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The K7RA Solar Update

05/31/2019

No sunspots appeared over this past reporting week, May 23-29.

Compared to the previous seven days, average daily solar flux dropped from 69.8 to 67.4. Average daily planetary A index increased from 5 to 7.3, and average mid-latitude A index went from 6.1 to 8.1.

Predicted solar flux over the next 45 days is 70 on May 31, 71 on June 1, 72 on June 2-6, 76 on June 7-10, 74 on June 11, 72 on June 12-13, 70 on June 14-15, 69 on June 16-17, 68 on June 18, 67 on June 19-26, 68 and 70 on June 27-28, 72 on June 29 through July 10, then 70 and 68 on July 11-12 and 67 on July 13-14.

Predicted planetary A index is 8 on May 31, 5 on June 1-4, 8 on June 5-6, 5 on June 7-15, 8 on June 16-18, 5 on June 19-23, then 10, 16, 12, 10, 10 and 8 on June 24-29 and 5 on June 30 through July 14.

When might we see a return of visible sunspots? Perhaps a table of recent sunspot numbers and solar flux gives us a clue: ftp://ftp.swpc.noaa.gov/pub/indices/old_indices/2019Q2_DSD.txt

Note when the solar flux dropped below 70, sunspots disappeared. With predicted flux values above 70 for the first half of June, perhaps we won’t have long to wait.

OK1HH sends us his geomagnetic forecast.

Geomagnetic activity forecast for the period May 31 thru June 26, 2019.

Geomagnetic field will be:
Quiet on June 13-14
Quiet to unsettled on May 31, June 1-6, 9, 15, 19-22
Quiet to active on June 8, 11-12, 16-18
Unsettled to active on June 7, 10, 23-26

Solar wind will intensify on (May 31-June 1,) June 10-14, 24-26

Parenthesis means lower probability of activity enhancement.

N8II sent us his observations on last weekend’s CQ WW WPX CW contest, from West Virginia: "Band conditions during the 2 weeks leading up to the WPX CW contest were quite poor from here except for a few sporadic E openings including one on 10-meter phone via double hop to Oregon and Washington.

“Right from the start of the contest, however, conditions were exceptional. In the first few minutes I worked New Zealand and Hawaii on 15 meters, both weak. Twenty meters was wide open to almost all of Europe excluding Britain and France/Benelux countries until about 0115Z, then still open well to some of Europe. Asia conditions improved then including some Russians in zone 18 and Kazakhstan. There was some short skip into the USA and Canada indicating some sporadic E help. N3QE in Maryland nearby reported best ever WPX CW 80-meter conditions and 40 meters was excellent as well Friday night.

“Saturday morning the sporadic E fun continued. I also logged two big-gun Japanese stations around 1240Z. Over the weekend, I made 204 contacts on 15 meters. About 65% were in the USA and Canada, and then I went on to make 45 contacts on 10 meters. The first European to go into the 15-meter log was SP8R in Poland at 1256Z, followed quickly by UW3U in Ukraine. There were very few loud European signals on 15 meters on Saturday, but many that I struggled to work then were much louder on Sunday. Saturday conditions favored Central Europe with Hungary, Czech and Slovak Republics, Slovenia, Croatia and Italy going into the log.

“Amazingly, I was able to technically work all continents over the two days on both 15 and 10 meters thanks to the multi-hop sporadic E! P33W in Cyprus was logged on 40-10 meters for Asia; CN3A, Morocco (also 40 through 10 meters); CR3DX, Madeira Island for Africa; WH7V on 10 meters (1853Z Saturday; very rare); several Hawaiians on 15 meters for Oceania; YW1K, Venezuela (my only South American on 10 meters); YT7Z in Serbia at 1442Z Sunday on 10 meters along with HG3N in Hungary; LZ8R in Bulgaria; IB9T in Sicily, and CR6K in Portugal – all for Europe, of course.

“Each late afternoon Europe boomed in on 20 meters until past 2400Z (Friday/Saturday). At the end of the contest there was good sporadic E in almost every direction. On both Saturday and Sunday evenings there was essentially no skip zone on 40 meters versus the usual one extending into New York, New England, Ohio and North Carolina. Europe was exceptional on 40 meters from 2400Z-0200Z Saturday evening with low static crashes."

When Jeff mentioned ”Benelux,” I had to look this up, and no, it wasn’t a typo. In fact, it has been around since 1944: https://en.wikipedia.org/wiki/Benelux. Until I read this, I also had no idea that “Luxembourgish” is a language.

On May 25, Ken Brown, N4SO, of Alabama sent this report on recent 40-meter FT8 activity: "I was running FT8 at just 10 W output to a half-square antenna. I managed to work YB3BBF in Indonesia at 2343 UTC, which is unusual, especially with the Caribbean, South America, and Europe coming through all at the same time. Other call signs copied include 9K2NO, ON4XM, EW8W, JA1EOD, JK7CWL, YC8MJG, 4E1FNS and DS5USH.”


Here is the best article I’ve ever read describing the solar cycle prediction panel that met in Boulder in the first week in March, and “best” includes any of the previous meetings: https://bit.ly/2HMh21S. The writer makes a common error in confusing the daily sunspot number with the number of sunspots, no doubt due to the arcane method for arriving at the number. She mentions 14 sunspots, but the sunspot number on the day of the meeting was 14, meaning there were four sunspots within a single group. The sunspot number counts 10 points for each group, and one point each for the sunspots within that group.

Thanks to Paul Drahn, KD7HB for this: https://phys.org/news/2019-05-corroborates-planetary-tidal-solar.html

If you would like to make a comment or have a tip for our readers, email the author at k7ra@arrl.net.

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 May 23 through 29, 2019 were 0, 0, 0, 0, 0, 0, and 0, with a mean of 0. 10.7 cm flux was 66.5, 66.4, 67, 68, 67.5, 68.1, and 68.2, with a mean of 67.4. Estimated planetary A indices were 5, 5, 4, 5, 10, 8, and 14, with a mean of 7.3. Middle latitude A index was 5, 6, 3, 6, 12, 9, and 16, with a mean of 8.1.

 



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