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The K7RA Solar Update


Average daily sunspot number for the past week (December 1-7) was 40.9, up 10 points from the previous seven days at the end of November.

Average solar flux changed hardly at all, moving from 82.6 to 82.2.

Average daily planetary A index dropped from 13.6 to 4.9, and average mid-latitude A index from 10.3 to 3.4

The latest prediction from NOAA and the US Air Force shows solar flux at 75 on December 9-10, 70 on December 11-15, 78 on December 16-18, 82 on December 19-20, 86 on December 21-27, 84 on December 28-31, 82 on January 1, 80 on January 2-3, 78 on January 4-8, 80 on January 9, 82 on January 10-15 and 84 on January 16-17.

Their latest projection for Planetary A Index predicts 20, 18, 12 and 8 on December 9-12, 5 on December 13-17, then 8, 12, 16 and 22 on December 18-21, then 30, 12, 10 and 8 on December 22-25, 5 on December 26-31, then 8, 5, 12 and 15 on January 1-4, 20, 18 and 12 on January 5-7, 5 on January 8-13 and 8, 12, 16, 22 and 30 on January 14-18.

Here is a summary of our recent 3-month moving average of observed daily sunspot numbers, beginning in January 2016 through the end of November 2016. The averages were 55.4, 53.5, 49, 45.3, 43.1, 35.4, 33, 33.5, 40, 39 and 29.6.

Monthly average daily sunspot numbers for November were 22.4. This is down from 50.4, 37.4, and 29.1 for August through October.

No matter if we observe smoothed 3-month moving average sunspot numbers or monthly averages the downward trend in activity is obvious and undeniable.


F.K. Janda, OK1HH, sent us the weekly geomagnetic forecast from the Czech Propagation Interest Group.

“Geomagnetic activity forecast for the period December 9, 2016 to January 7, 2017

Geomagnetic field will be:

Quiet on December 14-17, 29-31, January 1

Mostly quiet on December 13, 18, 27-28, January 2

Quiet to unsettled on December 11-12, 26

Quiet to active on December 9-10, 19, 23-25, January 3

Active to disturbed on December 8, 20-22, January 4

Amplifications of the solar wind from coronal holes are expected on December 9-10 (11, 14-15, 18-20), January 2-3


- Parenthesis means lower probability of activity enhancement.

F.K. Janda, OK1HH”


And now, this news from Jeff, N8II, of West Virginia:

“It has been an interesting couple of weeks on the bands. The CQWW CW contest was tough on the low bands and the high bands, leaving only 20 meters in the daytime and early evening as a good option. At first, a disturbance caused all bands to be poor to Europe. It was not until Sunday morning on 20 meters that things really got rolling into northern Europe and Russia. My first QSOs with Norway, Sweden, Denmark, Estonia, and Latvia took place then, along with a good number of Russians. I could hear several Zone 33 west Africans on 160 meters on Saturday night, but they were still working one European station after another. Ten meters was barely open working only Morocco (barely), Brazil, Argentina, Uruguay, Chile, Venezuela, and Costa Rica and all 3 continental USA zones.

“A week later, the ARRL 160-meter contest featured good to excellent propagation. With low power and limited time, I worked all of the lower 48 states except WY and MT, and 12 DXCC entities including Ecuador, Costa Rica, EU Russia, Ukraine, Wales, Portugal, Sweden, and Germany.

“Another disturbance started Wednesday with 15 meters being almost completely closed after good signals the 2 to 3 days before from the UK, Germany, Greece, and countries southwest of there, along with an S9 signal from Per, LA8LLA at 1551Z on December 6.

“The low bands are finally opening well with some outstanding signals! On December 7, starting at 0320Z, I worked an S9+ 4O/KC0W in Montenegro, followed by stations in Lithuania, Latvia, and Slovenia.

“But the big excitement was tonight (December 8). For most of the last week, 3B9HA on Rodrigues Island at a heading of 71 degrees and a distance of 9770 miles has been spotted on 160, but nothing heard here. Tonight they were Q5 copy peaking around S9 and working quite a few USA stations on 160 meters, but I could not break the pile up. Right after giving up on 160, I found them on 80 meter CW peaking S9 + 20 dB! I made an easy QSO at 0110Z. In all of years on the bands, I have never heard an Indian Ocean station so loud on 80 meters. SFI is 79 and K has been running at 4 since about noon.”


This weekend, don’t miss the ARRL Ten Meter Contest. Predicted solar flux is 70-75, and planetary A index is projected to be 18 and 12 for both days. Last year, the contest was on December 12-13, and the solar flux was 116.7 and 122.5, while planetary A index was 12 and 8. On December 13-14, 2014 solar flux was 159.8 and 166.34, while planetary A index was 9 and 11. During the 2013 contest (December 14-15) solar flux was 164.2 and 156.2, while planetary A index was 16 and 7. See contest details at .

The ARRL encourages participants to try a new Web Log Upload app for this contest. See details at .

Solar activity is lower this year, but 10 meters still offers many opportunities, and is especially attractive to the “Little Pistols” (as opposed to Big Guns) contest operators. For casual operators, 10 meters is especially attractive because of the short wavelengths (and antenna lengths) involved.

For a half wave antenna cut to 28.3 MHz, that’s only 16 feet, 6 and 7/16 inches. A quarter wavelength is only 8 feet, 3 inches. Thus, a modest portable or temporary 10-meter installation can be used.

Here are some simple 10-meter antenna suggestions, some from an ARRL Facebook post of several years ago.


Finally, Take a look at GREGOR, all about a European space weather observatory:


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

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 December 1 through 7 were 49, 59, 62, 37, 37, 24, and 18, with a mean of 40.9. 10.7 cm flux was 84.5, 84.4, 84.7, 82.4, 82.7, 79.8, and 77.2, with a mean of 82.2. Estimated planetary A indices were 3, 4, 3, 2, 4, 7, and 11, with a mean of 4.9. Estimated mid-latitude A indices were 3, 2, 1, 1, 2, 6, and 9, with a mean of 3.4.