SB PROP @ ARL $ARLP023 ARLP023 Propagation de K7RA ZCZC AP23 QST de W1AW Propagation Forecast Bulletin 23 ARLP023 From Tad Cook, K7RA Seattle, WA June 4, 2021 To all radio amateurs SB PROP ARL ARLP023 ARLP023 Propagation de K7RA Solar Cycle 25 activity continues this week, with no spotless days since May 6. Average daily sunspot number rose modestly this week from 24.9 to 28, and average daily solar flux held steady at 77.8, unchanged from last week. Predicted solar flux over the next month is 75 on June 4-6, 72 on June 7-11, 78 on June 12-15, 80 on June 16-18, 78 on June 19-22, then 76, 75 and 76 on June 23-25, 72 on June 26 through July 5, then 73,75 and 76 on July 6-8. Solar flux may rise to 80 on July 13-15. Predicted planetary A index is 8 on June 4, 5 on June 5-15, 20 and 10 on June 16-17, 5 on June 18-27, then 8, 5, 8 and 8 on June 28 through July 1, and 5 on July 2-12. Geomagnetic activity forecast for the period June 4-29, 2021 from OK1HH. "Geomagnetic field will be: quiet on: June 10, 12-13, 24-27 quiet to unsettled on: June 5-6, 17-20, 28-29 quiet to active on: June 4, 7-9, 11, 14-15, 21-23 unsettled to active: June 16 active to disturbed: nothing predicted "Solar wind will intensify on: June (7,) 9, (14-19, 22, 24, 29). "The increased geomagnetic activity on May 26-27 was caused by solar flares with CME on May 22. Therefore, it could not be predicted in forecast issued on May 20. "Parenthesis means lower probability of activity enhancement. "Accuracy of the forecast remains lower." From Madison DX Club, program for Tuesday evening, June 8th. All are welcome. "'Modes of Propagation on 6 Meters' will be presented by propagation expert Carl Luetzelschwab, K9LA. Carl will begin with a brief look at the atmosphere and the ionosphere. He will then cover atmospheric modes (including polar mesosphere summer echoes and the Hepburn tropo maps) and ionospheric modes (E and F2 regions and sporadic-E). G3YLA's and K1YOW's recent work with sporadic-E, and the eBook by K5ND on 6m will be discussed. Finally, references for more 6m info will be listed. Carl will be available to answer your questions, so please join us for another interesting evening on Tuesday, June 8th. All are welcome. "Time: Our Zoom host and Program Chairman, Kevin Shea, N9JKP, will be online from 5:45 PM Central Daylight Time to socialize before the business meeting begins and to provide time to work through any technical issues. In case of problems getting on, you can call or text Kevin at (608) 444-4125. "A brief business meeting will begin at 6:00 PM Central Daylight Time. The program will begin immediately following the meeting at 6:30 PM Central Daylight Time, sharp. All interested hams are welcome. "To Join the Zoom Meeting and Program simply use this link: "https://us02web.zoom.us/j/83181396616?pwd=dUIrdWo3bE45T0xyUkZOS2xKdDBIZz09 "Meeting ID: 831 8139 6616 Password: 124658" Oleh, KD7WPJ/UR5BCP wrote: "In the latest Propagation report you published N4SO's statement that UX0ZAB is not a Ukraine call sign. "It is not true. "UX prefix belongs to Ukraine, and UX0ZAB is a Ukrainian call sign. "You will find additional information about UX0ZAB from QRZ.com." 10-meter activity is starting to pick up. Here is a web site promoting 10-meters: http://www.n6na.org/home/ten-meters Interesting article on solar cycle prediction: https://bit.ly/3cfSL2V Dr. Tamitha Skov, WX6SWW, reports the first radiation storm of Solar Cycle 25: https://youtu.be/AfMDbesGWjA If you would like to make a comment or have a tip for our readers, please email the author at, k7ra@arrl.net . For more information concerning shortwave radio propagation, see http://www.arrl.org/propagation and the ARRL Technical Information Service web page 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. 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 May 27 through June 2, 2021 were 34, 28, 26, 27, 31, 20, and 30, with a mean of 28. 10.7 cm flux was 83.3, 77.4, 76, 74.4, 81.7, 75.2, and 76.3, with a mean of 77.8. Estimated planetary A indices were 16, 3, 7, 6, 3, 3, and 5, with a mean of 6.1. Middle latitude A index was 15, 3, 7, 7, 4, 3, and 5, with a mean of 6.3. NNNN /EX