Similar to the last reporting week in ARLP014, the first three days (Thursday through Saturday) had no visible sunspots, but sunspots returned on Sunday through Thursday. Average daily sunspot number declined from 9.4 to 6.9, but average daily solar flux rose from 69.5 to 75.4.
Geomagnetic indicators were slightly more active, with average daily planetary A index increasing from 8.4 to 10.6, and average middle latitude A index from 7.3 to 9.
Predicted solar flux for the next 45 days is 78 on April 12-17, 76 and 74 on April 18-19, 70 on April 20-22, 69 on April 23, 70 on April 24-28, 71 on April 29 through May 1, 72 on May 2-3, 77 on May 4-6, 74 on May 7-16, 70 on May 17-19, then 69, 68, 69 and 69 on May 20-23, 70 on May 24-25 and 71 on May 26.
Predicted planetary A index is 12 on April 12-13, 5 on April 14-23, then 10, 8, 5, 10, 8, and 5 on April 24-29, 10 on April 30 through May 2, 7 on May 3, 5 on May 4-20, then 10, 8, 5, 10, 8 and 5 on May 21-26.
On April 7 sunspot group 2738 appeared. Currently (Thursday, April 11) you can see it as the bright spot on the STEREO image at: https://stereo.gsfc.nasa.gov/Of course, the bright spot will move from left to right over time, until it disappears off the right side.
Geomagnetic activity forecast for the period April 12 until May 8, 2019 from F.K. Janda, OK1HH.
Geomagnetic field will be:
Quiet on April 14, 17-19
Quiet to unsettled on April 16, 20-23, 26, 29, May 2-4
Quiet to active on April (15,) 28, May 1
Unsettled to active on April (24-25, 27,) 30, May 5-8
Active to disturbed April (12-13)
Solar wind will intensify on April 12-13, 15-16, (19-23,) 24-25, (26-30,) May (1,) 2-3, (5, 8)
Parenthesis means lower probability of activity enhancement.
Thanks to David Moore for this article: https://www.sciencedaily.com/releases/2019/04/190404114437.htm
The Cycle 25 prediction panel met last week in Boulder, and they see an end to declining solar cycles, and they do not predict another grand minimum similar to the terrifying (to hams) Maunder Minimum. The Washington Post had an interesting take on the prediction, indicating the next cycle could be stronger: https://wapo.st/2IrROGx
Here is a tweet from Scott McIntosh, Director of the National Center for Atmospheric Research’s High-Altitude Observatory offering his opinion that Cycle 25 will be stronger than Cycle 24. https://twitter.com/swmcintosh/status/1116427188612497408
Steve Ford, WB8IMY, sent this article on accurate predictions of space weather. It has a nice video on the perils of space weather: https://phys.org/news/2019-04-accurately-space-weather.html
Mike Schaffer, KA3JAW, of Easton, Pennsylvania sent this report: “Tuesday evening, April 9, 2135 UTC (5:35 PM EDT local) I was monitoring the 11-meter Citizen Band (27 MHz) and telltale signs of Sporadic-E, swooshing, fading in and out of signals on channel 19, which is active with interstate truckers was causing interference to local operators. Sporadic-e was emerging from the state of Florida, around Miami.
“During the 2200 UTC (6:00 PM EDT local) central cities of Melbourne, Orlando, Ocala, and Gainesville were heard. At 2310 UTC (7:10 PM EDT local) the Es plasma cloud was shifting westerly over Tampa. Ten minutes later, Es had vanished. Most likely the cloud (not the internet one) had moved over the Gulf of Mexico where there are no truckers.
“The most distant station, Miami was 1,070 air miles from Easton, Pennsylvania. The MUF made it up into the 6-meter band, but not high enough for the low-VHF TV or the FM broadcast bands. The reported geomagnetic field was at quiet to unsettled levels with a 10.7cm flux at 79. The MUF had intensified with durations becoming longer compared to last week.”
Jeff, N8II, in West Virginia sent this report: “Here we go again; the SFI has been near 80 for 3-4 days, unexpectedly. Unfortunately, 15 meters has not come to life except for stations to the south. I keep seeing spots for C5DL in the Gambia on 15 meters and hear little or no signal. Seventeen meters does come to life a bit when the flux hits the upper 70s.
“Conditions were not good to Missouri during their QSO Party from here. Twenty meters was marginal, and then closed at around 1900Z Saturday and signals seemed weaker than expected on 40 during the day. On top of that, storms in the Gulf Coast area caused noise even on 20 meters and I was unable to work any Mississippi QSO Party stations on 75-meter phone during their round table net due to high noise on their end.
“The good news is that conditions on 30 meters down to 80 meters have been pretty good many nights. I would say the average signal levels on 80 far exceed the levels on December and January with March probably being the best month, but signals from the big guns in Europe are still S9+.
“I managed to work C5DL on 160 meters on the April 11 at 0044Z; they were Q5 copy about 90% of the time here with low noise levels. They have also been logged on 80, 40, 30, and 20 meters, but no luck on 17 meters so far.
“Most days, several European Russians are loud on 20 meters and they have several special prefixes running as well as many AM70 and other AM prefixes from Spain to celebrate the 80th anniversary of the URE.
“On April 11, signals were booming from Spain at 2100-2200Z on 20 meters; signals have been weak around 1300-1600Z from Spain, but I suspect most AM70 stations were beaming towards Eastern Europe.
On April 5, Turkey and two booming Bulgarians were worked on 20 meters in the 2000Z hour.
Mikhail, VE7ACN, has been touring islands in Nova Scotia and New Brunswick and generating large European pile ups on 40, 20, and even 17 meters. The skip zones are so long, that he skipped over me on 20 meters for several days until the solar flux improved. I can hear Southeast Asian stations some days on 20 but working through the European pile ups is very difficult.
“There is still a decent long path opening to Australia on 30 and 20 meters around 2100Z. That path was very good during our winter.
“Today, April 11, was fun with some booming signals from the south on 12 and 10 meters. I logged two stations from Columbia, two from Chile, and I worked St. Lucia on 10-meter SSB around at 2050Z. Teddy, VP2ETE, on Anguilla was loud on 12-meter SSB at 2115Z. Several of these stations were S9 or better here and they were only using dipoles.”
Dr. Skov, WX6SWW, issued this video report on April 10: https://youtu.be/m5E7aFZeE70
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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/.
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Sunspot numbers for April 4 through 10, 2019 were 0, 0, 0, 11, 12, 12, and 13, with a mean of 6.9. 10.7 cm flux was 70.3, 71.7, 73.6, 76.5, 78.6, 79, and 78.1, with a mean of 75.4. Estimated planetary A indices were 10, 14, 7, 5, 13, 11, and 14, with a mean of 10.6. Middle latitude A index was 8, 10, 7, 5, 12, 11, and 10, with a mean of 9.
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