The K7RA Solar Update


We saw another week with no sunspots, which were last observed just briefly over two weeks ago on two days, March 8-9. reports that so far in 2020, the percentage of days that have no sunspots is the same as all of 2019, when it was 77%.

Last week we saw the spring equinox, always a good seasonal indicator for better HF propagation.

Last week’s bulletin ARLP012 reported the average daily solar flux at 70.1. This reporting week is just one point higher on average, at 71.1.

Geomagnetic indicators remain quiet, with average planetary A index at 7.7, a little higher than the previous week’s average, which was 5.9. Average mid-latitude A index was also 5.9, up from 4.1 last week.

This point in the solar cycle is a great time for 160-meter propagation because of quiet geomagnetic conditions, although as the seasons change, we no longer enjoy those long winter nights, and will eventually see the return of summer conditions with increased atmospheric noise.

Predicted solar flux for the next 45 days is 71 on March 27 through April 3, 70 on April 4, 72 on April 5-18, 70 on April 19 through May 1, and 72 on May 2-10.

Predicted planetary A index is 5 on March 27-29, 12 on March 30-31, 8 on April 1-3, 5 on April 4-5, then 10 and 8 on April 6-7, 5 on April 8-13, then 8, 12 and 8 on April 14-16, 5 on April 17-22, then 12 and 8 on April 23-24, 5 on April 25 through May 2, 10 and 8 on May 3-4, and 5 on May 5-10.

Geomagnetic activity forecast for the period March 27 until April 22, 2020 from F.K. Janda, OK1HH of the Czech Propagation Interest Group, who has been compiling this report for the past 42 years.

Geomagnetic field will be
quiet on: April 10
quiet to unsettled on: March 30, April 2-3, 7, 11-13, 20
quiet to active on: (March 27-29,) 31, April 1, (4-6, 8-9, 16-19)
unsettled to active on: (April 14-15, 21-22)
active to disturbed: None

Solar wind will intensify on: March (28-31), April (1-6,) 9, 12-13, (15,) 16-19, (20)

- Parenthesis means lower probability of activity enhancement.
- The predictability of changes remains lower as there are no indicators.

This is probably unrelated, but I happened across this video of OK1HH, with CW on the soundtrack:

Chip, K7JA, reports from his shack in Garden Grove, California. "Between 0238 and 0338 UTC on March 23 (the evening of March 22 Pacific Time, 1938-2038 local), I worked 3D2AG, VK4WDM, JR6EZE, and KH6U on 28 MHz FT8. Several other Australian and Japanese stations were heard at the same time. 3D2AG was loud enough to have been a solid almost-local-sounding contact on FM!

“In the same time frame but extending later in the evening (until 0410 UTC or 9:10 PM local), 15 meters was alive with Asian and Pacific stations including Hong Kong, China, Japan, Indonesia, and even JD1BHA on Ogasawara Island.

“Twenty meters was open to the Pacific and South America until almost midnight local time.

“It's fun to catch these little "tidbit" openings; they give hope for better propagation ahead! Hope all is well--stay away from the corona bugs!"

Corona Bugs? Weren't they a brand of semi-automatic keys?

Here is the latest from WX6SWW, who sees evidence that our Sun continues to wake up:

Upcoming, this weekend is the CQ World Wide WPX Contest, SSB:

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For more information concerning radio propagation, see and 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

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Sunspot numbers for March 19 through 25, 2020 were 0, 0, 0, 0, 0, 0, and 0, with a mean of 0. 10.7 cm flux was 72.1, 71.7, 70.8, 70.2, 70.4, 71.2, and 71.2, with a mean of 71.1. Estimated planetary A indices were 12, 7, 8, 7, 12, 4, and 4, with a mean of 7.7. Middle latitude A index was 7, 5, 5, 7, 10, 4, and 3, with a mean of 5.9.




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