During our reporting week (March 21-27) solar activity increased while geomagnetic indicators were lower, compared to the previous seven days. This is a nice combination for the first week of spring.
Although sunspots and solar flux decreased toward the end of the period, average daily sunspot numbers doubled from 8 to 16, and average daily solar flux increased from 70.7 to 75.2.
Average daily planetary A index decreased from 8.1 to 3.7, and average daily middle latitude A index decreased from 6.3 to 3.9.
These numbers are all good, because higher sunspot numbers and solar flux suggest better enhancement of the ionosphere while the lower geomagnetic numbers correspond to generally lower absorption or disturbed conditions.
The planetary A index is a composite from magnetometers around the globe, but the middle latitude A index is from a single magnetometer in Virginia.
Predicted solar flux from the March 28 forecast is 68 on March 29 through April 4, 70 on April 5-6, then 71 and 74 on April 7-8, 75 on April 9-18, then 74, 73, 73 and 71 on April 19-22, 70 on April 23 through May 3, 71 and 74 on May 4-5, and 75 on May 6-12.
Predicted planetary A index is 12 on March 29, 8 on March 30 through April 2, 6 and 8 on April 3-4, 5 on April 5-11, then 15 and 10 on April 12-13, 5 on April 14-21, then 8, 12, 12, 8 and 8 on April 22-26, 5 on April 27-28, 8 on April 29-30, 5 on May 1-8, then 12, 8, 5 and 5 on May 9-12.
The above predictions for solar flux and A index are updated daily at ftp://ftp.swpc.noaa.gov/pub/forecasts/45DF/ .
There have been no sunspots on March 26-28. Here is an image of sunspot group AR2736 from March 23, a few days before it disappeared: https://bit.ly/2utHqGj
From F.K. Janda, OK1HH:
Geomagnetic activity forecast for the period March 29 until April 27, 2019
Geomagnetic field will be:
Quiet on March 31, April 11, 16, 18-21, 27
Quiet to unsettled on March April 1-4, 11-12, 22, 25-26
Quiet to active on March 30, April 6-10, 15, 23-24
Unsettled to active on March 29, April 5, 13-14, 17
Solar wind will intensify on March 29 (- 30), April (2-6,) 12-13, 15-16. Parenthesis means lower probability of activity enhancement.
NN4X sent this report: “On March 26 I tried 17 meters and worked into Australia and New Zealand on a seemingly dead band. I worked E6 on 3/27 at 21:41Z. Additional countries worked included Spain, France, St Helena, and Yugoslavia. I had to leave after 5:00 PM local so was not able to look west for any late afternoon/early evening openings, although I don’t see anything posted to DX Cluster.
“On March 28 I decided to call CQ into a ‘dead’ 12-meter band, and soon saw PSKReporter.info showing I was heard in Spain. I continued calling and soon made contacts with Spain, Brazil, Puerto Rico, and Argentina. I was also heard in France.
“Once again, it pays to make some noise; you never know who’s listening, or where.”
The CQ World Wide WPX SSB Contest is this weekend. See https://www.cqwpx.com/
The latest from Dr. Tamitha Skov, WX6SWW: “What happened nationwide this past week [the media hyping of a ‘solar storm’] was a tragedy– it did not need to happen. It’s always personally painful to me when some members of the media jump on these storms and hype them beyond recognition. Seduced by the allure of aurora views and a world of science-fiction adventure, people from all over then embark on a solar storm crusade. They pack their bags, and their cars, and head hundreds of miles towards the poles singing victory songs with stars in their eyes. Their trip begins with enthusiasm, awe, and wonder, but it ends tragically. It leaves many feeling confused and left out in the dark and cold (literally) as they look skyward for an aurora show that never comes.
“Events like these are stark reminders of why it’s so critical we continue to push forward to create a field of Space Weather broadcasting. When the media runs amok, omitting critical aspects of Space Weather that make forecasting so difficult and aurora so elusive, it traps everyone in its web. You, me, and especially the uninitiated. But there is a bright spark I am beginning to see. Far more than ever before, I saw this community push back on the hype. What is more– I watched as journalists and meteorologists alike, learned from us. As in the picture above, I saw proof we are winning the battle. We are slowly pushing back against the media veil that continues to keep Space Weather shrouded in mystery. I know a huge part of our success is due to you, and I am eternally grateful.
“As for this week’s forecast, our Sun calms down a bit as rogue region 2736 rotates to the Sun’s backside. We won’t see it again for another two weeks. This means emergency, shortwave, and amateur radio propagation tanks again on Earth’s day side, even as GPS reception improves. We also get another chance for a solar storm from a small pocket of fast wind that is already brightening the aurora again. So at least that is good news for aurora hopefuls, who missed out on the show this past week. Too bad no media are reporting on the aurora viewing chances now. They’re better than during the peak of the hype. So much for a fizzle and a frenzy.”
See Dr. Skov’s latest video here: https://youtu.be/I4TiyYm1u4s
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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/.
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 March 21 through 27, 2019 were 49, 27, 22, 14, 0, 0, and 0, with a mean of 16. 10.7 cm flux was 80.1, 82.4, 79.4, 75.4, 71.2, 69, and 68.9, with a mean of 75.2. Estimated planetary A indices were 2, 1, 1, 3, 5, 6, and 8, with a mean of 3.7. Middle latitude A index was 2, 2, 2, 3, 5, 5, and 8, with a mean of 3.9