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The K7RA Solar Update


Conditions over Field Day weekend turned out to be not bad at all. The expected geomagnetic upset never happened. On June 25-26, the Thursday and Friday before Field Day, the predicted planetary A index for the June 27-28 was 45 and 60, really bad conditions. The actual planetary A index on those dates was 9 and 13, and the mid-latitude A index was 8 and 12, nice moderate numbers.

Average solar flux over June 25 through July 1 was 100.7, down from 130.8 over the previous seven days. Average daily sunspot numbers declined from 71.6 to 35.9.

There were no new sunspots on June 17-21, one new spot on June 22, none on June 23-27, two new sunspots on June 28, a new sunspot on June 29 and again on June 30, and two new sunspots on July 2. On July 1 there were 3 numbered sunspot groups and 5 on July 2. NOAA/USAF predicts geomagnetic activity at quiet levels on July 3, quiet to unsettled July 4 and unsettled to minor storm levels on July 5.

The latest solar flux prediction has 115 on July 3-5, 120 on July 6-9, 125 on July 10, 130 on July 11-19, then 115, 110 and 105 on July 20-22, 100 on July 23-26, 105 on July 27 through August 1, then flux values rise to 130 after August 6.

Planetary A index is predicted at 5, 8, 25, 15, and 8 on July 3-7, then 5 on July 8-10, then 18, 12 and 8 on July 11-13, then 5 on July 14-17, 8 on July 18-19, 5 on July 20-25, 8 on July 26, 5 on July 27 through August 1, then 18, 15 and 12 on August 2-4 and 8 on August 5-6.

Franz Janda, OK1HH, predicts the geomagnetic field will be quiet to unsettled July 3-4, active to disturbed July 5, quiet to active July 6, quiet to unsettled July 7, mostly quiet July 8-10, quiet to active July 11-12, quiet to unsettled July 13-14, quiet on July 15, mostly quiet July 16-17, quiet to unsettled July 18, quiet to active July 19, quiet to unsettled July 20-21, quiet July 22-23, and mostly quiet July 24-25. Franz expects increases in solar wind on July 5-6, July 10-12 and July 20-25.

Dave Olean, K1WHS, of Lebanon, Maine wrote “I missed the big aurora in the early evening on Monday night June 23rd. I knew it was happening, but had company and could not break away. I finally did get away just about 0100 UT and there was six meter Es and shortly afterwards, I started hearing auroral buzz on several stations.”

Later he wrote, “I worked all sorts of 50 MHz aurora out into the far Midwest on June 22-23 aurora. In between the auroral buzz, I could also work several stations via 50 MHz auroral E out to the Seattle area with K7EK in CM97.

“I also worked VE5UF and VE6EME via auroral Es. It was interesting to look at the signals on my panadaptor. You could pick out the auroral Es signals from the plain auroral signals by their width on the screen! Later on, around 0500z, I tried really hard to work two KL7s, but alas, they could not hear me. I definitely heard them very weakly and with an auroral Es note, but I guess the path geometry was less than optimum. They could not pull me out. The W7 and VE auroral Es was 5x9!

“One interesting contact on 50 MHz was an auroral sounding QSO with N5DG near Houston, Texas. I have never worked that far via the buzz route. Ed, N5DG, said he also copied me with a raspy auroral note as well. Just before midnight, signals started to appear on 144 MHz. I had missed the earlier session, so was anxious to see if the aurora would come back later. It did, and I worked a few stations on 144 MHz for about half an hour. I had to retrain myself in auroral techniques as it has been a long time for me since there was a good aurora on 144. My quad Yagi array was too sharp, and I was constantly turning the beam to peak signals.

“I worked N4QWZ in Tennessee with 59+ signals. He was barely audible when I first heard him with my beam at 320 degrees. K1HTV in FM18 was worked early on with weak signals too at 0355Z, but later I peaked him up to 59+ by turning the beam more to the west. Some of my beam headings were as far south as 285 degrees! That is almost due west! I also worked several stations out in the Chicago area and Wisconsin, but I am afraid that the activity level was low due to it being a late week night. Chicago peaked at 308 degrees.

“After 144 MHz died around 0430, I went back to 50 MHz looking for more Auroral Es. The KL7s were heard after 0500Z. I hung around until 0700 looking for more DX to KL7, but nothing materialized.”

Check out the pictures on Dave’s listing at, especially his stack of antennas.

