wj   
      
   Cannibal eruption.  https://bit.ly/3Q5dv1W   
      
   Great video of eruption.  https://youtu.be/YOzHHM4B4gA   
      
   The latest from Space Weather Woman Dr. Tamitha Skov, WX6SWW.   
      
   https://youtu.be/KsKDVOuboyw   
      
   Send your tips, reports, observations, questions and comments to   
   k7ra@arrl.net.  When reporting observations, don't forget to tell   
   us which mode you were operating.   
      
   For more information concerning shortwave radio propagation, see   
   http://www.arrl.org/propagation and 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 .   
      
   Also, check this article from September, 2002 QST:   
      
   https://www.arrl.org/files/file/Technology/tis/info/pdf/0209038.pdf   
      
   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/   
      
   Instructions for starting or ending email distribution of ARRL   
   bulletins are at http://arrl.org/bulletins   
      
   Sunspot numbers for July 13 through 19, 2023 were 146, 141, 96, 99,   
   149, 142, and 141, with a mean of 130.6.  10.7 cm flux was 202.9,   
   180.6, 178.5, 184.3, 180, 218.5, and 188.9, with a mean of 190.5.   
   Estimated planetary A indices were 7, 20, 8, 10, 24, 16, and 5, with   
   a mean of 12.9.  Middle latitude A index was 9, 17, 9, 13, 19, 16,   
   and 7, with a mean of 12.9.   
   NNNN   
   /EX   
   --- SBBSecho 3.20-Win32   
    * Origin: The Thunderbolt BBS - Little Rock, Arkansas (1:2320/33)   
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