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The K7RA Solar Update

08/10/2018 reported on August 8, 2018 that “Solar minimum conditions are in effect. The Sun has been without sunspots for 39 of the past 42 days. To find a similar stretch of blank suns, you have to go back to 2009 when the Sun was experiencing the deepest solar minimum in a century. Solar minimum has returned, bringing extra cosmic rays, long-lasting holes in the Sun's atmosphere, and strangely pink auroras."

For the third week in a row, we report an average daily sunspot number of 1.6. Why? It seems that in the past three reporting periods (including this week) there was only one day with any sunspots and each time that daily sunspot number was 11.

Average daily solar flux rose slightly from 68 to 69.7, while average daily planetary A index rose from 5 to 5.7, and average mid-latitude A index changed from 5.1 to 6.9.

Predicted solar flux is 70 on August 10, 69 on August 11-22, 70 on August 23-31, 69 on September 1-18, and 70 on September 19-23.

Predicted planetary A index is 5 on August 10-11, then 8, 10, 8, 5, 12, and 10 on August 12-17, 5 on August 18-19, then 20 and 12 on August 20-21, 5 on August 22 through September 1, then 8, 12, 12 and 8 on September 2-5, 5 on September 6-7, 8 on September 8-9, 5 on September 10-11, then 8 and 12 on September 12-13, 5 on September 14-15, then 20 and 12 on September 16-17, and 5 on September 18-23.


OK1HH sent us this:

"Geomagnetic activity forecast for the period August 10 to September 5, 2018.

Geomagnetic field will be:

Quiet on August 15, 22-24, 30

Quiet to unsettled on August 10, 12, 18, 25-29, September 2, 4-5

Quiet to active on August 11, 13-14, 21, September 1, 3

Unsettled to active on August 16-17

Active to disturbed 19-20

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


- Parenthesis means lower probability of activity enhancement.

- Reliability of predictions remains low."


Dick Ferry, K2KA, in Westford, Massachusetts had this 6-meter report: "On August 4, 2018 we had another epic opening on 6 meters from the east coast. From 2129z to 2254z European stations were coming in on FT8. There were so many, I had to scroll the receive window. I worked three new countries: SV9, E73, and YT9. Heard many more that I couldn't work: 4X, OD5, ZB, LY, OZ, TK, and UT7.

“It was not quite as good as the June 13, 2016 opening which lasted over 3 hours, but very good. Sometimes it is hard to work DX on FT8 when there is a lot of fading. It's luck to catch the signals right. This opening was solid though with signals as high as +10."


John Pieszcynski, W2FV, wrote: “I lamented to my wife that not only do I have to deal with low sunspots and a new in the Pacific Northwest (Washington), I now have to battle holes in the ionosphere! Thank God for FT8.” Click here to see what John is talking about:


Tamitha Skov sent this report on Thursday, August 9:


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 August 2 through 8, 2018 were 11, 0, 0, 0, 0, 0, and 0, with a mean of 1.6. 10.7 cm flux was 69.9, 70.2, 70.4, 69.2, 69.1, 69.5, and 69.6, with a mean of 69.7. Estimated planetary A indices were 6, 6, 5, 4, 4, 10, and 5, with a mean of 5.7. Estimated mid-latitude A indices were 6, 6, 8, 6, 5, 11, and 6, with a mean of 6.9.




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