SB PROP @ ARL $ARLP052 ARLP052 Propagation de K7RA ZCZC AP52 QST de W1AW Propagation Forecast Bulletin 52 ARLP052 From Tad Cook, K7RA Seattle, WA December 30, 2022 To all radio amateurs SB PROP ARL ARLP052 ARLP052 Propagation de K7RA This reporting week (December 22-28) saw declining solar numbers and rising geomagnetic indicators. Average daily sunspot numbers dropped from 124.1 to 96.1, and solar flux from 153.8 to 143.8. Average planetary A index rose from 6.7 to 17.3, and middle latitude numbers from 5.1 to 12.6. Predicted solar flux is 164 and 162 on December 30-31, 160 January 1-3, 2023, 158 on January 4, 156 on January 5-6, 140 on January 7-8, 136 on January 9, 130 on January 10-14, then 128 and 125 on January 15-16, 120 on January 17-20, then 125, 135, 136, 138, 132, 134 and 132 on January 21-27, 130 on January 28-29, 135 on January 30, and 140 on January 31 through February 4. Predicted planetary A index is 16, 14, 10 and 8 on December 30, 2022 through January 2, 2023, 5 and 14 on January 3-4, then 18, 18 and 10 on January 5-7, 5 on January 8-16, then 8, 12, 25 and 20 on January 17-20, 10 on January 21-22, then 20, 15, 10, 15 and 12 on January 23-27, and 10, 5 and 18 on January 28-30, then then 10, 10, 8 and 10 on January 31 through February 3, and a nice quiet 5 beyond that, perhaps until mid-February. The observatory at Penticton, British Columbia is the source for our solar flux numbers, and the staff leaves annually from Christmas to New Years. The system is automated, and we get the daily noon readings from this source: https://bit.ly/3hWlhN1 Unfortunately, the system crashed on December 24 and no readings were posted after Christmas Eve. Thanks to Dr. Andrew Gray, Research Council Officer at the Dominion Radio Astrophysical Observatory for monitoring his email while on holiday and supplying us with the four days of missing data. From Thomas Bayer, RWC Prague at the Budkov Observatory: "Geomagnetic activity forecast for the period December 30 - January 05, 2023. "Quiet: Dec 30, Jan 2-3 Unsettled: Dec 30-31, Jan 3-5 Active: Dec 31-Jan 1, Jan 3-5 Minor storm: Jan 3-4 Major storm: 0 Severe storm: 0 "We expect a transitional geomagnetic activity decrease during the coming two days. Then, about New Year, we expect partial geomagnetic activity enhancement again with a possible active event. "The other active/minor storm event is expected about January 3 - 4 in connection with coronal hole 60/-3. "Between these events, we expect quiet to unsettled conditions generally." From F.K. Janda, OK1HH: "Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere December 30 - January 05, 2023. "A week ago it seemed that the relatively low solar activity would remain so until Christmas. All observable sunspot groups had relatively stable magnetic fields, not enough to generate major flares. At the same time, a series of geomagnetically disturbed days continued until 27 December, with highly variable and difficult-to-predict evolution of ionospheric shortwave propagation. Average days were irregularly interspersed with above-average ones. "From December 25, sunspot group AR3169 suddenly began to increase. Trailing behind it is AR3171, and both are now approaching the western edge of the solar disk. "The CME observed on Christmas Eve after a magnetic filament explosion, likely partially impacted Earth and contributed to the slow decline in solar wind speed during the third decade (ten day period) of December. "According to NOAA forecasts, there is a possibility of G1 class geomagnetic storms on December 30-31, when the Earth's magnetic field is likely to hit the Co-rotating Interaction Region (CIR). We expect increased geomagnetic activity and auroras at higher latitudes again. "Thanks to helioseismology, we know of three active regions on the far side of the Sun. They are large enough to last until their heliographic longitudes reach the eastern limb of the solar disk. Therefore, total solar activity should not drop much anytime soon." Another over-the-top article describing flares as existential threats. https://bit.ly/3Wy8BuZ Unusual solar events: https://bit.ly/3hTQiS0 Big 2022 solar news: https://www.livescience.com/solar-storm-stories-2022 A New Year's forecast from Dr. Tamitha Skov, WX6SWW, our Space Weather Woman: https://youtu.be/XYIxYsQ2SUk Don't forget, New Year's Eve (in North America) and New Year's Day is Straight Key Night: http://www.arrl.org/straight-key-night Send your tips, reports, observations, questions, and comments to k7ra@arrl.net. 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 . 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 December 22 through 28, 2022 were 108, 100, 85, 107, 96, 89, and 88, with a mean of 96.1. 10.7 cm flux was 131.3, 127.7, 133.3, 144, 150.5, 159, and 160.4, with a mean of 143.8. Estimated planetary A indices were 12, 24, 23, 10, 22, 25, and 5, with a mean of 17.3. Middle latitude A index was 7, 19, 15, 8, 19, 16, and 4, with a mean of 12.6. NNNN /EX