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The K7RA Solar Update


After six days with no visible sunspots, a new one appeared on Wednesday, August 1, with a daily sunspot number of 11. As there was also only one day with a sunspot (also 11) in the previous week, average daily sunspot number for this week was unchanged at 1.6. The new sunspot is small and was given the number AR2717 on Thursday, when the sunspot number again was 11.

Average daily solar flux was down from 68.4 to 68. Average daily planetary A index decreased from 8.1 to 5, while average daily mid-latitude A index went from 8 to 5.1.

According to an August 2 forecast prepared by the US Air Force, predicted solar flux is expected to be 70 on August 3, 72 on August 4-9, 71 on August 10, 70 on August 11-17, 68 on August 18-20, 66 on August 21-23, 68 on August 24 through September 6, 70 on September 7-13, and 68 on September 14-16.

Predicted planetary A index is 8 on August 3, 10 on August 4-5, 6 on August /6, 8 on August 7-8, 5 on August 9-11, 8 on August 12-13, 5 on August 14-15, then 8 and 12 on August 16-17, 5 on August 18-19, 20 and 12 on August 20-21, 5 on August 22 through September 1, then 10 and 8 on September 2-3, 5 on September 4-7, 8 on September 8-9, 5 on September 10-11, 8 and 12 on September 12-13, 5 on September 14-15 and 20 on September 16.


Reader Max White, M0VNG, of Worcester, England sent this about experiments with ionospheric sounding over 50 years ago, both below and above the ionosphere:


Jeff, N8II, wrote: “There has been sporadic E to somewhere every day on 10 meters in the past week, but today, August 2nd, was absolutely amazing. It all started with working MW0EDX in Wales on 15-meter CW via sporadic E with a good signal at 1815Z. Then, I called CQ on 15 CW and DL4KCA answered. He was 589 and was using a 3 element SteppIR Yagi antenna; we tried 12 meters and he was 549 (my antenna is a 2-element vs 5-element Yagi on 15 and 10 meters), and 549 on 10-meter CW.

“I worked Fred, F5NBX, a 10-meter CW regular, just after Joe and tried more CQs on 10 and 15 meters to no avail. Then, the big surprise happened at 1905Z when I heard Vlad, R2KW, with a 549 signal on 10 CW from Kaliningrad; with just one try I was in his log. Then, the following stations answered my CW CQs: UA3EDQ, RZ3AK, and RQ3A in Moscow, RU2K in Kaliningrad, and UX7IB and UX2VA in Ukraine -- all with S2 to 3 signals.

“In the 1900Z hour, I had a few western European stations call on CW from Germany, France, the Netherlands (a new DXCC band slot since 1/17) and Belgium (a new slot). I then found OH0Z on Aland Island who was 549 (another new slot)! This was followed by 9A2018CRO in Croatia, and more from Italy, Germany, France, and England.

“The 2000Z hour was relatively quiet with Hristo, LZ2HR, found at 2010Z and Q5 copy for the next 2 hours! Also, on 10-meter CW, I worked one each in Spain, Italy, and England.

“I was about to shut down for dinner at 2100Z when a few new stations appeared. On SSB, Ian, MM0TFU, called in very weak followed by CW contacts with OH0Z now 559, as well as Germany, Spain, and Robert, S50R, in Slovenia. Then, at 2122-2151Z, conditions markedly improved and on SSB I ran 30 European stations, all in Germany, England, Spain, France, Italy, the Netherlands, Belgium, and Portugal. The last few minutes were spent chasing DX cluster spots and spotting some stations of my own on CW, working ZB2FK in Gibraltar (a new slot), KL7SB/VP9 in Bermuda (a new slot), LZ3ZZ, TA1D in Istanbul, Turkey (new slot), and MU0FAL in Guernsey at 2205Z. After a dinner break at 2246Z, the band seemed to have closed to Europe, but VY2CAK on Prince Edward Island was S9+.

