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The K7RA Solar Update


Solar activity made a strong comeback this week, with the average daily sunspot number on December 11-17 rising 57 points to 145.4 from the previous seven days, while average daily solar flux was up 28.1 points to 167.7.

But then toward the end of the week, activity made a large jump, with solar flux at 213.2 on Thursday.

Predicted solar flux is 220, 225, 220 and 210 on December 19-22, then 200, 195, 190 and 160 on December 23-26, then 140 on December 27-29, 135 on December 30 through January 1, 140 on January 2-4, 145 on January 5, 155 on January 6-7, 160 on January 8, and 165 on January 9-12. Flux values then peak at 175 on January 14-15.

Predicted planetary A index is 10, 15, 10 and 8 on December 19-22, 5 on December 23-27, 8 on December 28-30, 10 on December 31 and January 1, then 12, 25, 15 and 10 on January 2-5, 8 on January 6-7, 10 on January 8-9, and 8 on January 10-12.

OK1MGW graces us with another of his geomagnetic forecasts. He expects (although is uncertain about) quiet to active conditions on December 19, mostly quiet December 20-21, quiet on December 22, mostly quiet December 23-24, quiet on December 25-26, quiet to unsettled December 27-28, mostly quiet December 29-31, quiet to unsettled January 1-2, active to disturbed on January 3, quiet to active January 4-5, quiet to unsettled January 6-7, quiet to active January 8, quiet to unsettled January 9-10, quiet to active January 11, and mostly quiet January 12-14.

He expects increased solar wind on January 2-5 and 8-11.

Peter Kolman, OK1MGW, of the Czech Propagation Interest Group, has been producing weekly forecasts with OK1HH since 1978.

On December 17 the 10.7 cm receivers at Penticton must have become overloaded, because NOAA/USAF adjusted the noon reading down from 198.5 to 192, which correlates to the earlier 10:00 AM reading of 191.5, rounded off.

We saw something similar on November 24, but in the opposite direction. The three flux readings for the day were 170.1, 144.4, and 168.4 at 10:00 AM, noon and 2:00 PM. It is always a rounded off noon reading that NOAA reports, but this time it was bumped up from 144.4 to 172, I suppose to be more consistent with the other readings. I’ve never noticed this before.

We saw another lowering of the reported flux number on November 5 when the three readings were 135.7, 145.2 and 136.3, but NOAA reported 135 for the day.

At 0105 UTC on December 18 the Australian Space Forecast Centre issued a geomagnetic warning. They said to expect a CME impact on December 19-20, resulting in increased geomagnetic activity. The warning says to expect unsettled to active geomagnetic conditions on December 19 and active conditions on December 20.

We received some great reports this week. First Jimmy Mahuron, K9JWJ, of Salem, Indiana wrote “10 meters still going strong” on December 13, and said running 25 W into an inverted-V he worked about two dozen stations in Colorado, California, Oregon, Utah, Iowa, Canada and England.

Dennis Condron, K0LGI, of Marion, Iowa sent some information on using distant broadcast television signals to detect meteor trails. He says Stan Nelson, KB5VL, in Roswell, New Mexico also does this, and has a web site, which displays their results. One display at shows Dennis’s results during the recent Geminid meteor shower. I think we can assume that all these displays are quiet most of the time, and that there are no local broadcasters using the same channels.

Also check

A couple of reports came in over the past day from people who worked ZL1RS on six meters.

Craig Hill, K3PLV, of Erie, Pennsylvania reports, “At 0011Z on December 15 I worked ZL1RS on six meters. He was a true 559 when I worked him. I did not listen after I worked him so he may have even gotten stronger later. This is a new one for me on six. Usually propagation to New Zealand just does not get this far north and east on six. I live in Erie PA and envy the six meter propagation the stations have in the southern part of the US. The solar flux index was 166. I don’t think that’s high enough for F2 on six and it wouldn’t be transequatorial propagation. So I’m confused how this happened. I saw no other stations spotted in the Pacific except a few VKs just to Central and South America. I run 1000 W to a 10 element Yagi on six. ZL1RS uses a homebrew 7 element Yagi on a 9.6 meter boom and an amplifier.”

