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The K7RA Solar Update


Sunspots appeared recently, all indicating cycle 25 due to their polarity, opposite from spots in cycle 24. Sunspots appeared December 24-26, and it looks like a new cycle 25 spot on January 1. NOAA did not report it (too weak?) but reported a sunspot number of 11 on January 1.

On January 2 NOAA reported the new spot with a sunspot number of 23.

Sorry, but the final propagation bulletin of 2019 was not sent out due to a misunderstanding on my part, so the usual paragraph of numbers at the bottom of this bulletin has an additional paragraph for last week.

Predicted solar flux for the next 45 days is higher than recent forecasts. Solar flux is predicted at 72 on January 3-10, 70 on January 11, 72 on January 12-25, 70 on January 26 through February 7, and 72 on February 8-16.

Predicted planetary A index is 5 on January 3-13, then 12 on January 14-15, 5 on January 16-25, 8 on January 26-28, 5 on January 29 through February 9, 10 on February 10-11, and 5 on February 12-16.

Geomagnetic activity forecast for the period January 3-29, 2020 from F.K. Janda, OK1HH.

Geomagnetic field will be
quiet on January 3-4, 8, 29
quiet to unsettled on January 5-7, 9-13, 18-21, 25-28
quiet to active on (January 14, 17, 22-24)
unsettled to active on (January 15-16)
No active to disturbed days predicted

Solar wind will intensify on January (14,) 15-16, (17, 22-24)

Parenthesis means lower probability of activity enhancement.

Everything suggests that we are very, very close to the minimum of the 11-year cycle.

Dick, K1HC, wrote on December 31: "I was on FT8 on 2 meters yesterday from home in FN42 (400 watts and four 12-element Yagis) at about 1630 UTC, and I was watching the PSK Reporter website to see if I was reaching any other stations. I saw that K2DRH in EN41 had received my FT8 signal at -14dB. With that being over 900 miles away, I went to the ON4KST chat page and tried to contact K2DRH there without luck. He was logged in but may have been tied up or away from the computer.

“I am wondering if it was a meteor scatter long burn rather than sporadic E propagation. However, I switched to MSK144, and I did not see any pings from any other stations. I went to higher power, about 700 watts, and had no further spots on the PSK Reporter from the Midwest.

“I thought you would be interested in the unusual propagation. I will hope for more of it during the ARRL VHF contest in January from FN53 in Maine!"

Goodness! 48 elements in phase and 400 watts with FT8? With that gear, seems like anything may be possible.

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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 December 19 through 25, 2019 were 0, 0, 0, 0, 0, 24, and 23, with a mean of 6.7. 10.7 cm flux was 69.9, 70, 70.6, 71, 72.6, 72.7, and 72.1, with a mean of 71.3. Estimated planetary A indices were 13, 5, 5, 4, 4, 3, and 4, with a mean of 5.4. Middle latitude A index was 12, 4, 4, 2, 2, 2, and 3, with a mean of 4.1.

Sunspot numbers for December 26, 2019 through January 1, 2020 were 11, 0, 0, 0, 0, 0, and 11, with a mean of 3.1. 10.7 cm flux was 72.1, 72.4, 72.2, 72, 70.9, 70.5, and 71.8, with a mean of 71.7. Estimated planetary A indices were 5, 3, 2, 2, 3, 4, and 3, with a mean of 3.1. Middle latitude A index was 3, 2, 0, 0, 2, 4, and 3, with a mean of 2.




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