SB PROP @ ARL $ARLP034 ARLP034 Propagation de K9LA ZCZC AP34 QST de W1AW Propagation Forecast Bulletin 34 ARLP034 From Carl Luetzelschwab, K9LA Fort Wayne, IN August 12, 2005 To all radio amateurs SB PROP ARL ARLP034 ARLP034 Propagation de K9LA Carl Luetzelschwab, K9LA, is filling in for Tad Cook, K7RA, this week. This report covers the period Friday, August 5 through Thursday, August 11, with a 3-day outlook for August 12-14. Solar activity was low to very low during the reporting period, with the biggest flare being a C2.8 on the first day. Geophysical activity ranged from quiet (Friday, Monday, Tuesday, and Thursday) to minor storm (Saturday, Sunday, and Wednesday). Very low solar activity and quiet to unsettled geophysical activity are predicted for the next three days. There have been several 50 MHz spots on PacketCluster during this reporting period. These spots reminded this reporter of an old plot of sporadic E probability versus month and time of day. The web version of this bulletin includes this plot. Although the data is from 1957 and 1958, it should still offer a good guideline for the probability of sporadic E occurrences. This plot comes from one of the old geophysics handbooks published by the USAF. Note that we are moving away from the high probability months for sporadic E. Some of the more interesting DX scheduled to be on this weekend includes PY0F, TK, 5X, HB0, P5, HS, and TY. Thanks to The Daily DX and QRZ DX. The best bands for working these stations should be 40, 30, 20, and 17 meters. Use your favorite propagation prediction software to determine the best times of day. Operating events this weekend include the WAE (Worked All Europe) DX contest (CW) and the Maryland-DC QSO party. It is likely that 20 and 40 meters, and to some extent 80 meters for the Maryland-DC QSO Party, will be the workhorse bands for these two events. For more information concerning radio propagation and an explanation of the numbers used in this bulletin see the ARRL Technical Information Service propagation page at, http://www.arrl.org/tis/info/propagation.html. An archive of past bulletins is found at, http://www.arrl.org/w1aw/prop/. Sunspot numbers for August 4 through 10 were 85, 74, 54, 67, 56, 51 and 34 with a mean of 60.1. 10.7 cm flux was 106.1, 98.8, 93.4, 92.3, 86.4, 82.5 and 76.3, with a mean of 90.8. Estimated planetary A indices were 14, 9, 34, 18, 8, 10 and 22 with a mean of 16.4. Estimated mid-latitude A indices were 9, 6, 25, 12, 6, 8 and 9, with a mean of 10.7. NNNN /EX