Subj : The K7RA Solar Update To : QST From : ARRL de WD1CKS Date : Mon Oct 14 2024 17:48:12 10/04/2024 ASWFC GEOMAGNETIC DISTURBANCE WARNING ISSUED AT 0042UT/04 OCTOBER 2024 BY THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE. Two coronal mass ejections first observed on 01-Oct and 03-Oct are expected to impact Earth over 04-05 Oct. Lack of analyzable corona graph imagery makes arrival time predictions uncertain. INCREASED GEOMAGNETIC ACTIVITY EXPECTED DUE TO CORONAL MASS EJECTION FROM 04-06 OCTOBER 2024. GEOMAGNETIC ACTIVITY FORECAST: 04 Oct:ÿ G3, chance of G4 05 Oct:ÿ G3, chance of G4 06 Oct:ÿ G1-G2 New sunspot groups emerged on every day over the past week. Two new regions appeared on September 26, another on September 27, two more on September 28, another on September 29, another on September 30, three more on October 1 and another on October 2, for a total of eleven. Average daily sunspot number rose from 137.1 to 164.7, and average daily solar flux from 164.3 to 213.1. Average daily planetary A index shifted from 14.3 to 9.6. Predicted solar flux is 310 on October 4-6, 300 on October 7, 290 on October 8-10, 175 on October 11-16, 170 on October 17-21, then 175, 180, 185, 190 and 195 on October 22-26, then 200 on October 27-29, 205 on October 30 through November 4, then 200 and 185 on November 5-6 and 175 on November 7-12. Predicted planetary A index is 54, 94, 72, 22 and 15 on October 4-8, 5 on October 9-10, then 20 and 19 on October 11-12, then 5 on October 13-21, then 28 and 10 on October 22-23, 5 on October 24-26, and 10 on October 27, then 5 on October 28-31, 10 on November 1-2, 5 on November 3-5, then 10, 20, and 19 on November 6-8, and 5 on November 9 and the foreseeable future. Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere - October 3, 2024 from OK1HH: "After AR3811 disappeared from our field of view behind the southwestern limb of the solar disk on September 12, it was continuously tracked by helioseismological methods until September 29, when it reappeared in the southeast, numbered AR3842. Its size and activity on the far side of the Sun suggested that we could look forward to a lot of activity in October. "And so, it did. When solar flare X7.1/2b was observed on October 1 with a maximum at 2220 UT, the second largest in the current 11-year cycle, I planned to start with this announcement. But when flare X9.05, newly the largest in X-ray intensity in the same AR3842, was observed on October 3 at 1218 UT, that was no longer the case. "The source region of AR3842 was heading straight towards us. So, the plasma cloud was probably heading directly for our ionosphere. Unlike the aforementioned X7.1/2b (which thus moved to the third largest), it is very likely that the CME of October 3 will hit Earth. We therefore expect a disrupted end of the week. "This weekend we can expect low MUF and high LUF on shortwave and QSOs over aurora on VHF. Early next week will see a gradual return to average and then above average radio wave propagation conditions in the ionosphere." From "The New Zealand Herald," Aurora in Auckland: https://bit.ly/3NcNOde[1] Radio Blackout hits U.S.: https://bit.ly/3zNlkno[2] https://www.space.com/sun-monster-solar-flare-x7-video[3] Here is the latest update from Dr. Tamitha Skov, WX6SWW: https://youtu.be/QDf6eyTCbe4[4] Send your tips, reports, observations, questions and comments to k7ra@arrl.net[5]. 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[6] and the ARRL Technical Information Service web page at, http://arrl.org/propagation-of-rf-signals[7]. For an explanation of numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere[8] . An archive of past propagation bulletins is at http://arrl.org/w1aw-bulletins-archive-propagation[9] . More good information and tutorials on propagation are at http://k9la.us/[10] . Also, check this article: https://bit.ly/3Rc8Njt [11] "Understanding Solar Indices" from September 2002 QST. Instructions for starting or ending email subscriptions to ARRL bulletins are at http://arrl.org/bulletins[12] . Sunspot numbers for September 26 through October 2 2024 were 189, 122, 148, 154, 150, 196, and 194, with a mean of 164.7. 10.7 cm flux was 181.1, 186, 194.5, 197.2, 214.2, 244.6, and 274.4, with a mean of 213.1. Estimated planetary A indices were 13, 7, 7, 16, 11, 6, and 7, with a mean of 9.6. Middle latitude A Index was 11, 5, 5, 17, 5, 9, and 6, with a mean of 8.3. ÿ [1] https://bit.ly/3NcNOde [2] https://bit.ly/3zNlkno [3] https://www.space.com/sun-monster-solar-flare-x7-video [4] https://youtu.be/QDf6eyTCbe4 [5] mailto:k7ra@arrl.net [6] http://www.arrl.org/propagation [7] http://arrl.org/propagation-of-rf-signals [8] http://arrl.org/the-sun-the-earth-the-ionosphere [9] http://arrl.org/w1aw-bulletins-archive-propagation [10] http://k9la.us/ [11] https://bit.ly/3Rc8Njt [12] http://arrl.org/bulletins --- þ Synchronet þ Whiskey Lover's Amateur Radio BBS .