SB PROP @ ARL $ARLP027 ARLP027 Propagation de K7RA ZCZC AP27 QST de W1AW Propagation Forecast Bulletin 27 ARLP027 From Tad Cook, K7RA Seattle, WA July 6, 2018 To all radio amateurs SB PROP ARL ARLP027 ARLP027 Propagation de K7RA No sunspots have appeared since June 26. If we use predicted solar flux as a proxy, flux is expected to be less than 70 until July 8, this Sunday, so I would not expect sunspot activity to resume perhaps until July 13 to 23 when solar flux is expected to rise above 70. Predicted solar flux is 68 on July 6 and 7, 70 on July 8 to 12, 72 on July 13, 75 on July 14 and 15, 77 on July 16, 80 on July 17 to 19, 77 on July 20 and 21, 73 and 71 on July 22 and 23, 70 on July 24 and 25, 69 on July 26 and 27, 68 on July 28 to August 5, 69 on August 6, 72 on August 7 to 9, 75 on August 10 and 11, 77 on August 12, 80 on August 13 to 15, 77 on August 16 and 17, then 73 and 71 on August 18 and 19. Predicted planetary A index is 10 on July 6, 5 on July 7 to 14, then 15 on July 15, 5 on July 16 to 19, then 15, 8, 10, 18 and 7 on July 20 to 24, 5 on July 25 to 28, 8 on July 29, 5 on July 30 through August 10, 15 on August 11, 5 on August 12 to 15, then 15, 8, 10 and 18 on August 16 to 19. Chip Margelli, K7JA had a comment on the coverage of Field Day conditions last week: "Hi Tad. Saw your propagation report re Field Day. Still trying to figure out which planet that represented. Conditions on FD were generally awful. The K index rising to 4 Saturday morning really tore up the bands, and blew out the E layer out west. Neither six nor 10 opened up at all on Saturday, and there were only a few pop-up paths that emerged on Sunday on ten. On six, while much of the eastern part of the country had a big band, in southern California we worked five whole stations in South Dakota. That was it. Twenty was "fair," but it closed early Saturday night. Fifteen was a huge bust, and 40 was very disturbed, with heavy QSB and east coast signals generally huddling right at the edge of being audible. Forty never really took off to the east, causing us to be at least 30% off of our anticipated numbers. Not a good weekend for prop at all. And very disappointing, because six had been wide open all week before FD, and here a week after FD it is again open across the country. Just not the Saturday and Sunday of FD. Sigh. 73 de Chip K7JA" For more information concerning radio propagation, see 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. 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 June 28 to July 4, 2018 were 0, 0, 0, 0, 0, 0, and 0, with a mean of 0. 10.7 cm flux was 69.5, 68.6, 68.8, 68.1, 66.6, 68.2, and 67.9, with a mean of 68.2. Estimated planetary A indices were 5, 4, 4, 3, 3, 4, and 5, with a mean of 4. Estimated mid-latitude A indices were 5, 3, 3, 4, 4, 5, and 4, with a mean of 4. NNNN /EX