In my 47-plus-years of operating, I had never worked Russia, Kaliningrad, Ukraine, Aland Island, or Turkey on 10 meters via sporadic E during the summer months; it was an incredible opening!” (When Jeff says “new slot” it refers to the first time working a DXCC country on a particular band, as he explained above. – K7RA)


Jon Jones, N0JK, in Lawrence, Kansas sent this on August 2: "Usually, the sporadic E season winds down in August. But so far it has been going strong. There was a big E opening on 6 meters August 1 from Japan to the southeast states. N0LL and I heard CT1HZE into Kansas August 1. On August 2, Europe was in for hours as far west as the Mississippi River. Why such good conditions? One wonders if there is a connection to the fact that this has also been a great season for NLC (noctilucent clouds). They form at 85 km altitude. The E-layer is 90 - 160 km high. Perhaps the same upper atmosphere conditions keeping NLC going strong may be influencing sporadic E. See"

Note that has a gallery of images devoted to NLC:


Frantisek Janda, OK1HH sent the following from Ondrejov in the Czech Republic. See his bio on for more about him.

"Geomagnetic activity forecast for the period August 3-29, 2018.

Geomagnetic field will be:

Quiet on August 5, 10-11, 15, 23-24

Quiet to unsettled on August 14, 16, 22

Quiet to active on August 3-4, 6-9, 12, 25-29

Unsettled to active on August 12, 17-19, 21

Active to disturbed on August (13,) 20

Solar wind will intensify on August (16-19,) 20-22, 28-30


- Parenthesis means lower probability of activity enhancement.

- Reliability of predictions remains low."


Dr. Tamitha Skov sent this, followed by her video for this week: “Last week I mentioned traveling was always an adventure and this trip has been no exception. After being unable to connect to the television in my hotel room (I tried with two separate computers), I settled for shooting my forecast using my mobile phone camera in a way it was never intended. The result has been an unconventional video to say the least! I almost didn't post it, as it's not up to my usual standards, but I figured you would forgive the imperfections in favor of the content.

“Additionally, I apologize for getting this newsletter out to you a little late this week. Spotty internet connection while on the road has prevented me from sending it out until today. However, being mobile in Europe this week has given me the chance to reflect on how deeply entrenched space exploration is in our global culture. In fact, while in Amsterdam I came across an art installation showing an astronaut impossibly balancing between a chair and a flower pot (see The Joseph Klibansky installation, called "Self-Portrait of a Dreamer," succinctly captures our culture's dreamy fascination with space and its intersection with objects in our more ordinary lives.

“As I stared up at this massive structure, the symbolism began to sink in. I realized we are a lot like that dreamy astronaut, striving to blend our understanding of space with its impacts on our everyday world. I also realized that just like the astronaut, we too will one day soon strike a perfect balance.

“This week's forecast brings us an Earth-directed stealthy solar storm followed by a small pocket of fast wind that will likely have little effect but could bring subtle aurora to high latitudes. Even though GPS users might experience glitchy reception near aurora, users at low latitudes should enjoy better than normal reception due to the light impact of the storm. The Sun also has two bright regions rotating into Earth-view this week that should help keep amateur radio propagation near marginal levels, so there is some good news for everyone!

“Cheers, Tamitha"

See her latest video here:


For more information concerning radio propagation, see the ARRL Technical Information Service at For an explanation of numbers used in this bulletin, see

An archive of past propagation bulletins is at More good information and tutorials on propagation are at

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 July 26 through August 1, 2018 were 0, 0, 0, 0, 0, 0, and 11, with a mean of 1.6. 10.7 cm flux was 66.2, 66.6, 67.9, 68, 68.3, 68.9, and 70.2, with a mean of 68. Estimated planetary A indices were 4, 4, 5, 5, 5, 6, and 6, with a mean of 5. Estimated mid-latitude A indices were 6, 4, 6, 5, 5, 5, and 5, with a mean of 5.1.