I suspect it was a lucky coincidence of two E-skip paths linking up. And currently we are in the second (and smaller) annual E-skip season. From the signal report it looks like he was using CW.

We received another report from Bruce Smith, AC4G, of Taft, Tennessee, which is just about two miles north of the border with Alabama and about 80 miles directly south of Nashville.

“Very excited about my six meter CW QSO made on December 14 at 0020Z on 50.103Mhz with ZL1RS. Signal reports both ways were 559. ZL1RS peaked to S7 just before fading into the noise and gone in about 2 minutes, never to be heard again. This is the first ZL I have ever heard on 6 meters in EM65 southern Tennessee the black hole of the US. Just thought I'd pass this along.

“Worked the ARRL 10 meter contest last weekend running 4.5 W and was able to make QSOs to South America, Alaska, Hawaii, and as far away as Japan Sunday afternoon during 2 hours of operating.”

Sounds so great!  Thanks, Bruce.

Since the two contacts with the same New Zealand station were about 24 hours apart, I am wondering if instead of occurring on subsequent days, they were actually just a few minutes apart. Just from my experience with these sorts of things, I suspect they both occurred on December 14 in North America time, but K3PLV used the actual UTC date (the next day), but maybe AC4G reported his local date, while reading the UTC time off his clock? It happens! I’ve made the same mistake in the past. The same confusion often arises when trying to figure out when the contest begins. If it is 0001 UTC Saturday, then here on the Left Coast it is 4:01 PM PST Friday.

Don’t forget the ARRL CW Rookie Roundup this weekend. If you received your license in 2012, 2013 or 2014, you are a Rookie and eligible to compete. The rest of us are encouraged to participate, work the newcomers, and submit check logs. See for all the details.

Also, remember that Straight Key Night is less than two weeks away! Dust off that old straight key and spend a mellow night operating and welcoming the New Year. See for details. This is another test of your UTC savvy, mentioned above. It begins on January 1, in the New Year, at 0000 UTC. That is 7:00 PM EST on New Year’s Eve, December 31, 2014.

John Parnell, K7HV, sent this in from Seattle, after responding to my query about 10 meters last weekend: “I did not do the contest seriously. I did note that the fallout from the CME and resultant high A index knocked out most of the path to Europe, I only worked Spain and Canary Isle, in a short AM EU opening from the Pacific NW. The band was open elsewhere but a bit noisy, more so on Sunday. Decent N-S path to Oceania and S Atlantic, VP8RAF was very loud, decent openings to E/SE Asia in the afternoons.

“By the way, I finally figured out a way to load my G5RV on 160 (by shorting the ant and using an external tuner vs my rig's autotuner- duh!). I was therefore able to get on the ARRL 160 contest - my first time on the band in years. With only a few hours of operating I worked 28 states and 5 VE provinces. That was fun!

“As is traditional for this time of year, I am working VUs on 20. Looking at my log, I see that I have only worked VU between late Oct and early January…all long-path.”

And another Northwest ham, who wishes to remain anonymous, sent this:

“Are you kidding? It was great! Limited EU of course, with the limited sunlit area on N Hemisphere in mid-December. And I understand there was an unusual opening over the North Pole at our midnight, into EU which almost everyone out here missed. ZF2DX in Caymans did great. Kevin, N5DX, is his call. He is living there now. Many did very well.”

Check out this interesting Scientific American blog post about applying AI to solar prediction:

Also, this sounds like an interesting book combining art with science:

And further, I am reluctant to pass this on, except that it reflects the fears and concerns of some people who send me e-mail with questions, perhaps after doing a web search for “sunspot” or “solar flare” or “end of the world as we know it.” It’s funny.

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 11 through 17 were 115, 132, 121, 175, 152, 169, and 154, with a mean of 145.4. 10.7 cm flux was 147.5, 154.2, 159.8, 166.4, 169.3, 184.6, and 192, with a mean of 167.7. Estimated planetary A indices were 6, 21, 9, 11, 15, 8, and 8, with a mean of 11.1. Estimated mid-latitude A indices were 4, 15, 7, 9, 11, 7, and 6, with a mean of 8.4.





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