Rich Zwirko, of Amissville, Virginia (who K1WHS mentioned) reports: “June 29, the day after the ARRL Field Day, produced some interesting Es openings on 50 MHz. The day started with UT1FG/MM pounding into my FM18ap QTH from water grid FM92. He was in the K1HTV log at 1250Z. Less than 10 minutes later I worked Yuri again as he passed into another new grid, GM02. Six-meter-regular CT1HZE was worked at 1848Z, followed by C6AUX and CN8KD a few minutes later. UT1FG/MM was worked in yet another new grid, GM03, at 1913Z. At 2007Z I worked EA9IB in IM85, not having worked Pedro on 6 meters for over 15 years. Back in 1993 the K1HTV contact with EH9IB (the call he was assigned back then) was the first ever USA to EA9 QSO on record on 50 MHz.

“As June 29 progressed, at 2116Z UT1FG/MM was worked again, now in grid GM13, the 4th new grid for me today on the Magic Band. In the last hour of the UTC day other DX stations worked included PJ5A, J69MD, VP2ETE and J69DS.

“UTC June 30 started off with a bang. With the MUF over 150 MHz just SW of my FM18ap QTH, 2 meter stations northeast of me in W1, W2 and W3 land were working into a number of southern states. A cloud over northeast Tennessee produced enough ionization for my only 144 MHz Es QSO when I worked WA4ZZW in EM64 in Alabama.”

David Moore sent this link, to a piece about a spectral slicing satellite revealing the anatomy of a solar flare:

Jon Jones, N0JK, wrote: “I worked C6AUX at 1509z and PJ5A at 1921z on 50 MHz June 28 from the Kansas City Veterans Administration Parking lot. This was via sporadic E. C6AUX was loud at times, PJ5A not as strong.”

Jon says he works at the VA hospital part time in the Emergency Department, and when he wasn’t busy on Sunday he took some time to get on 6 meters. The area he operated from has a clear shot to the Southeast across the Blue River Valley. He pressed a 5/8 wave 2 meter antenna into 50 MHz service, where it operates as a 1/4 wave vertical. You can see a picture at . (This link does not work for me with Internet Explorer, but only Firefox for some reason.)

Jon also wrote, “KI0I also worked C6AUX while mobile June 28 from EM28 on 6. He used a homemade J-Pole fishing rod antenna on his truck. He also logged 6Y5WJ.”

On July 2 Jon wrote, “June 30 and July 1 - JW7QIA Svalbard made numerous contacts on 6 meters to North America. He worked C6AUX for the first Bahamas to Svalbard 50 MHz contact.

“Svalbard is near the North Pole and not in the mid-latitude Es zone. What is the propagation mechanism to North America? Perhaps Aurora Es on to mid-latitude sporadic Es.”

This just in: The World Data Center Sunspot Index and Long Term Solar Observations from the Royal University of Belgium has finally transitioned to a new International Sunspot Number system, and has completed extensive revisions to the sunspot record, going back centuries.

You can read about it here:

The numbers used in this bulletin are the Boulder sunspot numbers, and will not be affected.

And finally, at the end of June it is time to look at our 3-month moving average of daily (Boulder) sunspot numbers. The latest data is centered on May 2015, and includes all daily sunspot numbers from April 1 through June 30. The numbers for January through May 2015 are 98.2, 78.1, 68.2, 72.4 and 77.7. The cycle peaked during the periods centered on February and March 2014 when the moving averages were 146.4 and 148.2. The data centered on February 2014 included all daily sunspot numbers from January 1 through March 31. The average centered on March 2014 included all daily sunspot numbers from February 1 through April 30. This shifting 3-month average smoothes the numbers, making it easier to identify shifts in the solar cycle.

For more information concerning radio propagation, see the ARRL Technical Information Service at For an explanation of the numbers used in this bulletin, see An archive of past propagation bulletins is at More good information and tutorials on propagation are at

Archives of the NOAA/USAF daily 45 day forecast for solar flux and planetary A index are in downloadable spreadsheet format at and .

Click on “Download this file” to download the archive and ignore the security warning about file format. Pop-up blockers may suppress download. I’ve had better luck with Firefox than Internet Explorer.

Monthly propagation charts between four USA regions and twelve overseas locations are at

Instructions for starting or ending email distribution of ARRL bulletins are at

Sunspot numbers for June 25 through July 1 were 33, 28, 25, 39, 36, 41, and 49, with a mean of 35.9. 10.7 cm flux was 101.8, 101.2, 97.3, 97.3, 97.1, 100.8, and 109.6, with a mean of 100.7. Estimated planetary A indices were 33, 10, 9, 13, 6, 6, and 5, with a mean of 11.7. Estimated mid-latitude A indices were 19, 9, 8, 12, 6, 8, and 6, with a mean of 9.7.